Berkeley Lab

RECENT ATAP NEWS

Laser, Biosciences Researchers Combine Efforts to Study Viruses in Droplets

Multiprong platform at the Berkeley Lab Laser Accelerator Center will produce X-ray images and chemical details

Originally published as a news release by Glenn Roberts, Jr. of LBNL Strategic Communications

Photo illustration of droplet containing highly magnified coronavirus

Photo illustration of droplet containing highly magnified coronavirus (credit: pxfuel.com)

Laser and biology experts at Lawrence Berkeley National Laboratory (Berkeley Lab) are working together to develop a platform and experiments to study the structure and components of viruses like the one causing COVID-19, and to learn how viruses interact with their surrounding environment. The experiments could provide new insight on how to reduce the infectiousness of viruses.

The new platform will build upon Berkeley Lab’s world-leading R&D efforts in laser-based plasma acceleration, in which a laser pulse creates an exotic, superhot state of matter known as a plasma that in turn rapidly accelerates charged particles – electrons and ions. Berkeley Lab scientists last year bested their own world record in accelerating electrons to high energies in a 20-centimeter span.

In the new setup, the accelerated electrons will generate X-rays that will act as microscopic strobes to capture images of virus-laden droplets that are dripped into the path of the X-rays. At the same time, synchronized within quadrillionths of a second, a second laser beam will strike the droplets to capture another layer of data about the virus particles and their makeup, and about other matter in the droplets.

“The idea is to learn about the virus and what’s around it,” said Thomas Schenkel, acting director of the Accelerator Technology and Applied Physics Division at Berkeley Lab who is part of the team planning the experiments. “How does it behave inside a droplet and what binds to it? How long is the virus viable in a droplet?”

The goal is to study the virus in certain biofluids, like saliva, and how it reacts to compounds mixed into the droplets. Biosciences experts at Berkeley Lab will prepare the samples and participate in the data analyses.

In this pilot study, researchers will use surrogate viruses that have similar properties to the SARS-CoV-2 virus that causes COVID-19 but are safe for laboratory workers to work with.

“These droplets aren’t just mini sacks of water, but a complex mixture of proteins and salt that affects viral stability,” said Antoine Snijders, a staff scientist and chair of the department of BioEngineering and BioMedical Sciences in Berkeley Lab’s Biological Systems and Engineering Division.

The droplets are intended to simulate the environment of the body’s respiratory system.

“What’s exciting about this study is that it will lead to a better understanding of the chemical characteristics of respiratory droplets and the virus contained within them,” Snijders added. “Once we understand the chemical characteristics, and the mechanism of viral inactivation within these droplets, we may be able to reduce efficiency of airborne disease transmission.”

The effort is supported by Berkeley Lab’s Laboratory Directed Research and Development (LDRD) program, through which the Lab directs funding to specific areas of research. Berkeley Lab, like the U.S. Department of Energy’s other national laboratories, is making COVID-19 research a priority.

The experiments will combine two techniques: X-ray imaging for structural information, and mass spectrometry to learn details about the chemical makeup of samples down to the level of individual proteins and molecules.

The secondary laser in the experiments will provide the spectroscopic information by charging up and breaking apart matter in the samples. Those bits and parts, such as individual protein components of a virus, can then be chemically measured and analyzed by a detector.

Image - This illustration shows the planned setup for laser-based virus droplet experiments at Berkeley Lab’s BELLA Center. A laser pulse (left, red) creates a plasma (light blue) that accelerates electrons (dark blue). The accelerated electrons produce X-rays (yellow) that are used to image virus-containing droplets (blue spheres at center). A secondary lasers (right, red) also strikes the droplets to capture mass spectrometry measurements of virus fragments (green). (Credit: Tobias Ostermayr, BELLA Center)

This illustration shows the planned setup for laser-based virus droplet experiments at Berkeley Lab’s BELLA Center. A laser pulse (left, red) creates a plasma (light blue) that accelerates electrons (dark blue). The accelerated electrons produce X-rays (yellow) that are used to image virus-containing droplets (blue spheres at center). A secondary laser (right, red) also strikes the droplets to capture mass spectrometry measurements of virus fragments (green). (Credit: Tobias Ostermayr, BELLA Center)

Conceivably, the setup could be used or modeled as a testing platform for coronavirus disease. Schenkel noted that with existing capabilities at the Berkeley Lab Laser Accelerator (BELLA) Center, it is possible to image and measure about five droplets every second. A proposed BELLA Center upgrade, called kBELLA, could drive that rate up to 1,000 droplets per second.

Eric Esarey, BELLA Center director, said an ultimate aim in developing laser plasma acceleration techniques is to reduce the size and cost of particle accelerators that could serve in a range of capacities for the medical, industrial, and research communities.

“In principle, this could be a compact, powerful, and low-cost device that could be put in lots of laboratories and lots of hospitals,” he said.

New types of X-ray sources based on laser-plasma accelerators are in active research in the BELLA Center, and they continue to be improved. These improvements are needed to provide high-resolution imaging of very small viruses in their environment.

While the BELLA Center is now offline due to shelter-in-place orders, Schenkel said that planning has started for the new experimental setup, with the goal of first experiments later this summer. A collaboration with biologists at the BELLA Center is ongoing, and there is already mass spectroscopy equipment that can be adapted for the new experiments.

Schenkel added that researchers can proceed with modifying a Berkeley Lab-developed computer code that models the laser and electron beams to optimize them for the new research.

“We are excited to use our tools to advance our understanding of COVID and contribute to future pandemic prevention,” Schenkel said.

“There are many analytical techniques that have originated from research with atom-smashers and particle beams years ago and that have since become workhorse tools in biomedical science.” Schenkel added, “When we discussed this new idea, there was a strong sense of urgency and excitement. This project is one example where we can immediately adapt our capabilities in response to the current crisis and advance our arsenal for the prevention of future pandemics. We want to show that this works so that we can establish it as a new capability for the community.”


APRIL 2020

Director’s Corner

As we move into the second month of the Bay Area’s shelter-in-place order (recently extended through May) and the Lab’s safe and secure status, I’d like to thank everyone for compliance with the need for remote work and social distancing.

At this writing, California has had some 41,000 confirmed cases of COVID-19… an alarming number, but remember that our state’s population of nearly 40 million is three orders of magnitude greater. Plainly we are doing a good job of protecting each other by staying home whenever we can, and by wearing cloth face coverings, paying attention to hygiene, and maintaining social distance when we must go out.

More …

Our leadership is just beginning evidence-based planning for how things might progressively re-open, and there is no way to predict how or when this will happen. It is safe to say that we will have to live and work in a new way for some time, and as Lab Director Mike Witherell pointed out in the recent online town hall, those of us who can telecommute should prepare to keep doing so for the foreseeable future. True, complete normalcy might not resume until a vaccine has been developed, proven safe and effective, and deployed widely.

Throughout, we all need to continue protecting each other.

California For All logo

Asked if the worst was over for California, Governor Gavin Newsom said, “If we all pull back, we could see a second wave that makes this pale in comparison. {…} Honestly, that’s determined by the act of 40 million Californians stepping in, continuing to meet this moment… “

Our research and development activities continue. In this issue of ATAP News, I would like to bring to your attention the progress our superconducting magnet program has helped bring to the LHC Luminosity Upgrade as part of a tri-lab collaboration, as well as an innovative electron source being developed into a unique materials probe together with the Molecular Foundry. And BELLA Center’s Jeroen van Tilborg was invited to write a perspective article on a recent breakthrough in laser-plasma acceleration.

I must end on a sad note: the passing of our colleague Max Zolotorev after a long illness. Max leaves a legacy of both physics insight and personal warmth that touched many of our lives and careers. His was truly the scientific life well lived.


FEATURED SCIENTIFIC RESEARCH

Three National Labs Team Up for Record-Setting HL-LHC Quadrupole Magnet

Adapted by Glenn Roberts, Jr., of Berkeley Lab Strategic Communications from a Fermilab original.

In a multiyear effort by three U.S. national laboratories, researchers have successfully built and tested a powerful new focusing magnet that represents a new use for niobium-tin, a superconducting material.

The U.S. Department of Energy’s Fermi National Accelerator Laboratory, Brookhaven National Laboratory, and Lawrence Berkeley National Laboratory (Berkeley Lab) designed, built, and tested the new magnet.

This video highlights magnet-making efforts to support the High-Luminosity Large Hadron Collider upgrade at CERN in Europe. Three U.S. Department of Energy national labs — Berkeley Lab, Fermilab, and Brookhaven National Laboratory — are building superconducting magnets that can produce far stronger magnet fields than the magnets now in place at the LHC. This will enable more particle collisions and data to help us learn more about exotic particles and their properties. (Marilyn Sargent/Berkeley Lab)
More …

The eight-ton device, about as long as a semitruck trailer, set a record for the highest field strength ever recorded for an accelerator focusing magnet, and raises the standard for magnets operating in high-energy particle colliders.

It is one of 16 that the three partners will deliver for operation in the High-Luminosity Large Hadron Collider (HL-LHC) at CERN in Europe, which is an upgrade of the existing LHC – already the world’s most powerful particle accelerator. The 16 magnets, along with another eight produced by CERN, will focus beams of protons to a tiny spot as they approach collision inside two different particle detectors. The U.S.-based team will also deliver four spare magnets.

Photo - a Magnet for the High-Luminosity LHC upgrade project. (Marilyn Sargent/Berkeley Lab)

This magnet was built by teams at Berkeley Lab, Fermilab, and Brookhaven National Laboratory for the High-Luminosity LHC upgrade project.
(Marilyn Sargent/Berkeley Lab)

In all, the upgrade will require 130 new magnets of 11 different types, produced by more than a dozen international partners. The project will replace about three-quarters of a mile of equipment at the LHC.

Niobium-tin is the ingredient that sets these U.S.-produced magnets apart. It is a superconducting material that produces strong magnetic fields. These will be the first niobium-tin quadrupole magnets ever to operate in a particle accelerator.

Superconductivity is a state achieved by extremely cooling the magnets to a temperature hundreds of degrees below freezing. In this state, the magnets can pass electrical current with virtually no electrical resistance in order to maintain a tight focus of the particle beams.

The LHC is already the planet’s most powerful particle accelerator, and its high-luminosity successor will smash together beams of protons cruising around the 17-mile ring at close to the speed of light.

The High-Luminosity LHC will pack an additional punch: With its more intense beams, it will provide 10 times the collisions that are possible at the current LHC. With more collisions there are more opportunities to uncover new physics. The new focusing magnets will help it achieve that leap in luminosity delivered to the experiments.

Berkeley Lab’s work is focused on winding wires into thin cables, measuring and analyzing those cables to ensure they meet exacting requirements, testing the quality of the magnetic fields generated by the cable-formed magnet coils, assembling the magnets into support structures, and ensuring their proper alignment and uniform compactness.

Giorgio Apollinari, head of the three-lab U.S. LHC Accelerator Upgrade Project and a scientist at Fermilab, said, “We’ve demonstrated that this first quadrupole magnet behaves successfully and according to design, based on the multiyear development effort made possible by DOE investments in this new technology.”

Kathleen Amm, Brookhaven Lab’s representative for the Accelerator Upgrade Project, said, “It’s a very cutting-edge magnet, really on the edge of magnet technology.”

The new magnets, with higher field strength than those of the existing LHC, can bring particle beams to a tighter focus, resulting in more collisions that generate more data.

Focus, magnets, focus

In circular colliders, two beams of particles race around a ring in opposite directions. An instant before they reach the collision point, each beam passes through a series of magnets that focus the particle beams into a tiny spot, much like a magnifying glass focusing light rays to a point. Now packed as tightly as the magnets can get them, the beams collide.

Even with the new magnets, most of the particles won’t collide; they continue their paths around the ring until they get another collision opportunity at the next detector. But many particles do smash into each other. That number, and the scientific fruitfulness of that smash-up, depends on how dense the beam is. The more particles that are crowded together at the collision point, the greater the chance of collisions.

You get those tightly packed beams by sharpening the magnet’s focus. One way to do that is to widen the lens.

Photo - Magnet testing at Berkeley Lab. (Marilyn Sargent/Berkeley Lab)

A magnet-testing instrument (center) is prepared for moving through the center of a magnet assembly at Berkeley Lab. (Marilyn Sargent/Berkeley Lab)

Consider the magnifying glass example: “If you try to focus the light from the sun using a magnifying glass at a small point, you want to have a more ‘powerful’ magnifying glass,” said Ian Pong, a Berkeley Lab scientist who oversees cable fabrication for the U.S. labs’ magnet effort. A larger lens has more light-gathering ability and stronger light-ray-bending power at its outer rim than a smaller lens.

In this analogy, the size of the lens is like a magnet’s aperture — the opening of the passageway the beam takes as it barrels through the magnet’s interior. If the beam is allowed to start wide before being focused, more particles will arrive at the intended focal point — the center of the particle detector. The U.S. focusing-magnet team widened the aperture to 150 millimeters, more than double the current LHC focusing magnet aperture of 70 millimeters.

But a wider aperture isn’t enough. There must be a strong magnetic field to actually focus the beam.

“The magnet has to squeeze the beam more powerfully than the LHC’s present magnets in order to create the luminosity needed for the HL-LHC,” Apollinari said.

To meet the demand, scientists designed and constructed a muscular focusing magnet. They calculated that, at the required aperture for the upgrade project, each focusing magnet would have to generate a field of between 11.4 and 12.4 teslas. This is up more than 50% from the 7.5-tesla field generated by the current niobium-titanium-based LHC magnets.

“So what do you do? You need to go to a different conductor,” Apollinari said.

Niobium-tin for the win

Magnet experts have been experimenting with one of those conductors, niobium-tin, for decades. Electrical current coursing through a niobium-tin superconductor can generate magnetic fields of 12 teslas – about 250,000 times stronger than the Earth’s magnetic field at its surface – and beyond.

But niobium-tin calls for entirely different magnet-construction techniques than the ones used with niobium-titanium, because the heat treatment that makes niobium-tin superconductive also makes it brittle.

“Once they’re reacted, it becomes a beautiful superconductor that can carry a lot of current, but then it also becomes brittle,” Apollinari said.

“If you bend it too much, even a little bit, once it’s a reacted material, it sounds like corn flakes,” Amm said. “You actually hear it break.” Niobium-titanium was easier to work with because it is pliable.

Over the years, scientists and engineers have figured out how to produce a niobium-tin superconductor in a form that is useful. Guaranteeing that it would hold up as an HL-LHC focusing magnet was another challenge altogether.

State-of-the-art physics and engineering makes the magnets

To produce large, intricate magnets that meet the demands of a collider, the group of three U.S. labs teamed up — each with its own areas of expertise and specialized facilities — under Fermilab’s leadership.

Photo - Spools of wire are wound into thinly pressed strips of cable at Berkeley Lab. (Marilyn Sargent/Berkeley Lab)

Spools of wire are wound into thinly pressed strips of cable at Berkeley Lab. The cable is wound to form niobium-tin magnet coils. (Marilyn Sargent/Berkeley Lab)

At Berkeley Lab, the magnet-making process begins by fabricating cable from 40 spools of wire — a copper matrix that contains niobium and tin. The machine-wound wires are rolled into thin, rectangular cables that must be defect-free and meet specifications within hundredths of a millimeter.

“Making these accelerator magnet cables is like directing 40 ballet dancers doing 5,000 pirouettes nonstop in a synchronized manner, where a single misstep would cost as much as crashing a few Tesla sportscars,” Pong said.

Scientists at Fermilab and Brookhaven wind these cables into coils, taking care to avoid excessively deforming them. Then comes a three-stage, weeklong heat treatment, causing a chemical reaction that makes the cables superconductive.

The magnet coils must be heated evenly, inside and out. “You have to control the temperature well. Otherwise the reaction will not give us the best performance,” Pong said. “It’s a bit like cooking. It’s not just to achieve the temperature in one part of the coil but in the entire coil, end to end, top to bottom – the whole thing.” Researchers make the coils strong and solid by embedding them in a resin.

It takes several months to yield a coil that is ready for service as one of a focusing magnet’s four poles. Together, the coils conduct the electric current that produces the magnetic field.

The magnet coils are assembled within an aluminum and steel support structure at Berkeley Lab to form a single magnet, and researchers test the magnetic fields produced by these coils and ensure that the support structure provides uniform pressure along the length of the coils.

Temporary water-pressurized metal bladders are used to provide tension to the support structure during assembly and alignment. The support structure is designed to withstand more than 20 million pounds of force during operation. Researchers use models and instruments to verify that the support structure can withstand the strength of the magnetic field.

Photo - This completed niobium-tin magnet coil will generate a maximum magnetic field of 12 tesla, about 50 percent more than the niobium-titanium magnets currently in Cern’s LHC. (Alfred Nobrega/Fermilab)

This completed niobium-tin magnet coil will generate a maximum magnetic field of 12 tesla, about 50 percent more than the niobium-titanium magnets currently in Cern’s LHC. (Alfred Nobrega/Fermilab)

“Because these coils are very powerful when they are energized, there is a lot of force trying to push the magnet apart,” Pong said. “Even if the magnet is not deforming, at the conductor level there will be a strain, to which niobium-tin performance is very sensitive. The management of the stress is very, very important for these magnets.”

Alignment of the four coils within each magnet is also critical to performance. “You need very high field precision, so we have to have very high precision in how they align these to get good magnetic-field uniformity,” Amm said.

The magnets are shipped to Brookhaven for testing, then to Fermilab for installation in their cryogenic containers, followed by another round of testing before shipment to CERN.

“This will be the first use of niobium-tin in focusing accelerator magnets, so it will be pretty exciting to see such a complex and sophisticated technology get implemented into a real machine,” Amm said. “These magnets are currently the highest-field focusing magnets in accelerators as they exist today.”

Pong added, “Finally we are coming to it, and we really want to make sure it is a lasting success.”

The many moving parts of an accelerator collaboration

Ensuring lasting success has as much to do with the operational choreography as it does with the exquisite engineering. Conducting logistics that span years and a continent requires painstaking coordination.

“For example, transportation communication: We have to make sure that things are well protected,” Pong said. “Otherwise these expensive items can be damaged, so we have to foresee issues and prevent them.”

Amm, Apollinari, and Pong acknowledge that the three-lab team has met the challenges capably, operating as a well-oiled machine.

“The technologies developed at Fermilab, Brookhaven, and Berkeley helped make the original LHC a success. And now again, these technologies out of the U.S. are really helping CERN be successful,” Amm said. “It’s a dream team, and it’s an honor to be a part of it.”

The team’s achievements are made possible by many years of R&D. The U.S.-based Accelerator Upgrade Project for the HL-LHC, of which the focusing-magnet project is one aspect, began in 2016. It grew out of a 2003 predecessor, the U.S. LHC Accelerator Research Program (LARP), that developed LHC-related accelerator technology. And these efforts drew upon past experience in pushing the frontiers of magnet and materials performance for a variety of applications.

From now until about 2025, the U.S. labs will continue to build the LHC magnets, from fine strands of niobium-tin to the hulking finished products. In 2022 they plan to begin delivering the magnets to CERN. Installation is planned in the following three years.

“People say that ‘touchdown’ is a very beautiful way to describe the landing of an airplane, because you have a huge metal object weighing hundreds of tons, descending from the sky, touching a concrete runway very gently,” Pong said. “Our magnets are massive superconducting devices, focusing tiny, invisible particle beams that are flying close to the speed of light through the bore. It’s quite magical.”

The magic starts in 2027, when the High-Luminosity LHC comes online.

The work, Apollinari said, is “a generational passing of the baton.”

“The upgrade project exemplifies what can be achieved through co-operation among the laboratories,” said Associate Laboratory Director James Symons. “The U.S. contribution to the luminosity upgrade has been made possible by the very successful LARP collaboration, which developed the design concept over the past decade.”

This work is supported by the DOE Office of Science.

To Learn More…

•    View the original Fermilab release.
•    CERN Ceremony Marks Groundbreaking for Accelerator Upgrade Involving U.S. National Labs
•    Successful Test of New U.S. Magnet Puts Large Hadron Collider on Track for Major Upgrade
•    An Advance in Superconducting Magnet Technology Opens the Door for More Powerful Colliders
•    World Record Magnet 300,000 Times Strength of Earth’s Magnetic Field



A Next-Generation Electron Source: Multi-Facility Collaboration Hits the Bullseye

—Brooke Kuei, Molecular Foundry

Conceptual diagram of bullseye lens

A schematic describing the geometry of the bullseye lens, showing the grating period (p), groove width (w), groove depth (d), and the center plateau radius (r)

Scientists have been using electrons to probe the structure of materials for decades. In recent years, researchers have manipulated electron beams to become small enough to study materials at the scale of individual atoms — and to pulse fast enough to capture subtle atomic movements.

However, it has been difficult to generate a beam that is both small and fast.

In a collaboration between Berkeley Lab researchers in the Accelerator Technology and Applied Physics Division (ATAP) and the Molecular Foundry, scientists have created a new kind of electron source that has the potential to overcome this hurdle.

The work, which was published Nov. 25, 2019, in Physical Review Applied, demonstrates the potential for a source made from a bullseye plasmonic lens that fires electrons as quickly as existing ultrafast electron beams but with a beam size that is hundreds of times smaller.

More …

“This research is the first part of a more complex and intriguing instrument that I’m thinking about, which will allow us to create ultrafast bursts of electrons emitted from a very small and confined space,” said Daniele Filippetto, a staff scientist at Berkeley Lab’s Accelerator Technology and Applied Physics Division and corresponding author of the study. Such ‘ultrafast’ bursts are quicker than the fastest chemical reaction ever studied.

Typical beam probes are relatively large; “it means your sample has to look the same over this entire field of view,” said Andrew Minor, director of the National Center for Electron Microscopy, a facility within the Molecular Foundry, and professor at UC Berkeley. “This works well for materials like graphene sheets that look the same everywhere, but we need a much smaller beam to look at things like individual nanowires and nanoparticles.” In materials with multiple components, this large beam size also prevents scientists from looking at the interfaces between different materials.

Atomic force microgram of bullseye lens

Atomic force microscopy (AFM) measurements of the surfaces of the bullseye lenses made using the typical focused ion beam method (left) and the new e-beam lithography method (right)

The electron source developed in this study is a gold surface with concentric circular grooves arranged in a bullseye pattern. When a laser hits the gold, the laser transfers energy to surface plasmons — electrons on the surface of the gold that move collectively — and the grooves cause them to ripple inward and outward. When the waves simultaneously hit the center of the bullseye, a small but intense beam of electrons is fired out from the center.

The problem with more conventional ultrafast electron sources is that the size of the beam when it hits the sample is approximately the width of a human hair, which is enormous compared to the nano-scale structures studied at the Molecular Foundry.

“It’s like when you throw a stone into a lake,” explained Filippetto. “You see these waves, but a few seconds after you throw that stone, you see a peak of water coming out where you have interference of the waves.”

The response time of the source is less than 10 femtoseconds (the time it takes for light to travel 3 micrometers), while its size is approximately 100 nanometers (approximately the width of a cell membrane).

Scanning electron microgram of bullseye lens

Scanning electron microscopy (SEM) images of the bullseye lenses made using the typical focused ion beam method (left) and the new e-beam lithography method (right)

For the emitted beam to be as bright as possible, the surface has to be extremely flat. In this case, an atomically flat surface was made using a new nanofabrication technique developed at the Molecular Foundry.

“A couple of years ago, we developed a method to make very smooth surfaces of gold with a peel-off process,” explained Stefano Cabrini, director of the Nanofabrication Facility at the Molecular Foundry. “So we’re able to put a pattern on silicon, deposit the gold onto the silicon, and then peel off the gold. We used this process on the bullseye and it worked.”

Although the electron source is designed to shoot out electrons when it is hit with light, its ability to do so was tested using the inverse technique: By shining electrons onto the source, the researchers were able to confirm its promising plasmonic behavior by measuring how light came out of it.

We have a very good collaboration between a group of people who understand each other, and we all put our best efforts forward.
— Daniele Filippetto

The key to the success of this project was the collaboration between different facilities within Berkeley Lab, Filippetto noted.

“Real breakthroughs come when you’re working at the boundaries between different disciplines,” he said. “This project wouldn’t have been possible without the Molecular Foundry. We have a very good collaboration between a group of people who understand each other, and we all put our best efforts forward. We’re seeing the results now.”

The possibility of an ultrafast, tiny electron beam opens up the doors for understanding chemical reactions and structural changes at molecular length scales, particularly for materials that do not look the same over a large area — such as nanoparticles — or for interfaces between different materials.

Moving forward, the team is working on improving the electron source with an improved design. The team also plans to measure electron yield and brightness in a test system, with the final goal of using the source as electron emitter in the HiRES beamline, an ultrafast electron scattering beamline at the Advanced Light Source.

Other directions include designs of nanostructure arrays for emission of large electron currents, exploring the temporal response of the structure to push to sub-femtosecond resolution, and plasmonic-based electron acceleration.

The Molecular Foundry is a DOE Office of Science User Facility.


NEWS IN BRIEF

Lining Up for Laser Plasma Acceleration

On March 31, 2020, Physics Review Letters published a paper by Palastro and colleagues from the University of Rochester, where a dephasingless laser-wakefield accelerator (DLWFA) was proposed. This proposed design for plasma accelerators would use line-focused laser pulses to overcome the problem of particles outrunning the acceleration region. To highlight this work, the American Physical Society asked Jeroen van Tilborg of ATAP Division’s Berkeley Lab Laser Accelerator (BELLA) Center to write a Viewpoint perspective, reproduced here, in their online magazine Physics. The DLWFA presents a clever way of shaping the spatial and temporal laser energy delivery onto a plasma, aimed at realizing a compact (room-size) high-energy electron accelerator. This goal is very much in-line with research in BELLA Center, where, over recent years, key community milestones on laser-plasma acceleration were demonstrated. This Viewpoint article and Palastro et al., Physical Review Letters 124, 134802 (31 March 2020), will help in appreciation of the various approaches being employed to pursue the same objectives: the compact production of multi-GeV electron beams and the development of novel “table-top” radiation sources.

Conceptual diagram of dephasingless wakefield acceleration

The proposed dephasingless wakefield acceleration would utilize two optical elements: an echelon (blue) and an axiparabola (green). A laser pulse would first strike the echelon, producing a series of time-staggered rings. The axiparabola would then focus these rings onto a line, consisting of multiple Rayleigh-length segments. This spatiotemporal laser control could generate a wakefield that travels at the speed of light, overcoming one of the main limitations to wakefield acceleration. (Illustration courtesy APS/Alan Stonebraker)

 

One way to accelerate particles is to fire an intense laser pulse into a plasma, creating a density wake whose electric field pushes charged particles like electrons to high speeds [1]. The accelerating gradient from such a plasma wakefield is much higher than can be achieved in conventional radio-frequency-based technology. However, a central difficulty with employing laser wakefield accelerators (LWFAs) is that the electrons eventually outrun the accelerating region of the laser-driven wakefield. Because of this dephasing, a single stage of wakefield acceleration is typically limited to a few tens of centimeters in length, and it is forced to operate at a low density, which constrains the accelerating gradient.

More …

Several ideas have been proposed to deal with this dephasing limit. A new idea from John Palastro and colleagues from the University of Rochester, New York, uses special optical components to focus the laser into points along a line, thus extending the wake region so electrons are accelerated for longer and at a higher gradient [2]. This method faces some hurdles, such as increasing the laser power above what’s currently available, but it has the potential to accelerate electrons to TeV energies over just a few meters.

The high gradients offered by laser wakefield acceleration open the path for tabletop accelerators at universities, hospitals, and smaller R&D labs, with applications such as x-ray bio-imaging, active nuclear interrogation, and medical treatments. LWFA also enables progress towards future TeV-scale particle colliders that promise to extend our understanding of the basic structure of the Universe [3]. In the past 20 years, the LWFA community has evolved from small-scale proof-of-principle demonstrations to milestones in the production of beams with high current, low emittance, and narrow (percent-level) energy spread. Precision control of the laser-plasma interaction with multiple lasers or density profile shaping is a central thrust in ongoing research. Efforts are also underway to increase the number of laser shots from a few per second to more than a thousand per second, which will benefit stabilizing feedback procedures and applications that require high flux.

The maximum achievable electron energy for LWFA is determined by the accelerating field strength and the length of acceleration Lacc, both of which are limited by laser and plasma physics [1]. The field strength scales with the plasma density as Ez∼n1∕2. At currently used densities (1016–1019 cm−3), the field strength can exceed 10–100 GV/m, which is about a thousand times the acceleration in traditional radio frequency cavities used at places like CERN. Ez also depends on the laser, whose intensity is determined by the laser energy, wavelength, pulse duration, and spot size.

The effective accelerator length depends on the laser as well. Specifically, the acceleration is limited to the region over which the laser remains focused. In vacuum, this focus region is characterized by the Rayleigh length zR, which is calculated with the laser wavelength and spot size. For most setups, the Rayleigh length is in the millimeter to centimeter range, but researchers can extend the focusing region by adding light-guiding structures, as was demonstrated in a recent LWFA experiment that achieved 8-GeV acceleration energies with a 20-cm-long waveguide [4]. However, guiding structures are not without challenges, including the need for precise alignment and transverse mode control to avoid damage from the high-power laser pulses.

Guiding structures also don’t alleviate the problem of dephasing. Dephasing occurs because the wakefield region travels behind the laser at a speed slower than the vacuum speed of light, so electrons accelerated to relativistic energies will eventually get ahead of it. As such, the wakefield speed places an upper limit on the acceleration length, which scales with density as n−3∕2. To increase this limit—and correspondingly increase the maximum electron energy—traditional setups use a low plasma density.

Recently, a group proposed a scheme to overcome this dephasing limit by obliquely intersecting two tilted-pulse-front lasers [5]. The interference between the lasers would generate a wakefield region that travels at the speed of light in vacuum. However, this approach requires precision control of two lasers, with potential challenges from transverse wakefield asymmetries.

Palastro et al. [2] have a similar idea for speeding up the wakefield region that uses a single laser and special optics rather than interfering lasers. Specifically, their proposed method combines an echelon (a mirror with specially designed steps) and an axiparabola (a recently developed curved mirror) [6]. As the team conceives it, a laser pulse would first strike the echelon, which divides the light into a number of concentric rings (Fig. 1). These rings would be separated in time, such that the outer rings arrive at the axiparabola ahead of the inner rings. The curved reflective surface of the axiparabola would focus the rings at successive points along a line. This spatiotemporal shaping of the laser pulse offers a way to generate a wakefield traveling at the vacuum speed of light, which would circumvent dephasing.

To see how this “dephasingless” LWFA compares to previous schemes, we can imagine the system is tuned so that each ring produces the same acceleration effect as a single laser pulse in the traditional nonguided LWFA. In other words, each ring generates a focal segment that is one Rayleigh-length long, and if there are N rings, the total acceleration length would be N times the Rayleigh length. In addition to increasing the acceleration length, dephasingless LWFA could operate at high plasma density, which means a higher accelerating gradient. The bottom line is that dephasingless LWFA could potentially reach higher electron energies than previous methods with the same acceleration length.

One potential hurdle to this proposal is the laser energy requirements. If each of the N rings is to produce a separate wakefield, then the single laser pulse would need roughly N times more energy than in a traditional LWFA of comparable laser intensity. For TeV-scale electron acceleration, the number of rings would need to be in the thousands, and the corresponding femtosecond-duration laser energy would be multiple kilojoules, which may pose a challenge in terms of the availability of laser systems and power consumption limitations (especially for kHz operation). There are other issues that may require further investigation, such as how well does the line-focus scale to large ring numbers, and how will the spatiotemporal laser evolution affect wakefield generation and laser-electron overlap. In addition, questions remain over the inverse accelerated charge scaling with plasma density [7].

Despite these uncertainties, Palastro et al. have provided a clever variation of staged acceleration, with independently timed laser “beamlets” driving acceleration without the need for intrastage optics or complex guiding structures. As such, dephasingless LWFA enables new opportunities in the choice of density and laser-plasma accelerator architecture. This could be of particular importance for leveraging future multipetawatt lasers to compactly create high-energy electron beams that can probe nonlinear quantum electrodynamics [8]. Next on the dephasingless LWFA to-do list: performing detailed simulations of laser delivery and wakefield production at multi-GeV scale and testing the waters regarding practical limitations.

Their research was published in Physical Review Letters 124, 134802 (March 31, 2020).

References

E. Esarey et al., “Physics of laser-driven plasma-based electron accelerators,” Rev. Mod. Phys. 81, 1229 (2009).
J. P. Palastro et al., “Dephasingless laser wakefield acceleration,” Phys. Rev. Lett. 124, 134802 (2020).
W. P. Leemans and E. Esarey, “Laser-driven plasma-wave electron accelerators,” Phys. Today 62, No. 3, 44 (2009).
A. J. Gonsalves et al., “Petawatt laser guiding and electron beam acceleration to 8 GeV in a laser-heated capillary discharge waveguide,” , Phys. Rev. Lett. 122, 084801 (2019).
A. Debus et al., “Circumventing the dephasing and depletion limits of laser-wakefield acceleration,” Phys. Rev. X 9, 031044 (2019).
S. Smartsev et al., “Axiparabola: A long-focal-depth, high-resolution mirror for broadband high-intensity lasers,” Opt. Lett. 44, 3414 (2019).
W. Lu et al., “Generating multi-GeV electron bunches using single stage laser wakefield acceleration in a 3D nonlinear regime,” Phys. Rev. Special Topics: Accelerators and Beams 10, 061301 (2007).
A. Di Piazza et al., “Extremely high-intensity laser interactions with fundamental quantum systems,” Rev. Mod. Phys. 84, 1177 (2012).

About the Author

Jeroen van Tilborg

Jeroen van Tilborg is an experimental staff scientist at the BELLA Center at Lawrence Berkeley National Laboratory (LBNL), California. Jeroen moved to Berkeley in 2001 for a combined Ph.D. program from LBNL and the Eindhoven University of Technology, Netherlands. For his work on femtosecond bunch length measurements he received the outstanding thesis award from the APS Division of Physics of Beams. Following a postdoctoral appointment in LBNL’s chemistry division (studying molecular dynamics), he returned to the BELLA Center in 2009. In 2016 Jeroen received a five-year DOE Early Career Research Program grant, which is funding his current pursuit of laser-plasma accelerator applications towards novel radiation sources.



 

In Memoriam: Max S. Zolotorev, 1941-2020

By Dmitry Budker, Roger W. Falcone, Derek F. Jackson Kimball, Fernando Sannibale, Valeriy V. Yashchuk, and Alexander Zholents

Max Zolotorev

Photo courtesy Felix Izrailev

Retired Berkeley Lab senior scientist Max Samuilovich Zolotorev, a Fellow of the American Physical Society, a pioneer of experimental studies of atomic parity violation, and a generator of ideas across the spectrum of modern physics, passed away on April 1st, 2020 in his home in Eugene, Oregon.

Max was born on October 27, 1941 in Petrovsk, a small town not far from the Russian city of Saratov (on the Volga River), where his mother found herself evacuated from the advancing German army. Max grew up in Kiev, Ukraine. Upon graduating from secondary school, despite showing unusual talent and ability from an early age, since he was Jewish he was not admitted to an institute or even a vocational school. With a friend, he then ventured to Tselina — as part of the Soviet virgin-steppe agricultural development campaign. Upon returning, he worked for about three years at a musical-instrument factory in Kiev, after which, in 1961, he tried his luck in Siberia with the Novosibirsk Electro Technical Institute, where this time he was accepted. After demonstrating outstanding academic performance in his first year, he was able to transfer to the newly founded Novosibirsk State University, from which he graduated in 1966 and assumed a research position at the Institute of Nuclear Physics of the Siberian Branch of the Academy of Sciences of the USSR. There he obtained his first and second doctoral degrees in 1974 and 1979, respectively.

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Max started his career as a particle physicist working on measurements of the hyperon magnetic moments. However, in the early 1970s, following a proposal by theorist Iosif B. Khriplovich (who had been four years ahead of Max in the same elementary school in Kiev, and had the same teacher), Max was drawn into studying fundamental physics using the methods of atomic, molecular, and optical physics. Together with his mentor and colleague Lev M. Barkov, he was the first to discover parity violation in atoms by observing optical rotation of the plane of polarization of light propagating through a bismuth vapor. Atomic parity violation — a consequence of the neutral weak interaction between electrons and nuclei — is a key prediction of the Glashow-Weinberg-Salam electroweak unification theory, the core of what is known today as the standard model of particle physics.

Zolotorev and Barkov’s 1978 measurement came at a crucial time in the history of the standard model. While observations of high-energy neutrino scattering on nuclei at CERN in 1973 provided evidence of neutral weak currents, there was no evidence that the neutral weak current violated parity, as predicted by the Glashow-Weinberg-Salam model, at the time of Zolotorev and Barkov’s experiment. Furthermore, earlier atomic parity violation experiments had produced null results, in contradiction to theoretical predictions. The observation of parity violation in bismuth, followed later by measurements of parity violating electron scattering at SLAC and measurements of atomic parity violation in thallium by Eugene Commins and colleagues at the University of California at Berkeley, was crucial evidence that the Glashow-Weinberg-Salam theory was indeed the correct description of the electroweak interaction.

Max and colleagues also established the foundation for some of today’s most sensitive magnetometers with their measurements in the late 1980s of nonlinear Faraday rotation, clearly identifying the crucial role of quantum coherences.

In 1989, Max and his family emigrated from the USSR and, with support from Max’s friend and future collaborator Eugene Commins, found their way to California (via Austria and Italy). After a brief appointment at UC Berkeley, Max assumed a research position at the Stanford Linear Accelerator Center (SLAC). In 1996, he moved to Berkeley Lab, where he worked in the Accelerator Technology and Applied Physics Division until his retirement in 2018.

Upon arriving at SLAC, Max proposed using lasers for cooling hadrons in colliders (a revolutionary idea for that time) as a variation on van der Meer’s stochastic cooling method. Max was the first to foresee that a laser working in tandem with magnetic undulators would be capable of broadening the bandwidth of van der Meer’s microwave system by a factor of a thousand, correspondingly reducing the cooling time. The “optical stochastic cooling” concept formulated by Max, together with Alexander Mikhailichenko and Alexander Zholents, will soon be put to a test at Fermilab by a group led by Max’s former Novosibirsk University student Valeri Lebedev.

Another of Max’s major inventions (in collaboration with Zholents) is the “slicing method” to produce ultrashort pulses of x-rays, essential for time resolved studies of the properties of condensed matter. In slicing experiments, an ultrashort laser pulse “tags” a portion of an electron bunch circulating in a storage ring, and this results in emission of correspondingly short x-ray pulses when the electrons propagate in a periodic magnetic structure. Joined by Robert Schoenlein and other LBNL colleagues, they were first in the world to obtain ~100 femtosecond x-ray pulses with appreciable intensity. Later on, similar capabilities were developed at x-ray facilities in Germany and Switzerland.

Max was an inspiring mentor and teacher who always set the highest expectations for his students. He taught at Novosibirsk University, and had several research students (including Dmitry Budker). Later on, he played a pivotal role in “bringing up” many of his “scientific grandchildren” (including D. F. Jackson Kimball). While working at SLAC and LBNL, Max actively collaborated with Budker’s group at UC Berkeley (including Valeriy V. Yashchuk) and often visited their lab, typically over the weekend. His teaching and mentoring occurred during these visits. His ability to find “weak spots” in one’s scientific logic was legendary.

ATAP senior scientist Fernando Sannibale describes Max as “a reference standard for me, not only as a scientist but also as a person.” Max was one of those (extremely rare) physicists with extremely broad knowledge comprising pretty much all fields of physics, able to verify, in ten minutes on his office board, if an idea was feasible, and to estimate (within a factor of 2, as he usually remarked) all the consequent results. He did this with warmth and a sense of humor, not only clarifying a physics question, but wrapping it in a joke or a whimsical story.

One particularly memorable dialog between Max and a student started with Max announcing: “Physicists are 3% of rats.” After pondering this for a few moments, the student replied, “Max, what do you mean?” “Look. They did experiment. They put rats in a cage with a high voltage electrode. 27% of rats touch the electrode one time, get shocked, never touch again. 70% of rats watched 27% of rats touch electrode, never touch in first place. But 3% of rats go up to electrode, touch from bottom, get shocked. Then they touch from side, get shocked. Then they touch from other side, get shocked. Then they touch from top, get shocked. They try to figure out what is going on. They are physicist rats.”

One of Max’s great insights was that as physicists, we should never design our experiments around what was sitting in our labs or in our heads. Max would remind us that “We should not be tied to iron!” We should choose deep and important problems, think hard about them, and develop the cleverest way to approach them that we can, learn new subjects, build new apparatus, and push our boundaries and limits as far as we can. Max’s work exemplified the curiosity, creativity, and rigor of physics at its best.

Max Zolotorev is survived by his wife of 55 years Alya, their children Irina and Yakov, and grandchildren Gersh and Giora.



US Plasma Science Strategic Planning Reaches Pivotal Phase

Cover of A Community Plan for Fusion Energy and Discovery Plasma SciencesUS efforts in fusion energy and other aspects of plasma sciences took a key step forward this month with the publication of A Community Plan for Fusion Energy and Discovery Plasma Sciences.

Organized by the American Physical Society’s Division of Plasma Physics, the effort is part of a decadal study, modeled upon the successful community-based consensus-building processes that yielded the 2014 Particle Physics Project Prioritization Panel (“P5”) report for high-energy physics and the 2015 Long-Range Plan for Nuclear Science. The report will serve as input for a subcommittee of the Fusion Energy Sciences Advisory Committee (FESAC) tasked with advising the DOE’s Office of Fusion Energy Sciences.

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ATAP has a long history of diverse R&D in these areas. Four of our people were lead authors of initiatives and white papers that served as input to the process and provided content to the Strategic Plan:

•  Xiaorong Wang, Superconducting Magnet Program, “National Fusion Magnet and Conductor Development Program.”
•  Carl Schroeder, Berkeley Lab Laser Accelerator (BELLA) Center, “Physics and Applications of Ion Acceleration Driven by High-Repetition-Rate PW Lasers.”
•  Peter Seidl, Fusion Science & Ion Beam Technology Program, “Low-Cost, Scalable Power Plants Based on Heavy Ion Fusion.”
•  Jeroen van Tilborg, BELLA Center, “Light sources from Laser-Plasma Accelerators.”

Meanwhile, another consensus study is being conducted by the National Academies: the Decadal Assessment of Plasma Science takes into account fusion and other aspects of plasma science across the Federal agencies. It complements a recent National Academies study that focused on burning plasma research for fusion.



WORKPLACE LIFE

Stay In Touch with Online Seminars

Screen shot of Interdisciplinary Instrumentation Colloquium homepageFeeling a bit disconnected from your colleagues these days? You’re not alone, but dropping on the Lab’s online seminars can help. The ATAP Seminar series has brought Zoom talks by BELLA Center’s Sam Barber, Hai-En Tsai, and Tobias Ostermayr, and Fermilab’s Valeri Lebedev, thus far during April. Late March saw BELLA’s Cameron Geddes present an Interdisciplinary Instrumentation Colloquium, a series held the last Wednesday of the month (next up: Ricky Muller of UC-Berkeley on “Instrumenting the Brain,” April 29).

Employee resources for everything from morning stretches to career development are also available as virtual seminars. To expand your horizons, make new virtual friends, and, as Shelter-in-Place enters its second month, catch glimpses of your colleagues’ quarantine haircuts, add the ATAP and Labwide events calendars to your Google Calendar.

Make Your Online Meetings More Inclusive and Effective

Logo of LBNL's Inclusion, Diversity, Equity, and Accountability OfficeThe social dynamics of online interaction are different, and that includes making everyone feel welcome and valued and getting the most out of your team. The Lab’s Diversity, Equity, and Inclusion office has posted ideas about how to run inclusive and effective virtual meetings. Their recent virtual brown bag seminar on the subject was recorded and is available online.

The Employee Resource Group All Access join forces with the DEI Office for a virtual brown bag on “Remote Meeting Best Practices” at noon Tuesday, April 28. The event will be co-chaired by ATAP Outreach and Education Coordinator Ina Reichel and Facilities Division Senior Electrical Engineer Doug Burkhardt.

Logos of social media platforms

Show The World What Doing Science From Home Looks Like

Are you an adept social-media user? The Laboratory is encouraging staff to use these tools to reach out to the public and explain how science is done at home. Don’t forget to use the hashtags #LBNLwfh and #sciencefromhome.


RECENT PUBLICATIONS AND PRESENTATIONS

Please see the Publications tab of this website for a complete listing.

S. Steinke, J.H. Bin, J. Park, Q. Ji, K. Nakamura, A.J. Gonsalves, S.S. Bulanov, M. Thévenet, C. Toth, J.-L. Vay, C.B. Schroeder, C.G.R. Geddes, E. Esarey, T. Schenkel (LBNL); W.P. Leemans (DESY), “Acceleration of high charge ion beams with achromatic divergence by petawatt laser pulses”, Physical Review Accelerators and Beams 2, 021302 (19 February 2020), https://doi.org/10.1103/PhysRevAccelBeams.23.021302

C. Sun, Ph. Amstutz, T. Hellert, S.C. Leemann, C. Steier, C. Swenson, M. Venturini, “Optimizations of nonlinear kicker injection for synchrotron light sources”, Physical Review Accelerators and Beams 23, 010702 (3 January 2020), https://doi.org/10.1103/PhysRevAccelBeams.23.010702

S.R. Yoffe (Scottish Universities Physics Alliance, University of Strathclyde, and LBNL); R. Lehe (LBNL); B. Ersfeld, E. Brunetti, G. Vieux, A. Noble, B. Eliasson SSUPA, University of Strathclyde); M.S. Hur (UNIST); J.-L. Vay (LBNL); D.A. Jaroszynski (SUPA, University of Strathclyde); “Particle-in-cell simulation of plasma-based amplification using a moving window”, Physical Review Research 2, 013227 (28 February 2020), https://doi.org/10.1103/PhysRevResearch.2.013227

Invited talks without publication opportunity

A. Huebl, “GPU-Powered Particle-in-Cell Community Frameworks for Laser-Plasma Interaction,” Society for Industrial and Applied Mathematics PP20 Exascale Particle Mini-symposium (Seattle, WA, Feb. 12-15, 2020).

R. Lehe, “WarpX: An advanced electromagnetic Particle-in-Cell code,” 2020 DOE Exascale Computing Project Industry Council Deep Dive Workshop (via Zoom, March 10, 2020).

M. Thévenet, “WarpX: Electromagnetic particle-in-cell with adaptive mesh refinement for advanced particle accelerators,” Society for Industrial and Applied Mathematics PP20 Exascale Particle Mini-symposium (Seattle, WA, Feb. 12-15, 2020).


SAFETY: THE BOTTOM LINE

photo illustration of laptop user with wrist pain

[email protected]: Office Work Shouldn’t Hurt

As we settle in for the long haul in a remote workstyle, let’s make sure our ergonomics at home are as sound as our customary set-ups at the Lab.

Most important of all: please do not work directly on your laptop in the long term. An external keyboard, mouse, and monitor, all well positioned on a desk with a good chair, is far more healthy.

Ergonomic assessment is available online, and many ergo accessories can be drop-shipped to your home. (Note: this must be done by Divisional buyers; eBuy items can only be shipped to the Lab, and of course we are trying to avoid unnecessary site visits.)

The Berkeley Lab Ergonomics website has many resources that you can explore, including COVID-specific information, to make your home office safe and comfortable.

After reading all this, do you need to get up and move around? No matter where you are and how you’re equipped, that is a key aspect of being happy and healthy when doing computer work.

Ultraviolet light emitting diode

Consider the source: UV light intense and energetic enough to kill something as small and hardy as a virus can certainly damage living cells; eyes are especially vulnerable

Considering a UV Sanitizer? Select And Use It Safely

As people become worried about contracting the novel coronavirus from contaminated surfaces, sanitizers that use ultraviolet light have spiked in popularity.

These devices, which come in many physical forms, use UV-C radiation to “kill bacteria and viruses, along with just about anything else that is living,” as LLNL’s Sharon Cornelious and LBNL’s Greta Toncheva put it in the latest edition of LLNL’s Laser Safety News Letter (available in versions optimized for screen viewing and for printing).

UV sanitizers are best reserved for special laboratory needs. At home, handwashing with soap and warm water, and avoidance of touching your face unless you know your hands are clean, along with use of ordinary home and office cleaning products in the usual way, will offer safe and effective protection. If you do choose to buy one for home use, please familiarize yourself with its proper usage and safety precautions so that you and your family members (and pets and even houseplants) are protected.

For official use at the Lab, UV generators are subject to our safety rules for non-ionizing radiation. Before buying and using such devices for official purposes, update your Work Planning and Control activity and complete a Hazard Assessment, and ensure that the desired product meets our requirements. Contact Laser Safety Officer Greta Toncheva or Deputy LSO Robert Fairchild when planning your purchase.

Whether the topic is UV sanitizers or other purchases these days, buyer beware! Watch out for products that don’t meet the expected quality and safety standards, especially if the source is unfamiliar or the deal looks too good to be true… and keep an eye on your credit-card statements in search of unexpected charges.

CDC Advice on Prevention: Face Coverings, Social Distance, Handwashing

The virus that causes COVID-19 can spread from a person before they have symptoms. Take action to slow the spread by wearing a cloth face covering in public spaces, keeping at least 6 feet of physical distance, and frequently washing your hands.

For more information, visit cdc.gov/coronavirus

A cloth face covering can be made from items around your home, such as a scarf or cloth napkin. Make sure the covering reaches above your nose and below your chin.

The primary goal is to protect others by keeping your respiratory particles to yourself, in case you are infected (many COVID-19 patients have mild symptoms or none at all, especialy early on).

COVID Oops

Because we could all use a laugh these days…

Social distancing illustrated with alligator and hockey stick

Locally meaningful attempts to help people visualize six feet or two meters of social distance run the gamut from an alligator (Leon County, Florida) to a hockey stick (Canada, eh).

Shutterstock image of VW microbus with surfboard

Might a California equivalent involve the length of a surfboard, or the width of a car? (Why not both?)

MARCH 2020

 

Director’s Corner


At the dawn of a new decade, ATAP and Berkeley Lab look forward to many exciting opportunities. A recent Nature paper by a UK-based international collaboration describes the first-ever demonstration of ionization cooling of muons. The demonstration was made possible by a pair of superconducting spectrometer solenoids designed, built, and delivered by ATAP, the Engineering Division, and an industrial partner.

ATAP researchers (with the Berkeley Accelerator Controls and Instrumentation Program particularly well represented) taught four courses at the Winter 2020 session of US Particle Accelerator School. We have been deeply involved in USPAS since its early days, a key aspect of our investment in the future workforce of the accelerator community. More than 80 people who were, had been, or would become employees of ATAP and its predecessor organizations have taught a total of more than 100 courses and lectures. Many of these courses are team-taught with colleagues from other institutions, forging lasting connections throughout the accelerator community.

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Quantum information science, which holds profoundly transformational potential, is another area where ATAP could make contributions and reap benefits. Quantum innovations have potential to revolutionize networking as well as processing, and Berkeley Lab (headquarters of the Energy Sciences Network) is a stakeholder and innovator in both areas. We recently helped organize DOE’s first Quantum Networking Blueprint Workshop, which drew some 70 participants from national laboratories and universities.

As we write this, back-to-back scientific-community events hosted by LBNL are helping guide the future in two other areas: the Berkeley Lab-headquartered US Magnet Development Program is holding its annual meeting, and many USMDP researchers will stay to participate in the IEEE Low Temperature Superconductor Workshop.

The Advanced Light Source Upgrade Project recently received Critical Decision 3a. This step in the Department of Energy’s project-management process allows Berkeley Lab to get a head start on ALS-U by building a crucial part called the accumulator ring. The ultimate result will be a complete re-envisioning of this high-profile user facility, putting it at the forefront of synchrotron light source performance for another 20 years. The combined expertise of ATAP and the Engineering and ALS Divisions will make this dream a reality, enabling a new generation of discovery science throughout the broad research portfolio of ALS users.

Watch this space in the coming months for more news about these and many more of our efforts, including state-of-the-art accelerator modeling; machine learning and artificial intelligence; laser-plasma acceleration and development of innovative lasers to power it; stronger and better superconducting magnets; and accelerator controls and instrumentation.

All these seemingly disparate elements are actually interrelated, as designing and building state-of-the-art particle accelerators calls for integrating expertise in a wide variety of disciplines. ATAP and our partners throughout the Laboratory (notably the Engineering Division), other institutions, and the private sector can do amazing things together, developing accelerators and putting beams on target for the benefit of the DOE Office of Science portfolio and beyond. With a team poised to build on the past and move into the future, we can make this a decade of marvels throughout the application spaces of particle accelerators.


FEATURED SCIENTIFIC ARTICLES

Demonstration of Ionization Cooling is Breakthrough En Route to Future Muon Collider

—Berkeley Lab researchers contributed major components, analyses to international experiment
Adapted by Glenn Roberts, Jr., of Berkeley Lab Strategic Communications from an original MICE collaboration press release

Click for larger view. (Credit: MICE collaboration)

The international Muon Ionization Cooling Experiment (MICE) collaboration, a U.K.-based effort that includes researchers at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), has made the first-ever demonstration of ionization cooling of muons. This represents a necessary step toward someday being able to build a muon collider, a next-generation facility that could give us a better understanding of the fundamental constituents of matter. Such a future collider would provide at least a 10-fold increase in energy for the creation of new particles compared to the current world leader: the Large Hadron Collider (LHC) at CERN in Europe.

This new research was published in Nature on February 5, 2020.

Until now, the question has been whether you can channel enough muons into a small enough volume to be able to study physics in new, unexplored systems. Muons are in the same class as electrons, but with a mass that is about 200 times larger.

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The results of the experiment, carried out using the MICE muon beamline at the Science and Technology Facilities Council (STFC) ISIS Neutron and Muon Beam facility in the U.K., clearly show that ionization cooling works and can be used to channel muons into a tiny volume.

Muons can also be used as a catalyst for nuclear fusion, and to see through really dense materials that stop X-rays. Researchers hope that the new technique can help produce high-quality muon beams for these applications, too.

“This was an extremely difficult achievement, and crucial to the dream of a muon collider,” said Derun Li, head of the Berkeley Accelerator Controls and Instrumentation Center in Berkeley Lab’s Accelerator Technology and Applied Physics Division.

As manager of Berkeley Lab’s role in the overall Muon Accelerator Program, Li was responsible for delivery of the Lab’s main contribution: two superconducting spectrometer solenoids. These components, which Berkeley Lab researchers designed, built, and delivered, are magnetic coils that measure a property of the muon beam known as emittance (a measure of the orderliness or “coolness”) before and after the cooling channel.

Berkeley Lab researchers also contributed accelerating structures and thermal and mechanical design and analyses.

“Muons combine many of the best advantages of electrons and protons for collider-based particle physics, but also introduce technical challenges,” Li added. Organizing particle beams into bunches that are both tightly packed and orderly, or “cool,” is key to getting the most particle interactions, and therefore the most data, in modern colliders.

Rapid cooling is essential because, unlike the long-lived particles such as electrons or protons that are commonly used in colliders, muons last only a few microseconds.

Li noted that ionization cooling emerged as the only viable technique for muons. “It took a worldwide effort to demonstrate that ionization cooling was possible,” he said, “and it was immensely rewarding to be part of Berkeley Lab’s contributions.”

Since the start of this effort in the early 2000s, Berkeley Lab has been instrumental. The late Berkeley Lab accelerator physicist Michael S. Zisman had championed the push toward future muon colliders, leading the Neutrino Factory and Muon Collider Collaboration and serving as a deputy spokesperson for MICE.

Li noted many important contributions from Berkeley Lab researchers during its 15 years of involvement in the MICE project, including key roles in engineering, magnetics, and cryogenics.

“The enthusiasm, dedication, and hard work of the international collaboration and the outstanding support of laboratory personnel at STFC and from institutes across the world have made this game-changing breakthrough possible,” said MICE spokesperson Ken Long, a professor at Imperial College London.

Photo - Members of the MICE facility team during construction of the experiment at STFC's Rutherford Appleton Laboratory in 2015. (Credit: MICE collaboration)

Members of the MICE facility team during construction of the experiment at STFC’s Rutherford Appleton Laboratory in 2015. (Credit: MICE collaboration)

Chris Rogers, physics coordinator for the collaboration who is based at the ISIS Neutron and Muon Beam facility, explained, “MICE has demonstrated a completely new way of squeezing a particle beam into a smaller volume. This technique is necessary for making a successful muon collider, which could outperform even the LHC.”

Muons are produced by smashing a beam of protons into a target. The muons can then be separated off from the debris created at the target and directed through a series of magnetic lenses. Because of this rough-and-ready production mechanism, these muons form a diffuse cloud, so when it comes to colliding the muons, the chances of them hitting each other and producing interesting physical phenomena is really low.

To make the cloud less diffuse, researchers use a process called beam cooling. This involves getting the muons closer together (even though, having the same electric charge, they repel each other) and moving in the same direction. Magnetic lenses can do either of these things, but not both at the same time.

A major obstacle to cooling a muon beam is that muons only live for 2 millionths of a second, but previous methods developed to cool beams take hours to achieve an effect. In the 1970s a new method, called ionization cooling, had been suggested. The concept was further developed in the 1990s, but testing this idea in practice remained formidable.

MICE experiment, with spectrometers labeled

In this photo of the MICE experiment, superconducting spectrometer solenoids (horizontal cylinders with yellow and black tape) flank the muon ionization cooling channel. A Berkeley Lab team designed, built, and delivered the spectrometer solenoids. (Credit: Steve Virostek/Berkeley Lab)

The MICE Collaboration developed a completely new method to tackle this unique challenge: cooling the muons by putting them through specially designed energy-absorbing materials – such as lithium hydride, a compound of lithium metal and hydrogen, or liquid hydrogen cooled to around minus 418 degrees Fahrenheit – and encased by incredibly thin aluminum windows.

This was done while the beam was very tightly focused by powerful superconducting magnetic lenses. The measurement is so delicate that it requires measuring the beam particle by particle, using particle physics techniques rather than the usual accelerator diagnostics.

After cooling, the muons can be accelerated by a normal particle accelerator in a precise direction. This makes it much more likely the muons will collide. Alternatively, the cold muons can be slowed down so their decay products can be studied.

Professor Alain Blondel, spokesperson of MICE from 2001 to 2013 and emeritus professor at the University of Geneva, said, “We started MICE studies in 2000 with great enthusiasm and a strong team from all continents. It is a great pride to see the demonstration achieved, just at a time when it becomes evident to many new people that we must include muon machines in the future of particle physics.”

“In this era of ever-more-expensive particle accelerators, MICE points the way to a new generation of cost-effective muon colliders,” said Professor Dan Kaplan, Director of the Illinois Institute of Technology Center for Accelerator and Particle Physics in Chicago.

Paul Soler, U.K. principal investigator for MICE and a University of Glasgow professor, said, “Ionization cooling is a game-changer for the future of high-energy muon accelerators such as a muon collider, and we are extremely grateful to all the international funding agencies … and to the staff at the ISIS neutron and muon source for hosting the facility that made this result possible.”

To explore further…



 

CD-3a Approval Is Major Step Toward ALS Upgrade

—Construction of innovative accumulator ring as part of ALS-U project will keep Berkeley Lab at the forefront of synchrotron light source science
From a January 8, 2020 story by Glenn Roberts, Jr., of Berkeley Lab Strategic Communications

Cutaway View of the ALS Showing a Rendering of the ALS Upgrade Project Components

This cutaway rendering of the Advanced Light Source dome shows the layout of three electron-accelerating rings. A new approval step in the ALS Upgrade project will allow the installation of the middle ring, known as the accumulator ring. (Credit: Matthaeus Leitner/Berkeley Lab)

An upgrade of the Advanced Light Source (ALS) at the U.S. Department of Energy’s (DOE’s) Lawrence Berkeley National Laboratory (Berkeley Lab) has passed an important milestone that will help to maintain the ALS’ world-leading capabilities.

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On December 23 the DOE granted approval for a key funding step that will allow the project to start construction on a new inner electron storage ring. Known as an accumulator ring, this inner ring will feed the upgraded facility’s main light-producing storage ring, and is a part of the upgrade project (ALS-U).

This latest approval, known as CD-3a, authorizes an important release of funds that will be used to purchase equipment and formally approves the start of construction on the accumulator ring. This approval is an essential step in a DOE “critical decision” process that involves in-depth reviews at several key project stages.

“It’s exciting to finally be able to start construction and see all our hard work come to fruition and to get one step closer to having a next-generation light source,” said David Robin, director of the ALS-U project.

The ALS produces ultrabright light over a range of wavelengths, from infrared to high-energy X-rays, by accelerating electrons to nearly the speed of light and guiding them along a circular path.

Powerful arrays of magnets bend the beam of electrons, causing it to emit light that is channeled down dozens of beamlines for experiments in a wide range of scientific areas – from physics, medicine, and chemistry to biology and geology. More than 2,000 scientists from around the world conduct experiments at the facility each year.

Brighter, more laser-like beams, and ‘recycled’ electrons

In addition to installing the accumulator ring, the upgrade project will replace the existing main storage ring with a next-generation storage ring that will reduce the size of the light beams at their source from around 100 microns (millionths of a meter) to below 10 microns.

Rendering - This illustration shows components of the accumulator ring (top) and new storage ring (bottom) that will be installed as a part of the ALS-U project. (Credit: Berkeley Lab)

This illustration shows components of the accumulator ring (top) and new storage ring (bottom) that will be installed as a part of the ALS-U project. (Credit: Berkeley Lab)

The combination of the accumulator ring and upgraded main storage ring will enable at least 100 times brighter beams at key energies, and will make the beams more laser-like by enhancing a property known as coherence. This will make it possible to reveal nanometer-scale features of samples, and to observe chemical processes and the function of materials in real time.

Today, electrons at the ALS are first accelerated by a linear (straight) accelerator and a booster ring before they are transferred to the storage ring that feeds light to the beamlines. After the upgrade, electrons from the booster ring will instead go to the accumulator ring, which will reduce the size and spread of the electron beam and accumulate multiple batches or “injections” of electron bunches from the booster ring before transferring bunches to the storage ring.

Shrinking the beam profile in the accumulator ring, together with an innovative technique for swapping electron bunches between ALS rings – and the use of improved magnetic devices called undulators that wiggle the electrons and help to narrow the path of the light they emit – will enable the higher brightness of the upgraded ALS.

Rendering - This rendering shows a sector of accumulator ring equipment along an inner wall at the Advanced Light Source. (Credit: Scott Burns/Berkeley Lab)

This rendering shows a sector of accumulator ring equipment along an inner wall at the Advanced Light Source. (Credit: Scott Burns/Berkeley Lab)

The accumulator ring will also “recycle” incoming electron bunches — via a transfer line from the main storage ring — that have a depleted charge. It will restore them to a higher charge and feed them back into the storage ring.

This electron-bunch recycling, known as “bunch train swap-out,” is a unique design feature of the upgraded ALS that could also prove useful if adopted at other accelerator facilities around the globe. It will reduce the number of lost electrons, in turn reducing the workload for the facility’s production of electrons.

To allow precisely timed electron bunch-train exchanges between the accumulator ring and the booster and storage rings, three transfer lines are needed.

One of these transfer lines will deliver bunches of electrons from the booster ring to the accumulator ring, where the size of the bunches will be reduced and the charge progressively increased, before delivering them via another transfer line to the main storage ring. A third transfer line will allow excess electrons that would otherwise be discarded to reenter the accumulator ring for reuse.

Photo - This silicon-based device is one of eight stages of an inductive voltage adder, which is used to drive a "kicker" that kicks electrons from one path to another. (Credit: Marilyn Sargent/Berkeley Lab)

This silicon-based device is one of eight stages of an inductive voltage adder, which is used to drive a “kicker” that kicks electrons from one path to another. (Credit: Marilyn Sargent/Berkeley Lab)

“Every upgrade project should contribute to accelerator technology and push the field forward in some way,” Robin said. “Recent state-of-the art facilities and upgrades in Europe and the U.S. have implemented technology that we are making use of. Using an accumulator with bunch train swap-out injection is one of our main contributions.”

At the leading edge of ‘soft’ and ‘tender’ X-ray science

Robin credited Christoph Steier, who is the Accelerator Systems Lead for the ALS-U project, and his team for developing the bunch train swap-out technique and related technologies that are critical for the facility’s enhanced performance.

The ALS-U project will keep the facility at the forefront of research using “soft” X-rays, which are well-suited to studies of the chemical, electronic, and magnetic properties of materials. Soft X-rays can be used in studies involving lighter elements like carbon, oxygen, and nitrogen, and have a lower energy than “hard” X-rays that can penetrate deeper into samples.

It will also expand access to “tender” X-rays, which occupy an energy range between hard and soft X-rays and can be useful for studies of earth, environmental, energy, and condensed-matter sciences.

But achieving this performance is a tricky feat, noted Daniela Leitner, who is responsible for accelerator removal and installation for the ALS-U project. The main storage ring is housed in thick concrete tunnels designed to fit one ring, and now the upgrade requires that a second ring be squeezed in.

Click here and use your mouse to navigate the tunnels on a virtual tour of the existing Advanced Light Source storage ring. (Credit: Matterport, Berkeley Lab)

 

Accumulator ring to function as a mini ALS, will boost performance of new storage ring

“We need to build a ‘mini ALS,’” Leitner said, in the form of the accumulator ring. The accumulator ring will measure about 600 feet in circumference while the main storage ring will be about 640 feet in circumference. It must be installed about 6 1/2 feet above the floor — just 7 inches below the ceiling height in some places — and fit snugly around an inner wall to allow workers to safely navigate the ALS’ tunnels.

Robin noted, “This is a complicated logistical ‘dance.’ It is a very confined space, and there is equipment in the existing tunnel that has to be moved to make room.”

Photo - A 3D-printed full-scale model of an accumulator ring component known as a sextupole (left) sits atop a rack. The model and rack helps in planning for the accumulator ring installation. (Credit: Marilyn Sargent/Berkeley Lab)

A 3D-printed full-scale model of an accumulator ring component known as a sextupole (left) sits atop a rack. The metal pipe (middle) stemming from the center of the model represents an electron beam pipe. The model and rack help in planning for the actual accumulator ring assembly and installation. (Credit: Marilyn Sargent/Berkeley Lab)

The accumulator ring is designed to be compact, with a reduced weight, footprint, and power consumption compared to the existing storage ring.

The accumulator ring installation, which is enabled by the CD-3a release of funds, will also be carefully orchestrated to minimize disruptions to ALS operations, with installation work fit into regularly scheduled downtimes over the next few years. The ALS typically runs 24/7 outside of scheduled maintenance downtimes.

The plan is to install and test the accumulator ring prior to a planned yearlong shutdown – with the potential to test the new ring even during regular ALS operations. The shutdown period, known as “dark time,” will allow the removal of the existing storage ring and installation of the new storage ring.

Installing the accumulator ring in advance allows the project team to minimize the shutdown period, which will require the removal and replacement of 400 tons of equipment. This final stage of the project is slated to begin in a few years.

Photo - This powerful magnetic device is a prototype for the seven "main bend" magnets that will be installed in the ALS accumulator ring. The poles are constructed oof precision-machined cobalt-iron. The device weighs 1 ton. (Credit: Marilyn Sargent/Berkeley Lab)

This powerful magnetic device is a prototype for 84 “main bend” magnets that will be installed as a part of the new main storage ring. An additional 24 bend magnets will have a different design. The poles are constructed of precision-machined cobalt-iron. The device weighs 1 ton. (Credit: Marilyn Sargent/Berkeley Lab)

Construction of the accumulator ring will involve bringing about 80 tons of new equipment into the facility. Construction is expected to begin in the summer of 2020. There are dozens of major pieces of equipment to install, including specialized magnetic devices that help to bend and focus the electron beam. These magnetic devices are part of an array of seven pieces that must be installed in each of the 12 ALS sectors and connected by vacuum tubes.

The accumulator ring installation will take an estimated 53,000 worker-hours and requires the placement of thousands of cables.

Prototypes and simulations to ease assembly, installation, troubleshooting

The ALS-U project team has built and acquired prototypes for key components of the accumulator ring, and has constructed models of some of the accumulator ring equipment at their designed height to find the best installation methods. Project crews will also build out fully equipped sections of the accumulator ring to measure their alignment and test the integrated hardware prior to installation to help speed up the process.

Main Bend Magnet Prototyp e

Another view of the main bend magnetic device prototype. (Credit: Marilyn Sargent/Berkeley Lab)

Leitner said that about 80 percent of the installation can be assisted by an overhead crane that will lift heavy equipment into the tunnels, but there are also plans for elevated platforms to ease the installation, and customized lifts to enable installation where the crane cannot be used.

Steier said that technical improvements in accelerator simulations should help to troubleshoot and negate potential problems ahead of time that may arise with the commissioning of the accumulator ring and storage ring. The algorithms account for misaligned magnets and power-supply fluctuations, for example, that are common with constructing large accelerator facilities.

“In general, we simulate everything beforehand, and over time these simulations have become more accurate,” he said, to the point that the simulations can actually guide design choices for the accelerator equipment, and could speed up the ALS-U startup process.

Robin said, “I’m really proud of what the team has accomplished over the last few years.”

The Advanced Light Source is a DOE Office of Science User Facility.

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NEWS IN BRIEF

Man at podium is Paul Dabbar, Under Secretary of Energy for the DOE's Office of Science, gives the welcoming remarks at the Quantum Internet Blueprint Workshop, held Feb. 5-6 in New York City.

Undersecretary Dabbar gives opening remarks

DOE-SC Workshop Begins Mapping the Future of Quantum Communications

From an article by Kathy Kincade, Berkeley Lab Computing Sciences

The U.S. Department of Energy’s Office of Science, under the leadership of Under Secretary of Energy Paul Dabbar, sponsored some 70 representatives from multiple government agencies and universities at the first Quantum Internet Blueprint Workshop, held in New York City Feb. 5-6. The primary goal of the workshop was to begin laying the groundwork for a nationwide entangled quantum Internet.

Building on the efforts of the Chicago Quantum Exchange at the University of Chicago, Argonne and Fermi National Laboratories, and LiQuIDNet (Long Island Quantum Distribution Network) at Brookhaven National Laboratory and Stony Brook University, the event was organized by Brookhaven. ATAP Interim Director Thomas Schenkel was the Lab’s point of contact for the workshop, a co-organizer, and co-chair of the quantum networking control hardware breakout session.

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The technical program committee was co-chaired by Kerstin Kleese Van Dam, director of the Computational Science Initiative at Brookhaven, and Inder Monga, director of ESnet at Lawrence Berkeley National Lab. ESnet’s Michael Blodgett also attended the workshop.

“The dollars we have put into quantum information science have increased by about fivefold over the last three years,” Dabbar told the New York Times on February 10 after the Trump Administration announced a new budget proposal that includes significant funding for quantum information science, including the quantum Internet.

In parallel with the growing interest and investment in creating viable quantum computing technologies, researchers believe that a quantum Internet could have a profound impact on a number of application areas critical to science, national security, and industry. Application areas include upscaling of quantum computing by helping connect distributed quantum computers, quantum sensing through a network of quantum telescopes, quantum metrology, and secure communications.

Toward this end, the workshop explored the specific research and engineering advances needed to build a quantum Internet in the near term, along with what is needed to move from today’s limited local network experiments to a viable, secure quantum Internet.

“This meeting was a great first step in identifying what will be needed to create a quantum Internet,” said Monga, noting that ESnet engineers have been helping Brookhaven and Stony Brook researchers build the fiber infrastructure to test some of the initial devices and techniques that are expected to play a key role in enabling long-distance quantum communications. “The group was very engaged and is looking to define a blueprint. They identified a clear research roadmap with many grand challenges and are cautiously optimistic on the timeframe to accomplish that vision.”


Lab Hosts Back-to-Back Superconducting Magnet Events

US Magnet Development logoThe 2020 general meeting of the US Magnet Development Program was held February 22-24. The LBNL-headquartered, multi-institutional USMDP was founded in 2016 to aggressively pursues the development of superconducting accelerator magnets that operate as closely as possible to the fundamental limits of superconducting materials and at the same time minimize or eliminate magnet “training” — the need to break in a magnet in a series of steps to achieve its design field strength.

The USMDP General Meeting was followed by the IEEE Low Temperature Superconductor Workshop, February 26-28. The 62 registered participants come from DOE, seven US and two international laboratories, 5 universities, and — in an indication of the significance and burgeoning applications of superconductivity — 19 private-sector companies. Fusion energy, high-energy physics, and medical applications such as magnetic resonance imaging are among the user communities represented.

ATAP Instructors Featured at Winter 2020 USPAS

Soren Prestemon with awardOne of the most important venues for workforce development in the accelerator community is the US Particle Accelerator School (USPAS), which offers courses, with the option of credit through university partners, in beam physics and accelerator technology and related topics.

ATAP, almost always represented on the USPAS faculty, played an especially prominent role in the Winter 2020 session, held January 13-24 in San Diego, California. Ten current ATAP employees and one from the Engineering Division were on the instructional teams of four of the graduate-level USPAS courses.

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The courses and instructors were
•    Microwave Measurements and Beam Instrumentation Laboratory: Derun Li, Larry Doolittle, Gang Huang, Tianhuan Luo, Stefano de Santis, Dan Wang
•    Beam Physics with Intense Space Charge: Steve Lund, MSU and USPAS; John Barnard, LLNL; Arun Persaud, LBNL
•    High Brightness Electron Injectors and Applications: Daniele Filippetto and Chad Mitchell, LBNL; Pietro Musumeci, UCLA
•    Magnetic Systems for Accelerators, Detectors, and Insertion Devices: Ross Schlueter, Soren Prestemon, and Diego Arbelaez, LBNL

The ATAP connections don’t stop there. John Barnard, an Acting Associate Program Leader in Lawrence Livermore National Laboratory’s Fusion Energy Sciences Program, was on one of these teams. So was Professor Steve Lund, formerly of LLNL, now with Michigan State University’s National Superconducting Cyclotron Laboratory and also serving as USPAS Director. Both worked closely with us for years in the Heavy Ion Fusion Virtual National Laboratory.

Class photo of Microwave Measurements and Beam Instrumentation Lab, USPAS Winter 2020

ATAP’s Derun Li, Dan Wang, Tianhuan Luo, Gang Huang, and Stefano de Santis, and staff engineer Larry Doolittle, taught the Microwave Measurements and Beam Instrumentation Laboratory

Class photo of Magnet Systems, USPAS Winter 2020

ATAP’s Soren Prestemon and Engineering Division’s Ross Schlueter and Diego Arbelaez taught Magnetic Systems for Accelerators, Detectors, and Insertion Devices

Class picture, Beam Physics with Intense Space Charge, USPAS, Winter 2020

ATAP alumni Steve Lund (now head of the school) and John Barnard joined ATAP staff scientist Arun Persaud to teach Beam Physics with Intense Space Charge

Class photo, High Brightness Injectors and Applications, USPAS Winter 2020

ATAP’s Daniele Filippetto and Chad Mitchell teamed up with Prof. Pietro Musumeci of UCLA to teach High Brightness Electron Injectors and Applications

ATAP’s involvement with USPAS goes back to the early days of the school. Beginning with the symposium-style programs of the 1980s and including the Joint International Accelerator School, more than 80 people who were, had been, or would become employees of ATAP and its predecessor organizations have taught a total of more than 100 courses and lectures. Many of these courses are team-taught with colleagues from other institutions, forging lasting connections throughout the accelerator community.

ATAP staff have taught at CERN Accelerator School sessions as well, most recently including Jean-Luc Vay’s “Modeling and Simulation” lectures in March 2019, and Ji Qiang’s “Monte Carlo Simulation Techniques” and “Multi-Particle Simulation Techniques” in 2018.

Class photo of NE-282 on a tour of the ALS

NE-282 tours the ALS

The University of California-Berkeley campus, adjacent to LBNL, also offers opportunities for education in beam physics, technology, and applications. This semester, ATAP Interim Director Thomas Schenkel and Carl Schroeder, BELLA Center Deputy Director for Theory, are teaching NE-C282, “Beam Physics and Accelerator Technology,” a graduate course in the Department of Nuclear Engineering.

Schenkel and Schroeder had previously taught the course in the Spring 2018 semester. Similar courses had been taught previously by other ATAP staff — most recently by David Robin (now ALS-U Project Director) and Christoph Steier.


 

 

HONORS AND AWARDS

Soren Prestemon and Steve Lund

Prestemon (l.) is given the Iron Man Award by USPAS Director Steve Lund

USPAS Iron Man Award: Soren Prestemon

The USPAS Winter 2020 session brought special recognition for Soren Prestemon, who serves as ATAP’s Deputy Division Director for Technology and heads the LBNL-headquartered US Magnet Development Program and the ATAP-Engineering Berkeley Center for Magnet Technology.

The award “in recognition and appreciation of exceptional contributions in teaching at USPAS sessions” recognizes those who have taught 12 classes. Prestemon is the school’s seventh Iron Man and the third with an ATAP connection.

Cameron Geddes

Cameron Geddes

USPAS Prize: Cameron Geddes

USPAS also recognizes achievement throughout the accelerator community. Cameron Geddes, the Berkeley Lab Laser Accelerator Center’s Deputy Director for Experiments, received the 2019 USPAS Prize for Achievement in Accelerator Science and Technology. Geddes was honored “For pioneering experiments on laser guiding, electron trapping, and high-quality beam production in laser-plasma accelerators.”

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Geddes has led a variety of the Center’s experimental projects, including a new laser facility for one of the many promising near-term applications of laser-plasma accelerators: compact quasi-monoenergetic gamma-ray sources for nuclear nonproliferation and security inspection. He has broad research experience in plasma physics, which at Berkeley Lab has included experimental designs for the PW laser, demonstration of novel concepts in particle injection and beam quality, staging experiments, high energy density science, and large-scale simulations. After working at Lawrence Livermore National Laboratory and Polymath Research on inertial-fusion-related laser-plasma interactions, he earned his doctorate at UC-Berkeley and LBNL in 2005, receiving the Hertz and APS Rosenbluth dissertation prizes. He joined the LBNL staff upon graduation.

Geddes is the seventh person associated with ATAP and its predecessor organizations to receive the USPAS Prize since its inception in 1988.



ICYMI

A recap of recent news, in case you missed it…

Guiding GARD: ATAP Hosts First Strategic-Roadmap Workshop

More GARD Workshop participantsAt the request of the Department of Energy’s Office of High Energy Physics, the accelerator community is developing a Strategic Roadmap for Accelerator and Beam Physics thrust of the HEP General Accelerator R&D (GARD) program. To solicit input to the roadmap, we hosted the first of two preparatory workshops December 9-10, 2019. (The second will be held in the Chicago area in March 2020.)

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The goal of the workshops is to identify the Accelerator and Beam Physics needs that are key to fulfilling OHEP’s GARD mission and to develop a decadal roadmap for thrust activities that OHEP could support.Roomful of GARD Workshop participantsMore GARD Workshop participants

Stakeholders from across the national-laboratory complex participated. The Berkeley Lab workshop was organized into four Working Groups that focused on these topics:

(WG1) Single-particle dynamics, including nonlinearities, and spin dynamics. Conveners: S. Nagaitsev, L. Spentzouris, Y. Cai.
(WG2) High-brightness beam generation (including polarized beams), transport, manipulation and cooling. Conveners: J. Rosenzweig, P. Piot, A. Valishev
(WG3) Mitigation and control of collective phenomena: instabilities, space charge, beam-beam, beam-ion effects, wakefields, and coherent synchrotron radiation. Conveners: J. Power, Z. Huang, S. Cousineau
(WG4) Connections to other GARD roadmaps (cross-cutting WG1-3) [Conveners: J.-L. Vay, M. Conde, M. Hogan]

The upcoming Chicago-area workshop, March 12-13, will emphasize four different topics:
(WG1) Advanced accelerator instrumentation and controls.
(WG2) Modeling and simulation tools (including energy deposition); fundamental theory and applied math.
(WG3) Early conceptual integration and optimization, maturity evaluation
(WG4) Connections to other GARD roadmaps; synergies with non-HEP

Jean-Luc Vay, head of ATAP’s Accelerator Modeling Program, organized the Workshop with the help of the ATAP operations team.


 

OUTREACH AND EDUCATION

Editor’s Note, 12 March:  As part of the Laboratory’s response to COVID-19,  Nuclear Science Day for Scouts and Bring a Kid to Work Day will have to be postponed or cancelled. Please see their respective websites for further guidance.  

Two events that let you have fun while helping to build the scientific workforce of the future are coming up: Nuclear Science Day for Scouts (Saturday, March 21) and Bring a Kid to Work Day (Friday, April 17). Both events are made possible by volunteers who want to share with others what’s so interesting about our work.

Young lady in Scout uniform participates in Nuclear Science Day

A Scout is trustworthy, loyal, etc. — and up to date on the atom

Nuclear Science Day: Saturday, March 21

On Saturday, March 21, the Nuclear Science Division, ATAP, the Advanced Light Source, and the Government and Community Relations Office are co-hosting the Nuclear Science Day for Scouts.

The popular event, now in its 10th year, brings as many as 180-200 Boy and Girl Scouts in grades 8 and above to the Lab as part of earning a nuclear science merit badge.

Volunteers are a key to Nuclear Science Day, assisting with such tasks as registration in the morning, assistance with workshops, a career panel, and chaperoning groups from one activity to the next, where local experts will show them around and answer their questions.

Ina Reichel, youngsters at Daughters and Sons to Work Day

ATAP’s Ina Reichel demonstrates cryogenics

Bring a Kid to Work Day: Friday, April 17

Bring a Kid to Work Day will be held Friday, April 17, 2020. Formerly known as Daughters and Sons to Work Day, it’s a Berkeley Lab tradition that goes back so far, early participants are embarking on their own careers.

Employees’ children aged 9 to 16 are invited to a day of career exploration and fun, with organized activities Labwide (including our famous liquid-nitrogen ice cream). Space is limited to 150 children. We expect registration to open on March 16.

Imitation church sign reading "VOL NTEE S: What's missing?"Bring a Kid to Work Day needs volunteers — not just researchers, but people from all walks of life and all parts of the Lab. Team science takes players at many positions, and kids have a variety of interests. Your dedication to building things or ensuring safety or administering finances could mean you’re just the role model a nascent career needs.

People who would like to help with the liquid nitrogen workshop (the activity that results in ice cream) at Bring a Kid to Work Day should contact ATAP Outreach and Education Coordinator Ina Reichel directly at [email protected] or 510.486-4341.

These are just a few of Berkeley Lab’s opportunities to guide and encourage the generation that will build the future. To learn more, visit the Lab’s K-12 Education site or contact Ina Reichel.


 

WORKPLACE LIFE

Get the Scoop on Carpooling

Illustration showing use of device to arrange carpool

Hoping to scoop up someone to share the ride on your commute? There’s an app for that

Have you thought about carpooling, but don’t know how to find someone whose schedule and start and end locations harmonize with yours today? A new app called Scoop helps match the whereabouts and schedules of co-workers and neighbors for the drive at hand. With its help, we can reduce congestion and our ecological footprint, save money too — and build professional and human connections doing it.

Scoop is designed to be used each morning and evening to meet people for one shared ride. If the people who meet through Scoop have predictable schedules, they may find themselves able to organize a traditional carpool outside the app.

Scoop is just one of many ways in which the Lab is constantly working to make alternatives to the single-passenger car more numerous and attractive.

Visit commute.lbl.gov for the latest information about carpooling, shuttle bus routes, public-transit incentives, bicycling, and telecommuting.


RECENT PUBLICATIONS AND PRESENTATIONS

For a full list, see the Publications tab of this website.

Francis Alexander et al., incl. Jean-Luc Vay (LBNL), “Exascale applications: skin in the game,” Philosophical Transactions of the Royal Society A 378, 20190056 (20 January 2020), http://dx.doi.org/10.1098/rsta.2019.0056

T.G. Blackburn (University of Gothenburg); D. Seipt (University of Michigan); S.S. Bulanov (LBNL); and M. Marklund (University of Gothenburg), “Radiation beaming in the quantum regime,” Physical Review A 101, 012505 (10 January 2020), https://doi.org/10.1103/PhysRevA.101.012505

S.V. Bulanov (Institute of Physics of the ASCR, v.v.i. (FZU), ELI-Beamlines Project; Kansai Photon Science Institute; and Prokhorov General Physics Institute RAS) et al., incl. S.S. Bulanov (LBNL), “Electromagnetic Solitons in Quantum Vacuum,” Phys. Rev. D 101, 016016 (28 January 2020), https://doi.org/10.1103/PhysRevD.101.016016

H. Feng (LBNL and Tsinghua University); S. De Santis, K. Baptiste (LBNL); W. Huang, C. Tang (Tsinghua University); and D. Li (LBNL), “Proposed design and optimization of a higher harmonic cavity for ALS-U,” Review of Scientific Instruments 91, 014712 (30 January 2020); ht

Biaobin Li (National Synchrotron Radiation Laboratory, University of Science and Technology of China, and LBNL) and Ji Qiang (LBNL), “Mitigation of microbunching instability in x-ray free electron laser linacs,” Physical Review Accelerators and Beams 23, 014403 (9 January 2020), https://doi.org/10.1103/PhysRevAccelBeams.23.014403

MICE Collaboration, incl. A. DeMello, S. Gourlay, A. Lambert, D. Li, T. Luo, S. Prestemon, and S. Virostek (LBNL), “Demonstration of cooling by the Muon Ionization Cooling Experiment,” Nature 578 (5 February 2020), pp. 53-9, https://doi.org/10.1038/s41586-020-1958-9
See also the companion News and Views article: Robert D. Ryne (LBNL), “Muon colliders come a step closer,” https://www.nature.com/articles/d41586-020-00212-3

Daniel E. Mittelberger (now at LLNL), Maxence Thévenet, Kei Nakamura, Anthony J. Gonsalves, Carlo Benedetti, Joost Daniels, Sven Steinke, Rémi Lehe, Jean-Luc Vay, Carl B. Schroeder, Eric Esarey, and Wim P. Leemans (now at DESY), “Laser and electron deflection from transverse asymmetries in laser-plasma accelerators,” Physical Review E 100, 063208 (23 December 2019), https://doi.org/10.1103/PhysRevE.100.063208

Ji Qiang, “Advances in global optimization of high brightness beams,” International Journal of Modern Physics A 34 (11 December 2019), 1942016 (16 pages), https://doi.org/10.1142/S0217751X19420168

Ji Qiang, “Emittance growth due to random force error,” Nucl. Instrum. Meth. A 948, 162844 (21 December 2019); https://doi.org/10.1016/j.nima.2019.162844

Invited talks without publication venue
Ji Qiang, “Space-charge effects in high intensity accelerators,” GARD ABP workshop 1 (Berkeley, CA December 9-10, 2019).

 


SAFETY: THE BOTTOM LINE

Calendar image of April 2, circled and with a red pushpin

ATAP, Engineering, ALS-U Safety Day April 2

Editor’s Note, 12 March:  As part of the Laboratory’s response to COVID-19,  the Safety Day scheduled for April 2 has been called off.   

Safety Day is a successful annual tradition in the ATAP and Engineering Divisions and the ALS-U Project that reflects our top priority of safety. This all-hands, all-hazards, all-day event has a mission of “Clean Labs, Clean Shops, Clean Offices,” reflecting its emphasis on good housekeeping and identification of hazards in common areas, offices, labs, and shops.

Chemical stewardship will be a special focus this year, as will on-the-job training.

Detailed instructions, including a list of disposal / recycling locations, self-assessment (QUEST) team assignments and checklists, and management walkaround assignments and checklists, will be posted on the Safety Day web page (coming soon).

Please reserve Thursday, April 2 for this highly beneficial investment in the benefits of a safe and well organized workplace.

Scenes from Safety Day 2019

A morning of hard work by all resulted in the efficiency and sense of pride that comes from clean, well organized workspaces. In the afternoon, QUEST Team inspections and management walkthroughs performed quality-assurance verification of the morning’s successes and gathered the action items that required further work or more resources.

 

A Month of Preparedness

The anniversary of the 1906 San Francisco earthquake (and the comparably devastating fire that ensued) is April 18, so April is Earthquake Preparedness Month. A Labwide earthquake drill on March 31 will kick things off by testing our readiness.

Illustration of how to DROP to the floor, COVER at least your head and neck and preferably find sturdy whole-body refuge, and HOLD on in a quake

In a quake, drop to the floor, protectively cover at least your head and neck (take whole-body cover under something sturdy if available), and hold on

The March 31 drill will also point to things we can improve on Safety Day, such as paying extra attention to things that could fall off shelves and making sure there’s a clear, protected area in your office which to duck, cover, and hold on. It’s also a great time to check and update your “go bag” of emergency supplies.

Our emergency preparedness page has links to a variety of resources to help you prepare before, survive during, and recover after the next earthquake or other emergency.

Lab Alert iconWith all that fresh in our minds, on April 23, a Labwide Safety/Security/Sustainability Fair will be held in the cafeteria parking lot, 11 a.m. – 2 p.m.


DECEMBER 2019

 

Director’s Corner


It’s now been nearly a year since my appointment as Interim Director of ATAP. 2019 started on a high note, with a BELLA Center publication of describing a new energy record for laser-plasma accelerators. Since then we had several very exciting highlights— please see the brief recap in the 2019 In Review article below.

The most recent highlight is a demonstration at Berkeley Lab’s Advanced Light Source of how machine learning using novel software tools that mimic neural networks can predictively feed information forward about beam-size fluctuations and cancel them before they occur. Machine learning and artificial intelligence are a hot topic across many areas of science and we are very happy to see that this new approach has real impact in improving the performance of a workhorse accelerator. Conducted in collaboration with ALS Division staff, the demonstration exemplifies our long tradition of teamwork with the ALS user facility — a tradition that continues to grow with the ALS-Upgrade project (ALS-U).

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Recently, the injector for the Linear Coherent Light Source (LCLS-II) at SLAC completed the formal transition to operations. The source had been developed in collaboration between Berkeley Lab and SLAC

Honors for our employees in 2019 included the election of Ji Qiang as the 29th Fellow of the American Physical Society in our Division’s history; the US Particle Accelerator School Prize for Cameron Geddes; and Berkeley Lab Director’s Awards for Eric Esarey (Scientific Achievement), Ian Pong (Scientific Achievement, Early Career), and Martha Condon (Service).

We communicated our results as lead or co-authors in 26 articles in the refereed literature and another 25 in conference proceedings and other unrefereed publications during fiscal 2019, including 9 articles in Physical Review journals, 4 Physical Review Letters, one in Nature, and a Nature Scientific Reports article. ATAP personnel were on the teaching teams for two US Particle Accelerator School courses and gave three CERN Accelerator School lectures.

Autumn brought us extremes of hot, dry winds and a pair of Public Safety Power Shutdowns by our electric utility. Among the literally hundreds of people who kept us safe and well-informed during these shutdowns of our main site and the methodical re-energization afterward were our Deputy Division Director for Operations, Asmita Patel, and EH&S Coordinator, Pat Thomas. All in all we handled the outages with the cooperation, selflessness, and team spirit that make Berkeley Lab the leader that it is.

I feel honored and humbled to look back on what we accomplished this year, and look forward to moving ahead strongly with new projects and initiatives in 2020.


FEATURED SCIENTIFIC ARTICLE


Machine Learning Helps Stabilize ALS Beams

Courtesy of ALS News, adapted from an article by Glenn Roberts, Jr., of Berkeley Lab Public Affairs

Concentric colorful circles show beam spot size

Profile of the electron beam at the ALS, represented as pixels measured by a charged-coupled device (CCD) sensor.

Researchers at Berkeley Lab’s Advanced Light Source (ALS), a synchrotron-light user facility, have shown that a form of artificial intelligence called “machine learning” can predict noisy fluctuations in the size of beams generated by synchrotron light sources and correct them before they occur. The work solves a decades-old problem and will allow researchers to fully exploit the smaller beams made possible by recent advances in light source technology.

A new approach to an old problem

Many synchrotron facilities deliver light to dozens of beamlines simultaneously. One side effect of this is that the motions of certain insertion devices (IDs) — undulators and wigglers with variable magnetic fields — cause the size of the electron beam to fluctuate, affecting the performance of other beamlines. Typically, corrections for these fluctuations are arrived at through the use of static physics models of the ID magnetic fields and time-consuming calibration measurements. However, with the advent of diffraction-limited storage rings with dramatically smaller beam sizes, much tighter control over beam stability is needed. Demanding experiments require photon-beam stability on time scales ranging from less than seconds to hours to ensure reliable data.

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Here, for the first time, researchers have demonstrated that a neural network (a computerized pattern-recognition algorithm) can learn to predict the beam size during regular operation, given sufficient data about how ID configurations affect the beam. The predictions can then be used to neutralize beam perturbations before they occur (“feed-forward” vs. feedback correction), achieving an order-of-magnitude improvement in stability that fulfills the requirements for future light sources. Their work is described in S.C. Leemann, S. Liu, A. Hexemer, M.A. Marcus, C.N. Melton, H. Nishimura, and C. Sun, “Demonstration of machine learning-based model-independent stabilization of source properties in synchrotron light sources,” Physical Review Letters 123, 194801 (2019).

How to train your synchrotron

Graph showing improvement in vertical beam size due to machine-learning stabilization

Vertical beam size (red) greatly improves when stabilization is on (yellow area). Blue trace is the parameter that is tuned to cancel out fluctuations.

Machine learning fundamentally requires two things: a reproducible problem and huge amounts of data. In this study, researchers fed electron-beam data from the ALS, including the positions of the IDs and the blips in electron-beam performance caused by ID adjustments, into a neural network. The algorithm was then able to learn the complex nonlinear relationships between the ID settings and vertical beam size and make corrections to negate the blips. The vertical beam size was stabilized to within 0.2 µm, or 0.4% of the beam size, compared to 2–3% without correction. The system is also fast: it can make corrections up to 10 times per second, although three times per second appears to be adequate for improving performance at this stage.

One key advantage of this approach is that data acquisition for retraining the neural network can be carried out continuously, even while the feed-forward system is active during a regular user run. Continuous retraining allows the neural network to constantly adapt to a drifting machine and changes in ID configurations during run periods, independent of static physics models.

Future-ready, steady light beams

Because the size of the electron beam mirrors the resulting light beam, this correction scheme also optimizes the light reaching beamline endstations. To demonstrate this, the researchers observed the effects of the algorithm on scanning transmission x-ray microscopy (STXM) images taken at Beamline 5.3.2.2. Highly sensitive to low-frequency variations in light intensity, STXM scans will exhibit banding in response to ID motion elsewhere in the ring. With the neural-network correction on, the bands disappeared.

Figure showing improved stabilization

Banding that appears in STXM images during ID motion (left) disappears after neural-network (NN) stabilization is turned on (right).

Changchun Sun (from left), Hiroshi Nishimura, Simon C. Leemann, C. Nathan Melton, Alex Hexemer, and Y. Lu in the ALS control room. The team successfully demonstrated how machine-learning tools can improve the stability of photon-beam size via adjustments that largely cancel out problematic fluctuations — from a level of a few percent to 0.4 percent, with sub-micron precision.

This enhanced performance is also well suited for advanced x-ray techniques such as ptychography, which can resolve the structure of samples down to the level of nanometers, and x-ray photon correlation spectroscopy (XPCS), which is useful for studying rapid changes in highly concentrated materials that don’t have a uniform structure.

The technique could generally be applied to other light sources and will be especially beneficial for specialized studies enabled by the ALS Upgrade (ALS-U) Project, which will have an even higher demand for consistent, reliable light-beam properties.


ATAP SCIENCE AND TECHNOLOGY IN 2019

In a year that brought strong progress across ATAP’s diverse R&D portfolio, here are some of the highlights.

BELLA Center Sets New Laser-Plasma Accelerator Electron Energy Record

Animation of laser-plasma acceleration February: By accelerating electrons to an energy of 7.8 GeV in just tens of centimeters, BELLA Center researchers have nearly doubled their own previous record for laser-driven particle acceleration, set in 2014 at 4.2 GeV.


Breakthrough in Computational Study of Laser-Plasma Interactions

Computational simulation outputAPRIL: A new 3D particle-in-cell (PIC) simulation tool developed by researchers from Lawrence Berkeley National Laboratory and CEA Saclay is enabling cutting-edge simulations of laser/plasma coupling mechanisms that were previously out of reach of standard PIC codes used in plasma research. More detailed understanding of these mechanisms is critical to the development of ultra-compact particle accelerators and light sources that could solve long-standing challenges in medicine, industry, and fundamental science more efficiently and cost-effectively.

First Electrons from Gun at LCLS-II

Image of LCLS-II gun beamMAY: A new electron gun, designed and built at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) to supply electrons for a next-gen X-ray laser at SLAC National Accelerator Laboratory in Menlo Park, California, fired its first electrons. It is just one of Berkeley Lab’s contributions to the multi-institutional LCLS-II project, which is an upgrade of SLAC’s Linac Coherent Light Source (LCLS) X-ray laser.

Phase Control Innovation Leads to Beam Teamwork

Beams being combinedOCTOBER: A breakthrough in phase control of ultrafast lasers is a milestone for a Berkeley Lab-led effort to develop a high-power laser based on coherently combining many low-power pulses from fiber-optic lasers. This could evolve into a system for powering the next generation of laser-plasma accelerators, such as those of ATAP’s BELLA Center. A milestone in our work last year — coherent temporal beam combining — has now been complemented by an innovative beam control technique that holds the promise of adding coherent spatial combining.


NEWS IN BRIEF

Guiding GARD: ATAP Hosts First Strategic-Roadmap Workshop

At the request of the Department of Energy’s Office of High Energy Physics, the accelerator community is developing a Strategic Roadmap for Accelerator and Beam Physics thrust of the HEP General Accelerator R&D (GARD) program. To solicit input to the roadmap, we hosted the first of two preparatory workshops December 9-10, 2019. (The second will be held in the Chicago area in March 2020.)

The goal of the workshops is to identify the Accelerator and Beam Physics needs that are key to fulfilling OHEP’s GARD mission and to develop a decadal roadmap for thrust activities that OHEP could support.

Roomful of GARD Workshop participants

Stakeholders from across the national-laboratory complex participated

More GARD Workshop participants

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The Berkeley Lab workshop was organized into four Working Groups that focused on these topics:
(WG1) Single-particle dynamics, including nonlinearities, and spin dynamics. Conveners: S. Nagaitsev, L. Spentzouris, Y. Cai.
(WG2) High-brightness beam generation (including polarized beams), transport, manipulation and cooling. Conveners: J. Rosenzweig, P. Piot, A. Valishev
(WG3) Mitigation and control of collective phenomena: instabilities, space charge, beam-beam, beam-ion effects, wakefields, and coherent synchrotron radiation. Conveners: J. Power, Z. Huang, S. Cousineau
(WG4) Connections to other GARD roadmaps (cross-cutting WG1-3) [Conveners: J.-L. Vay, M. Conde, M. Hogan]

The upcoming Chicago-area workshop will emphasize four different topics:
(WG1) Advanced accelerator instrumentation and controls.
(WG2) Modeling and simulation tools (including energy deposition); fundamental theory and applied math.
(WG3) Early conceptual integration and optimization, maturity evaluation
(WG4) Connections to other GARD roadmaps; synergies with non-HEP

Jean-Luc Vay, head of ATAP’s Accelerator Modeling Program, organized the Workshop with the help of the ATAP operations team.

HONORS AND AWARDS


ATAP Staff Recognized With Director’s Awards

Three part picture with, l-r, Eric Esarey, Horst Simon, Ian Pong, James Symons, Thomas Schenkel, and Martha Condon

Left to right: Eric Esarey and Deputy Director for Research Horst Simon; Ian Pong with Associate Laboratory Director for Physical Sciences James Symons; ATAP Interim Division Director Thomas Schenkel and Martha Condon

At the annual Berkeley Lab Director’s Awards ceremony, three ATAP people received the Director’s Award for Exceptional Achievement: Eric Esarey for scientific achievement, Ian Pong for scientific achievement (early career category), and Martha Condon for service.

ATAP Deputy Division Director for Operations Asmita Patel and Environment, Safety, and Health Coordinator Patricia Thomas were members of the teams recognized for shepherding the Lab safely through the two multi-day Public Safety Power Shutdowns this fall.

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Eric Esarey
Eric Esarey, Scientific
“In recognition of outstanding contributions to the science and technology of advanced accelerator concepts, and for his pioneering theoretical research in the physics of laser-plasma accelerators that has helped to enable the success of the BELLA Center.”
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Senior Staff Scientist Eric Esarey, director of ATAP’s Berkeley Lab Laser Accelerator Center (BELLA), was honored in the Scientific category.

His focus is on understanding the fundamental principles of intense laser interactions with beams and plasmas, and on developing practical accelerators and radiation sources that rely on these principles. The laser-plasma accelerator (LPA) work at BELLA is among the most exciting frontiers of accelerator science; with the ability to generate gigavolts-in-centimeters accelerating gradients, LPAs offer the potential to reduce the size of future colliders for high-energy physics by orders of magnitude.

Nearer-term applications for these compact machines are already being explored, including compact accelerators for basic science, medicine, and defense, as well as drivers for future light sources, such as x-ray free-electron lasers.

Eric was one of the principal founders of this world-leading center. One of BELLA’s strengths is its integration of theory and computer modeling with experiment, and Eric has led the understanding of LPA physics and adjacent phenomena.

“We have had a big impact on each other’s careers,” writes Gérard Mourou, 2018 Nobel laureate in physics as co-developer of a revolutionary laser technique called chirped-pulse amplification or CPA. Mourou describes Eric as “a true pioneer in the field of laser-plasma accelerators” and goes on to call him “the world’s leading theorist on intense laser interactions with underdense plasmas {…} responsible for many of the key concepts and developments for laser-plasma accelerators and their applications.”

This expertise has been expressed in more than 220 refereed papers, including some considered landmarks in their field, and more than 100 invited and plenary talks at major international conferences. Eric is serving as general chair of the upcoming LBNL-hosted 2020 Advanced Accelerator Concepts Workshop.

Eric is also known as a mentor of colleagues at all levels from graduate students and postdocs through senior scientific staff. Virtually every member of the BELLA Center since 1998 has benefitted from his guidance, including over two dozen students, several who went on to full-time staff positions here.

Ian Pong

Ian Pong, Scientific (Early Career)
“For technical and managerial excellence in pushing Nb3Sn superconductors and cables toward their performance limits in support of high-energy physics colliders and fusion-energy facilities through the U.S. Magnet Development Program and U.S. High-Luminosity LHC Accelerator Upgrade Project.”

Research scientist Ian Pong was recognized in the Scientific (Early Career) category.

The entire history of particle accelerators has been interwoven with the history of stronger, better, and more cost-effective magnets. Both as a technical expert in designing and applying an advanced superconductor called niobium-three-tin (Nb3Sn) and as a team and collaboration leader, Ian has helped achieve Berkeley Lab and DOE priorities at the frontier of magnet technology.

Among these priorities is the ongoing luminosity upgrade of CERN’s Large Hadron Collider, the first significant use of Nb3Sn in an accelerator. Another is the International Thermonuclear Experimental Reactor (ITER), the fusion-energy community’s flagship project, which will include the largest single Nb3Sn procurement in history.

In addition to his work as the Control Account Manager for Cable Winding and Magnet Testing in the High-Luminosity LHC Accelerator Upgrade Project, Ian represented the Physical Sciences Area — the LBNL associate laboratory directorate that includes the ATAP Division — on the LBNL Project Management Advisory Board.

Not only technical excellence but also interpersonal and leadership skills are crucial for today’s interdisciplinary, multi-institutional, and international team science. In a Critical Decision 2/3b review of the HL-LHC AUP, Ian was singled out for the exemplary quality of his management and delivery of his scope of work, and a reviewer described him as the best example for other subsystem managers.

Ian’s expertise is regularly sought by other institutions, helping maintain LBNL’s leadership as a center for superconducting magnet technology. He has a wide network of collaborators, having co-authored peer-reviewed papers with over 110 colleagues from more than 40 institutes.

Ian has also attracted high quality young researchers to join his team. Serving as both a leader and a role model for younger scientists, he has mentored an entry-level scientist, a postdoctoral fellow, two mechanical technicians, 1 QA/QC technician and 16 students.


Martha Condon, Service
“In honor of exceptional and versatile service to the Laboratory over her four decade career as the lead administrator at the startup of multiple new and ongoing research programs in support of the DOE mission.”

An exemplar among the “hidden figures” who support our scientific excellence, ATAP Division Administrator Martha Condon has had a distinguished 39-year career in administrative support. Her achievements run the gamut from conference planning to property management, publications management, preparation of Building 71 for the BELLA Laser, facilitating complicated subcontracts with multiple institutions and businesses, assisting with the proposal process, and supervising/mentoring administrative staff.

She has supported the Division during several directorship transitions while also managing ongoing routine administrative functions, ensuring stewardship of resources and people. She has also been the startup administrator for multiple program and project launches.

Arranging and running events of all kinds and sizes, from small meetings to conferences, is another highlight among Martha’s diverse talents. Presently she is helping organize the 2020 Advanced Accelerator Concepts Workshop. She has also been an integral part of the logistical, planning, organization, and execution of our Safety Days, helping make them a success that in recent years has been joined and emulated by other Physical Sciences Divisions.

Deeply respected by scientific and operations staff within the Division and collaborating business partners across the laboratory, Martha’s award nomination elicited comments like “a treasure” with “superpowers”; “we just could not have done it without Martha’s tireless persistence and leadership
{…} everything worked without a hitch”; “I can’t begin to estimate the amount of administrative effort she has saved me and the Division staff by proactively solving a problem”; and “I knew we could rely on her for anything.”

Honoring the Unsung Heroes of PSPS Planning and Response
Group picture of PSPS response team

In order to prevent wildfires during extremes of high wind and dry weather, several public safety power shutdowns (PSPSs) were imposed this fall by northern California’s electric utility. Two of these area-wide events affected the main Laboratory site. Powering down a major laboratory with thousands of employees, nearly a hundred buildings, and every kind of complicated technical equipment took planning and methodical work, and a total of hundreds of our colleagues rose to the occasion. Lab Director Mike Witherell, Michael Brandt, Deputy Director, Operations, and Horst Simon, Deputy Director, Research, hosted thank-you events for the PSPS responders and saluted their efforts at the awards ceremony.

ENVIRONMENT, SAFETY, AND HEALTH: THE BOTTOM LINE

Reduce, Re-Use, and Recycle to Keep Science Sustainable

Here at Berkeley Lab we set ambitious goals for our environmental footprint, including recycling whatever we can and sending into the waste stream only what we must. But how are we doing? Sustainable Berkeley Lab recently conducted mini-audits of selected buildings, including ATAP’s Building 71. The results indicate where we are doing well and where we can find opportunities for progress.

Pie charts of waste diversion

This figure summarizes the Building 71 mini-audit results. Click for an interactive version (choose Building 71 from the pulldown menu near its top right corner) and other resources to explore.

Some bright spots: We are great at putting only compostable materials in the compost bins, and at avoiding putting landfill materials into any recycling bins. At 0.8% by weight, we’re about Lab average at putting things that should have been compost into other recycling bins.

The biggest opportunity for improvement: Fully 34.5% by weight of what we send to the landfill (vs. a Lab average of 19%) should have been diverted from the waste stream into either compost or recycling, according to the auditors.

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If it was alive in our lifetime, it can probably be composted

Picture of things that could be composted

Creating a diversion: Food scraps and paper plate, used paper towels (found in Other Recycling and Landfill bins, respectively) should have gone into Compost

One of the most common items we might divert from the landfill stream, according to Sustainable Berkeley Lab’s Brie Fulton, is paper that is food-soiled or otherwise unsuitable for the paper-recycling bins. Our compost ends up in an industrial-scale facility that can handle things your home compost heap couldn’t.

Unfortunately our composting vendor has concluded that they cannot handle plant-oil-based plastics, and of course metal and regular plastics don’t go in the compost, but almost any sort of food scraps or food-related paper goods, including paper cups and plates, are fair game. This will go a long way toward meeting the Lab’s goal of diverting 90% of waste from the landfill.

Clean paper or cardboard should go to their highest and best use via the paper-recycling bin.

Keeping it clean
When it comes to Other Recyclables, Fulton points out the usefulness of making sure our diverted materials can actually be recycled. Rinsing a yogurt cup or other food container before putting it in the recycling bin is an example. Such items don’t need re-use levels of cleanliness, but the less they are contaminated, the more readily they will find a market, and the less processing they will need.

The recyclability of plastics is a complicated issue. Signage at the receptacle, and the Waste Guide, show whether any particular plastic can go in the Other Recyclables bin or must be consigned to the landfill. Plastic films (plastic bags, cling/stretch wrap, candy wrappers, etc.) unfortunately must go into the landfill. (Consider alternatives to using them.) And styrofoam is not practical to recycle in our system (although clean packing peanuts can be re-used, so please put them in the special bin available in most mailrooms).

Meeting sustainability: simple measures with high-multiplier benefits
Meetings, workshops, and other gatherings of people unfamiliar with local customs, or just the locations of recycling bins, are often a low point for our waste-diversion goals. When planning a meeting, please consider talking with the custodians about recycling bins — and just as you might show a safety slide so that people unfamiliar with the area know what to do in an emergency, you might show a recycling slide to encourage attendees to find the right bin. (And please make sure handouts are really needed by your attendees and agenda.)

Is centralizing the key to better recycling?
The individual office trash can is another opportunity to improve our waste-diversion performance. For practical reasons, its contents are generally destined for the waste stream rather sorting, and Fulton has observed that its convenience causes things to end up in the landfill unnecessarily. Consider “kicking the can” and instead taking your items to the appropriate central bins.

Half the contents Fulton finds in under-desk bins are food scraps and soiled paper, both of which can usually be composted. Getting them out of your office and into the central bins also makes your office less attractive to rodents and insect pests (more on this in the article below), so that’s a win-win.

Reduce, re-use, recycle… in that order
The best way to handle waste is to avoid making it in the first place. Can you use the same paper coffee cup all day at a meeting, or perhaps bring a reusable mug? Is a product made of (and packaged in) reusable or easily recyclable materials, rather than single-use material destined for a landfill, competitive in performance and price? Saving the Earth is done with decisions and actions throughout the complete lifecycle of a product.

To learn more…
 • Explore the Sustainable Berkeley Lab website for in-depth information about how each of us can do great research with a lighter ecological footprint, and to learn what our waste-management professionals are doing behind the scenes. The Waste Guide is a great place to start.
 • Sustainability Program Manager Brie Fulton is available to give a talk to your group and to consult on waste prevention and management for both ongoing work and special events.


Putting Out the Unwelcome Mat for Certain Holiday Guests

mouse climbing some computer wiresAt this time of year, mice and rats often try to come indoors. Rodents can leave messes and spread diseases… and they are notorious for gnawing on electrical wiring. Here are some tips on how to be a less inviting holiday host.
 • Keep nonperishable snack foods and earthquake supplies in a closed container they cannot easily gnaw though, not loose in a desk drawer or backpack.
 • Remove any food items at the end of each day, and be sure that your under-desk trash can (if you use one) is free of food scraps.  • Don’t leave perishables in breakroom refrigeraters during the break. Bacteria and mold won’t be taking a holiday!
 • Wipe down desktops, tables, and counter tops after food has been consumed. Mere scraps and crumbs by our standards can be a feast for something the size of a mouse.
 • Let your custodians know if you are planning office parties, so they can promptly remove extra trash.
 • Be sure that the last of the trash bags go to outside dumpsters before a building is left unoccupied over the break.

All of these precautions will also help protect against ants.

If you do see rodents or other pests, contact your Building Manager or the Work Request Center to request Pest Control services.

Do not attempt to clean up dead rodents or droppings. Contact your custodians. They are trained in how to clean up safely.

Let’s Think On Our Feet This Winter


Walk Mindfully, Pocket Your Phone, and Hold the Rail!

As we approach the longest night of the year here in the Northern Hemisphere, with rain often in the picture, leaves on the sidewalks and stairways, and holiday decorations almost within easy reach, this is a crucial time for slip, trip, and fall prevention both at the Lab and at home. Let’s walk (and drive and bike) mindfully, which includes paying attention to the physical world around us rather than the virtual world in handheld devices. Avoid Slips, Trips, Falls poster

Movie courtesy Horst Simon, LBNL Deputy Director for Research, and Sponsor, Berkeley Lab Safety Culture Work Group. Poster by Lucky Cortez, UCSF, formerly of the ATAP Operations Team.

Use handrails on stairways and steep walkways, and clean up slippery spills before others come upon them unawares.

Using ladders properly is important at any time of year. For more information on safe use of ladders and stepstools, contact Alyssa Brand, ext. 7246.

Further tips to keep easily prevented accidents from spoiling the festivities are available from the National Safety Council and the US Fire Administration.

Here’s wishing you and yours a happy holiday season and a safe return in the new year!


OCTOBER 2019

Director’s Corner


The future of many endeavors, including the laser-plasma accelerator work at ATAP’s BELLA Center, requires easier access to higher laser power. One approach, being moved forward by Berkeley Lab and our partners, in collaboration with the University of Michigan and Lawrence Livermore National Laboratory, is combining the low-powered pulses from many inexpensive fiber-optic lasers. Preserving certain key characteristics during the combining process is an important and challenging aspect. Now, thanks to an innovative control and stabilization technique, we have spatially coherent combining, an important complement to their earlier demonstration of temporal coherence.

It is a demonstration of the power not only of lasers, but also of collaboration (with other laboratories and our own Engineering Division), and of maintaining leading-edge capabilities in the many disciplines required for these instruments of discovery.

More …

Further good news comes from different sources of light. The Berkeley Lab injector source for the Linac Coherent Light Source II project at SLAC achieved its formal transition to operations. Meanwhile, a Department of Energy review committee recommended going ahead with Critical Decision 3a for the Advanced Light Source Upgrade. If approved, CD-3a would allow Berkeley Lab to begin procurement of long-lead-time items for the new accumulator ring, helping ensure timely construction of this key part of the nation’s future research infrastructure.

Lawrence’s invention of the cyclotron in the early 1930s proved to be one of the transformative innovations in modern science. Much the same could be said for the workstyle pioneered at his laboratory: a framework for designing, building, and operating these machines of big science with multidisciplinary teams. “Excellence in Accelerators,” a short video by Berkeley Lab Strategic Communications, takes a quick look at this history and at how ATAP is helping to drive the next generation of these engines of discovery.

We hope you’ll think of this video and accompanying story as the school year progresses into the holidays. We’ve all met people, ranging from schoolchildren just catching the science bug to friends and relatives, who wonder what we do; this is a great quick explainer. Other opportunities to reach out to the community, especially the schools, are opening up as well.

Our colleagues in doing these things have received a number of honors recently, including three LBNL Director’s Awards and an election to APS Fellowship.

On a more sobering note: this October brings the 30th anniversary of the Loma Prieta quake. I urge each of you to participate in the Laboratory’s earthquake drill on the morning of October 17, part of the California-wide Great Shakeout. Another quake will occur; we cannot know when or where, but it could be tomorrow, and it could be in a location that will strongly impact the Lab site or the places where we live. Let’s make the most of this opportunity to learn how to “prepare before — survive during — recover after.”

Finally, I’d like to thank everyone in ATAP for their forbearance and perseverance during the recent power interruption at our main site and the ongoing resumption of normal operations. It was a reminder of how the Laboratory’s scientific achievements are made possible by many unsung heroes who keep things running during normal times, and in an event like this, ensure safety and minimize the impact upon the rest of us. Among them were our Deputy Division Director for Operations, Asmita Patel, and EH&S Coordinator, Pat Thomas, who were in the Emergency Operations Center, where key people stayed atop the constantly changing situation and kept everyone informed. All in all we handled the outage with the cooperation, selflessness, and team spirit that make Berkeley Lab what it is.


FEATURED SCIENTIFIC ARTICLES


Phase Control Innovation Leads to Beam Teamwork

Beams being combined

More powerful when working together

A breakthrough in phase control of ultrafast lasers is a milestone for a Berkeley Lab effort to develop a high-power laser based on coherently combining many low-power pulses from fiber-optic lasers. This could evolve into a system for powering the next generation of laser-plasma accelerators, such as those of ATAP’s BELLA Center.

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Lasers have progressed tremendously, but one thing remains the same: their applications always seem to need more power with better control.

As ATAP’s Berkeley Lab Laser Accelerator Center (BELLA) looks beyond its current experiments and toward the next generation of its innovative accelerators, it will need a new generation of lasers. They will have to provide significantly more power in shorter pulses at a much higher repetition rate than today’s.

One promising candidate is based on fiber optics. However, the power that can be extracted from each fiber is quite limited: some 10 millijoules. To use fiber technology for a laser suitable for the next generation of laser-plasma accelerators, dubbed “k-BELLA” for its kilohertz/kilowatt performance class, the beams from many fibers would have to be combined, obtaining joule-class output. For a laser-plasma accelerator, they would also have to be combined coherently in space and time so the results are seen by the laser-plasma accelerator as one powerful laser pulse, not as independent pulses in close proximity.

Coherent beam combining concept could be key to unprecedented beam power

This has been an active area of research here and elsewhere. A milestone in the Berkeley Lab effort last year — coherent temporal beam combining — has now been complemented by an innovative beam control technique that holds the key to adding coherent spatial combining. The effort is being led by Qiang Du of the BACI Program and the Engineering Division. Their results were recently published in the journal Optics Letters.

“We’re adding a second dimension to our capabilities,” said Du. The key innovation was realizing that side beams rejected in the diffractive beam-combining elements contain information on phase errors, and that this information can be fed back to the combiner in a system of reasonable performance and complexity.

The researchers are now scaling from a proof-of-principle experiment involving a few beams to an unprecedented 81 channels. The usable information increases along with the number of channels, allowing scaling to the hundreds of beams for joule-class combined output without slowing down the response time of the feedback loop.

The overall beam-combining effort is performed in close collaboration with the University of Michigan, home of a seminal idea and key expertise for coherent beam combining, and Lawrence Livermore National Laboratory.

To learn more…
Qiang Du, Tong Zhou, Lawrence R. Doolittle, Gang Huang, Derun Li, and Russell Wilcox, “Deterministic stabilization of eight-way 2D diffractive beam combining using pattern recognition,” Optics Letters 44, 18 (15 September 2019), pp. 4554-7 (11 September 2019), https://doi.org/10.1364/OL.44.004554

It is the third in a series of Optics Letters that the Berkeley Lab researchers have published, following Tong Zhou et al., “Two-dimensional combination of eight ultrashort pulsed beams using a diffractive optic pair,” Optics Letters 43, 14 (11 Jule 2018), pp. 3269-72, https://doi.org/10.1364/OL.43.003269, and Tong Zhou et al., “Coherent combination of ultrashort pulse beams using two diffractive optics,” Optics Letters 42, 21 (2 October 2017), pp. 4422-5, https://doi.org/10.1364/OL.42.004422


TTO for LCLS-II Injector Source

Assembling Berkeley Lab injector source for LCLS-II

Based upon materials by Glenn Roberts, Jr., Berkeley Lab Strategic Communications

The Berkeley Lab injector source for Linac Coherent Light Source-II has been formally accepted through a Transition To Operations (TTO) memorandum. The event marks the end of a highly successful multi-year effort to build this extremely challenging part of LCLS-II.

The electron gun fired its first electrons May 29, 2019. Since then, Berkeley Lab personnel have been working with their SLAC counterparts to commission the full injector source, an effort that continues so that it reaches its full performance expectations. The TTO required that it meet a set of threshold parameters en route to the final goals.

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The injector source is the first stage of an accelerator for a next-generation free electron laser. This FEL will produce powerful hard-X-ray beams at a pulse rate 8,000 times faster than the 120 pulses per second typical of the original LCLS.

Building a Better Electron Gun

APEX gun

The successful test of the LCLS-II electron gun marks the culmination of an R&D effort spanning more than a decade at Berkeley Lab.
   The gun’s design was conceived in 2006 by two ATAP researchers: now-retired physicist John W. Staples and senior scientist Fernando Sannibale. The resulting prototype, the Advanced Photoinjector EXperiment, would later become the prototype for the LCLS-II electron gun.
   The development of the APEX prototype gun was led by Sannibale, who now serves as deputy for accelerator operations for Berkeley Lab’s Advanced Light Source (ALS). A multidisciplinary team brought the gun from the drawing board through its testing phase and to its present operational readiness.
   APEX is being used for a spinoff application in high-resolution, ultrafast electron diffraction. Staples is now assisting with conceptual work on a next-generation electron gun proposed by Sannibale and known as APEX-2.
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“This is a critical milestone for LCLS-II, and for the Berkeley Lab team that designed and built the gun and low-energy beam transport for the project,” said John Corlett, who serves as Berkeley Lab’s interim project management officer and has also served as the senior team lead for Berkeley Lab’s contributions to the multi-institutional LCLS-II project.

Other Berkeley Lab contributions include the “undulators” (magnetic insertion devices) at the heart of the FEL, as well as work on the accelerator’s low-level RF control systems.

Making X-rays with electrons

X-ray lasers use pulsed beams of electrons to generate their X-ray light. These beams gain tremendous energy in massive linear particle accelerators and then give some of that energy off in the form of extremely bright X-ray flashes when they fly through special magnets known as undulators.

The injector’s role is to produce an electron beam with high intensity, a small cross-section and minimal divergence, the right pulse rate, and other properties required to achieve the best possible X-ray laser performance.

The electrons fired by the injector come from the electron gun. It consists of a hollow metal cavity where flashes of laser light hit a photocathode that responds by releasing electrons. The cavity is filled with a radiofrequency (RF) field that boosts the energy of the freed electrons and accelerates them in bunches toward the gun’s exit.

Magnets and another RF cavity inside the injector squeeze the electrons into smaller, shorter bunches, and an accelerator section, being installed, will increase the energy of the bunches to allow them to enter the main stretch of the X-ray laser’s linear accelerator. Spanning almost a kilometer in length, this superconducting accelerator will increase the speed of the electron bunches to almost the speed of light.

The million-pulse challenge

The most delicate injector component is the electron gun, and for LCLS-II the technical demands are bigger than ever, said John Schmerge, deputy director of SLAC’s Accelerator Directorate.

“The first generation of LCLS produced 120 X-ray flashes per second, which means the injector laser and RF power only had to operate at that rate,” he said. “LCLS-II, on the other hand, will also have the capability of firing up to a million times per second, so the RF power needs to be switched on all the time and the laser has to work at the much higher rate.”

This creates major challenges in areas that include electron gun cooling and the laser that drives the photocathode, as described in the full story from the July 2019 issue of ATAP News.

“The LCLS-II project got a flying start, profiting from Berkeley Lab’s experience designing and running this unique electron source,” said John Galayda, then leader of the LCLS-II project. (He is now director of a project at Princeton Plasma Physics Laboratory.) “It continues to be a great collaboration that is crucial in building the next-generation X-ray laser.”

NEWS IN BRIEF


DOE Committee Recommends CD-3a for ALS-U

A DOE committee reviewing the ALS-U Project has unanimously recommended that it receive CD-3A status — an important milestone in construction funding. If approved, ALS-U could proceed with $55.2M in long-lead procurements of the “accumulator ring,” a critical component of the enhanced accelerator.

ALS-U replaces the present ALS storage ring with a multibend achromat (outer multicolored circle) and introduces an accumulator ring (inner)

ALS-U, a major upgrade to Berkeley Lab’s Advanced Light Source, has the goal of “diffraction limited” performance, which requires a storage ring and oher accelerator systems at the edge of what is achievable. ATAP will play key roles in the multi-divisional effort, managed from the Laboratory Directorate, to meet these challenges. The ALS-U Project Director, David Robin, and the interim head of the Laboratory’s Project Management Office, John Corlett, were both ATAP program heads before moving on to their present roles.

The committee recommendation comes one year after ALS-U received Critical Decision 1 approval — a milestone in the DOE project management process that signified the beginning of the preliminary design and engineering phase.

VIDEO: Particle Accelerators Drive Decades of Discoveries at Berkeley Lab and Beyond

— Lab’s expertise in accelerator technologies has spiraled out from Ernest Lawrence’s earliest cyclotron to advanced compact accelerators

Accelerators have been at the heart of Berkeley Lab since its inception, and are still a driving force in the Laboratory’s mission and its R&D program. Join us for this short video by Berkeley Lab Strategic Communications, “Excellence in Accelerators,” that takes a quick look at some highlights of this rich history and of what the future may hold.

To Learn More… click here for the accompanying background story

Quantum Information, Accelerators and Fusion at the 63rd IAEA General Meeting

Quantum information systems and their nexus with ion beam technology was the topic of a September 18 side event at the 63rd annual General Meeting of the International Atomic Energy Agency. The meeting was held September 16-20, 2019, in Vienna, Austria. ATAP Interim Director Thomas Schenkel was one of the featured speakers at the side event.

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“Quantum’s ability to process extremely complex information faster and in greater detail than current technology would open the door for more effectively simulating processes such as fusion,” said Schenkel, quoted in an article about the side event by Nicole Jawerth of the IAEA Office of Public Information and Communication.

“These simulations can help scientists test and understand how fusion could work with different conditions and materials,” he added. “This understanding can provide valuable insights into how to engineer and build machines capable of achieving, harnessing and sustaining a fusion reaction — a challenge toward which there has been steady progress internationally.”

HONORS AND AWARDS


ATAP’S Eric Esarey, Ian Pong, Martha Condon To Receive Director’s Awards

At the upcoming annual Berkeley Lab Director’s Awards ceremony, three ATAP people will be recognized with the Director’s Award for Exceptional Achievement: Eric Esarey for scientific achievement, Ian Pong for scientific achievement (early career category), and Martha Condon for service. The ceremony will be livestreamed 3-5 pm Pacific time Friday, November 15.

Eric Esarey
Eric Esarey, Scientific
“In recognition of outstanding contributions to the science and technology of advanced accelerator concepts, and for his pioneering theoretical research in the physics of laser-plasma accelerators that has helped to enable the success of the BELLA Center.”

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Senior Staff Scientist Eric Esarey, director of ATAP’s Berkeley Lab Laser Accelerator Center (BELLA), was honored in the Scientific category.

His focus is on understanding the fundamental principles of intense laser interactions with beams and plasmas, and on developing practical accelerators and radiation sources that rely on these principles. The laser-plasma accelerator (LPA) work at BELLA is among the most exciting frontiers of accelerator science; with the ability to generate gigavolts-in-centimeters accelerating gradients, LPAs offer the potential to reduce the size of future colliders for high-energy physics by orders of magnitude.

Nearer-term applications for these compact machines are already being explored, including compact accelerators for basic science, medicine, and defense, as well as drivers for future light sources, such as x-ray free-electron lasers.

Eric was one of the principal founders of this world-leading center. One of BELLA’s strengths is its integration of theory and computer modeling with experiment, and Eric has led the understanding of LPA physics and adjacent phenomena.

“We have had a big impact on each other’s careers,” writes Gérard Mourou, 2018 Nobel laureate in physics as co-developer of a revolutionary laser technique called chirped-pulse amplification or CPA. Mourou describes Eric as “a true pioneer in the field of laser-plasma accelerators” and goes on to call him “the world’s leading theorist on intense laser interactions with underdense plasmas {…} responsible for many of the key concepts and developments for laser-plasma accelerators and their applications.”

This expertise has been expressed in more than 220 refereed papers, including some considered landmarks in their field, and more than 100 invited and plenary talks at major international conferences. Eric is serving as general chair of the upcoming LBNL-hosted 2020 Advanced Accelerator Concepts Workshop.

Eric is also known as a mentor of colleagues at all levels from graduate students and postdocs through senior scientific staff. Virtually every member of the BELLA Center since 1998 has benefitted from his guidance, including over two dozen students, several who went on to full-time staff positions here.


Ian Pong

Ian Pong, Scientific (Early Career)
“For technical and managerial excellence in pushing Nb3Sn superconductors and cables toward their performance limits in support of high-energy physics colliders and fusion-energy facilities through the U.S. Magnet Development Program and U.S. High-Luminosity LHC Accelerator Upgrade Project.”

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Research scientist Ian Pong was recognized in the Scientific (Early Career) category.

The entire history of particle accelerators has been interwoven with the history of stronger, better, and more cost-effective magnets. Both as a technical expert in designing and applying an advanced superconductor called niobium-three-tin (Nb3Sn) and as a team and collaboration leader, Ian has helped achieve Berkeley Lab and DOE priorities at the frontier of magnet technology.

Among these priorities is the ongoing luminosity upgrade of CERN’s Large Hadron Collider, the first significant use of Nb3Sn in an accelerator. Another is the International Thermonuclear Experimental Reactor (ITER), the fusion-energy community’s flagship project, which will include the largest single Nb3Sn procurement in history.

In addition to his work as the Control Account Manager for Cable Winding and Magnet Testing in the High-Luminosity LHC Accelerator Upgrade Project, Ian represented the Physical Sciences Area — the LBNL associate laboratory directorate that includes the ATAP Division — on the LBNL Project Management Advisory Board.

Not only technical excellence but also interpersonal and leadership skills are crucial for today’s interdisciplinary, multi-institutional, and international team science. In a Critical Decision 2/3b review of the HL-LHC AUP, Ian was singled out for the exemplary quality of his management and delivery of his scope of work, and a reviewer described him as the best example for other subsystem managers.

Ian’s expertise is regularly sought by other institutions, helping maintain LBNL’s leadership as a center for superconducting magnet technology. He has a wide network of collaborators, having co-authored peer-reviewed papers with over 110 colleagues from more than 40 institutes.

Ian has also attracted high quality young researchers to join his team. Serving as both a leader and a role model for younger scientists, he has mentored an entry-level scientist, a postdoctoral fellow, two mechanical technicians, 1 QA/QC technician and 16 students.


Martha Condon, Service
“In honor of exceptional and versatile service to the Laboratory over her four decade career as the lead administrator at the startup of multiple new and ongoing research programs in support of the DOE mission.”

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An exemplar among the “hidden figures” who support our scientific excellence, ATAP Division Administrator Martha Condon has had a distinguished 39-year career in administrative support. Her achievements run the gamut from conference planning to property management, publications management, preparation of Building 71 for the BELLA Laser, facilitating complicated subcontracts with multiple institutions and businesses, assisting with the proposal process, and supervising/mentoring administrative staff.

She has supported the Division during several directorship transitions while also managing ongoing routine administrative functions, ensuring stewardship of resources and people. She has also been the startup administrator for multiple program and project launches.

Arranging and running events of all kinds and sizes, from small meetings to conferences, is another highlight among Martha’s diverse talents. Presently she is helping organize the 2020 Advanced Accelerator Concepts Workshop. She has also been an integral part of the logistical, planning, organization, and execution of our Safety Days, helping make them a success that in recent years has been joined and emulated by other Physical Sciences Divisions.

Deeply respected by scientific and operations staff within the Division and collaborating business partners across the laboratory, Martha’s award nomination elicited comments like “a treasure” with “superpowers”; “we just could not have done it without Martha’s tireless persistence and leadership
{…} everything worked without a hitch”; “I can’t begin to estimate the amount of administrative effort she has saved me and the Division staff by proactively solving a problem”; and “I knew we could rely on her for anything.”


Ji Qiang Named as APS Fellow

Ji Qiang, senior scientist and deputy program head with ATAP's Accelerator Modeling Program, has joined the ranks of Fellows of the American Physical Society “for extensive contributions and leadership in theoretical and computational beam and accelerator physics, and for pioneering application of high-performance computing in the field.”

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After earning his doctorate in 1997 from the University of Illinois at Urbana-Champaign, Ji worked at Los Alamos National Laboratory, then came to Berkeley Lab in 2002. His interests include novel computational methods and advanced multi-physics computer tools for high intensity/high brightness beam dynamics studies; beam dynamics of high brightness electron beams in x-ray FEL light source accelerators; space-charge effects in high-intensity beams; and beam-beam effects in high energy colliders. Ji has proposed new accelerator concepts such as the recirculating superconducting proton linac, a novel two-stage modulation compression scheme to generate short wavelength and multi-color attosecond FEL x-ray radiation, and a method to improve streak camera resolution using the time-dependent RF field.

He joins 28 present and former members of ATAP and its predecessor organizations who have received this honor.

Another researcher identifying primarily with Berkeley Lab, Robert Kaindl of the Materials Sciences Division, also received the distinction this year, as did four scholars with the University of California, Berkeley, three of whom have Laboratory appointments.

OUTREACH AND EDUCATION


K-12 Opportunities Leaf Out This Fall

An important part of Berkeley Lab’s mission involves kindergarten through high school. Opportunities to reach out to the scientists and engineers of tomorrow are coming up in the near future, including TechWomen, Berkeley Lab Speakers, and STEM Night with Scout Leaders.

The Visit the Berkeley Lab K-12 website has in-depth information on these and other opportunities. Ina Reichel, x4341, ATAP Outreach and Education Coordinator, and Faith Dukes, x6378, Berkeley Lab Manager of K-12 STEM Education Programs, would be glad to answer any questions.

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TechWomen and Girl Scouts Day at Berkeley Lab
Saturday, October 26, 2019 8:30 am – 1:00 pm

ATAP’s Patricia Thomas and Diana Amorin demonstrate the spectral properties of light at a Girl Scouts event in San Carlos, CA

Berkeley Lab will be hosting TechWomen mentors and young women from the Girl Scouts of Northern California during a day of Science, Technology, Engineering, and Math (STEM) explorations. Volunteers will be able to learn more about the TechWomen mentoring program from current staff and help with logistics, facilitate hands-on activities, and participate in one-on-one talks with students interested in STEM. The program will be attended by young women in middle school. To volunteer, please complete the Google Form.

Berkeley Lab K-12 Speakers
Are you interested in discussing your research and/or career with students? If so, consider signing up to be on our list of Berkeley Lab Speakers. Throughout the year, students visit the Lab, and many classrooms are in need of your science and engineering expertise. As a side benefit, you’ll become a better science communicator. The K-12 Program staff will work with local schools to identify needs, craft questions that will lead to meaningful engagement, and match speakers with organizations/school groups. Speakers will mostly present here at Berkeley Lab or over video links. To volunteer, sign up via Google Form.


STEM Night with Scout Leaders

As Nuclear Science Day for Scouts prepares for its 10th anniversary, we are planning to invite Girl Scout troop leaders to the Lab for a night of science activities that will help them engage their Scouts (especially those of the East Bay) regarding the importance and opportunity of STEM. This is shaping up as an evening event in January, perhaps 6-8 pm Thursday, January 23rd. A Google Form lets you indicate your interest.


Accelerator is Simulated, Succcess is Real for ATAP Summer Student

Ji Qiang (left), Elaine Jutamulia, and postdoc David Bizzozero discuss a simulation code

ATAP and Berkeley Lab are highly committed to training the scientists of the future, and some show their promise early. Just after finishing her junior year in high school, Elaine Jutamulia spent the summer of 2019 with the Accelerator Modeling Program.

Working with AMP senior scientist Ji Qiang and postdoctoral scholar David Bizzozero, she helped port the IMPACT Suite and BeamBeam3D — popular “codes” or programs in the Berkeley Lab Accelerator Simulation Toolkit (BLAST) — to the distribution and management site GitHub. She also developed Web-based documentation of the structure and function of these codes.

Now a senior at Oakland’s Head-Royce School, Ms. Jutamulia participates in softball and volleyball — and as a sophomore had been on the robotics team. The latest in what seems sure to be a career-long list of achievements: she was among the two dozen Oakland students recently named as National Merit Scholarship semifinalists.


WORKPLACE LIFE


IDEA Brown Bag Discussions Bolster Team Effectiveness

Matt Sakaguchi and Michelle Elrod

Google’s Matt Sakaguchi (l.) and Cal Poly – San Luis Obispo’s Michelle Elrod speak at the Berkeley Lab talk about Project Aristotle

Berkeley Lab’s emphasis on Inclusion, Diversity, Equity, and Accountability (IDEA) is something we can all put to work for more-effective team science. Two series of lunch-hour brown-bag discussions — one for all employees, the other for supervisors and managers — will emphasize the role of IDEA values in making teams stronger and more effective. A key element of team effectiveness — psychological safety — is getting special attention as we begin this journey of personal and professional growth.

Berkeley Lab’s Chief DEI Officer, Lady Idos, is leading these series of IDEA Brown Bag sessions.

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The sessions are safe places to bring questions and feedback on IDEA at the Lab and how we can share the conversation. No reservations are required, and you can join remotely via Zoom. Bring a lunch!


Evidence-Driven Building Blocks of IDEA

The approach stems from a 2012 Google study, Project Aristotle, that looked at the Google teams considered most successful. (This research was shared during a talk at the Lab in June.) Drawing upon their own findings as well as the broader context of teamwork research, Google’s study concluded that successful teams shared these five traits:

•  Psychological Safety — team members feel safe to take risks and be vulnerable in front of one another
•  Dependability — team members get things done on time and meet a high bar for excellence
•  Structure and Clarity — team members have clear roles, plans, and goals
•  Meaning — work is personally important to team members
•  Impact — team members think their work matters and creates change

All ATAP employees are encouraged to watch the YouTube video about Project Aristotle and participate in these brown-bag sessions. IDEA is the right thing to do with respect to our colleagues, and has practical benefits as well. What better way to honor Berkeley Lab’s heritage as the birthplace of team science than learning how to build stronger and more-effective teams?

To Learn More…
•  Visit the Lab’s Diversity, Equity and Inclusion website for a wide variety of resources.
•  Additional resources tailored to the needs of work leads, supervisors and managers are available at IDEAs In Action.
•  Stay tuned for future brown-baggers that will be announced via Elements.
•  This TEDx talk by Amy Edmondson, Novartis Professor of Leadership and Management at Harvard Business School, discusses how to build psychological safety in teams.


ATAP’s Ina Reichel Recognized for ERG Leadership

Ina Reichel

Ina Reichel

At the August meeting of the leadership teams of all Employee Resource Groups (ERGs), the leaders received a Certificate of Appreciation signed by the Lab’s Chief Diversity Equity & Inclusion Officer Lady Idos and by Lab Director Mike Witherell.

Among the recipients were ATAP’s Ina Reichel, together with Sandra Ciocio from the Physics Division, co-chairs of the Policy Subcommittee of the Women Scientists and Engineers Council. Reichel is also serving as interim WSEC Chair, pending election of a new Chair by the members.

To learn more about the WSEC and the other ERGs (and perhaps get involved), visit their pages on the Lab’s IDEA website, diversity.lbl.gov.

Lab’s Spirit of Teamwork Was Beacon in the Darkness During Power Outage

Emergency lights at the Lab’s main substation against the backdrop of a darkened city

With a severe windstorm in the forecast at what is always a dry, high-fire-danger time of year in northern California, Pacific Gas & Electric chose to shut down high-voltage transmission lines serving much of the Bay Area. Fortunately they gave us a day's advance notice of the likelihood, atop existing general awareness of the possibility. Disconnected from the grid for what is believed to be the first time ever, the main Berkeley Lab site was methodically shut down and would remain closed to all but essential personnel for several days. The adjacent University of California campus and surrounding cities were also affected by this wide-area service interruption.

Gracefully handling an unexpected several-day shutdown of a major laboratory is no small feat… and neither is safely re-energizing its nearly 100 individual buildings and the complex technical equipment within them. The response and recovery efforts involved some 300 staffers whose functions and home departments spanned the breadth of the Laboratory.

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At the heart of this team effort was a group of essential personnel who staffed the Emergency Operations Center and put our response plans into action. Here are some scenes from their week of double workdays to keep the Laboratory safe and secure and its more than 4000 employees, students, guest researchers, and facility users well informed.

For more scenes from the Lab’s response, visit “We Went To Work When The Power Went Out,” a photostory by Berkeley Lab Strategic Communications.

They are also running an ongoing series on the unsung heroes of preparation, response and recovery, including Mission Support Officers (one of whom is our own Pat Thomas), and have a video from lights-out through re-energization.


SAFETY: THE BOTTOM LINE


Honoring the Top Achievers of Safety Day

Engineering Division Director Henrik von der Lippe (l.) congratulates Chavez

Thomas Schenkel presents Safety Day team award to team leader Tobias Ostermayr

Tobias Ostermayr (r.) accepts award on behalf of his team from ATAP Interim Director Thomas Schenkel

The success of our annual Safety Day is built on an all-hands effort, but some stand out for exceptional dedication and the quality of their contributions.

This year, to promote ongoing safety-culture awareness, we honored an outstanding individual worker and the top-performing self-assessment team for their Safety Day efforts. Engineering Division machinist Pete Chavez took the “people’s choice” individual award, while team honors went to the assessment team for the BELLA Center hundred-terawatt area.

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Individual award nominations were solicited from all participants as part of a Safety Day follow-up survey. The winning self-assessment team was selected by divisional officials who performed final walkthroughs and received reports from all the teams.


Team Honors: BELLA 100-TW Area Assessment Team

BELLA Workplace Assessment QUEST Team that won the 2019 Safety Day award
Among the 18 Workplace Self-Assessment QUEST Teams, top honors went to the team that inspected BELLA Center’s hundred-terawatt laser area. Shown here are the winners and the Lab officials who honored the occasion at an August 23 ceremony. From left: Engineering Division EH&S Coordinator Marshall Granados; Environment, Safety, and Health Division safety specialist Herb Toor; ATAP Division EH&S Coordinator Pat Thomas; Engineering Division Director Henrik von der Lippe; ATAP Deputy Division Director for Operations Asmita Patel; BELLA postdoctoral researcher Hai-En Tsai; ATAP Interim Division Director Thomas Schenkel; BELLA postdoctoral researcher Jeroen van Tilborg; BELLA Deputy Director Cameron Geddes; BELLA staff scientist Kei Nakamura; BELLA postdoctoral researchers Sam Barber, Tong Zhou, and Tobias Ostermayr (leader of the winning QUEST team); and BELLA graduate student Fumika Isono. Not shown: BELLA research assistants Manfred Ambat and Max Wallace.

Individual Contributor: Pete Chavez

Chavez, in dark blue (second from right), receives award from von der Lippe

A close race for this “people’s choice” honor, bestowed after voting that was part of the post-event survey, went to Engineering Division machinist Pete Chavez. He was praised by fellow Safety Day participants as a “most organized and patient co-worker” who strives to “improve all work areas he occupies” and “perform difficult tasks in a safe manner” — qualities he displays all year, but especially on Safety Day, where he went “above and beyond” to the point of coming back the next day to put the finishing touches on his contributions.

From left to right, Engineering Division Safety Coordinator Marshall Granados, ATAP Division Safety Coordinator Pat Thomas, and ATAP Deputy Division Director for Operations Asmita Patel join Chavez as he receives the Safety Day individual award from Engineering Division Director Henrik von der Lippe.

On the Anniversary of Loma Prieta, Let’s Shake Out Our Quake Preparedness

This month is the 30th anniversary of the Loma Prieta earthquake. On the very date — Thursday, October 17 — the Lab will participate in the Great ShakeOut earthquake drill, beginning at 10:17 a.m.

Editor’s Note: Due to the ongoing efforts to get back up and running after the power outage — and the fortunately mild natural reminder of seismic hazards that we got on October 14 — the Laboratory drill was postponed. Watch Elements for more information.

Beyond the in-the-moment essentials of “duck, cover, and hold on,” it’s a great opportunity to review all our measures to prepare before, survive during, and recover after.

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Earthquakes: Not If — When

The Hayward Fault runs between the Lab and campus (it actually goes through Memorial Stadium). Seismologists estimate that there is more than a 60% chance of a damaging earthquake striking our region in the next 30 years. The Lab takes extensive quake-preparedness measures, and prudent employees may choose to keep individual supplies in their work areas and cars as well as at home.

In the event of a quake, drop, cover, and hold on. When the shaking stops, grab essential personal items and find a safe route to the evacuation area outside your building. Do not re-enter the building until cleared to do so by safety officials. Hazardous conditions might exist, and there could be aftershocks.

Please take a moment to view this new LBNL video about how to prepare for and respond to a real earthquake.

To help you be prepared at work, at home, and in the car, resources are available from the Earthquake Country Alliance (a suggested first thing to read is Putting Down Roots in Earthquake Country, which they repost from the US Geological Survey).

Another useful source of readiness tips for all kinds of disasters and setbacks is 72 Hours, named after the bare minimum amount of time you should be prepared to survive any form of widespread disaster, anywhere, before help arrives — a full week would be even better.

Observing how people coped with the recent precautionary power outage is an excellent guide as well. A way to charge cell phones, a full tank of gas in the car, a stash of nonperishable food and potable water… this is a good basis for any emergency.

Wildlands Fire: Be Aware and Prepared

helicopter over a forest fire

This month also brings another anniversary that needs no reminder to those of us who lived or worked in this area in 1991 (or 1970): the Oakland/Berkeley Hills wildfire.

Although October is the heart of the classic California fire season, Lab Fire Marshall Todd LaBerge, PE, points out that the risk is tantamount to year-round now. LaBerge’s planned talk on October 10 had to be postponed due to the power outage at the main Lab site, but you can watch a video of a recent presentation.

The LBNL site is in a vulnerable area (in 1923, a conflagration swept down what was then an empty hillside where the Lab now stands, and was stopped just short of the campus — not by the puny hand of man so much as by the Diablo winds’ giving way to onshore flow). Many of us also live in or commute through the urban/wildlands interface and have to be aware and prepared for the risk of wildfire.

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Know Where You’ll Be SAFE

SAFE Buildings shown in dark blue offer best wildfire shelter

In a call that experts will make depending on circumstances, our Protective Action in case of wildfire might be to shelter in place (as opposed to a managed zone-by-zone or complete evacuation).

Certain structures (at least one in each zone) have been analyzed and designated as Safety Areas For Emergencies (SAFE) buildings. Shown in blue on this map, they are preferred locations for hunkering down until wildfire danger has passed.


Learn to Prepare and Survive

homewildfire_150x143yIf you live in a vulnerable area, clear defensible space and remove light fuels.

Cal Fire’s Ready, Set Go program is an excellent resource, as is the National Fire Protection Associations Firewise USA. The University of California has peer-reviewed advice on how to design and maintain landscape for greater fire safety.

See also the Association of Bay Area Governments website and the Diablo FireSafe Council.

Be Aware of Food Safety After Extended Power Outage

Even if breakroom refrigerators at the main Laboratory site were cold when you returned after the shutdown, keep in mind that the power was out for days and that the re-energization of the entire Lab site took most of the weekend after main service was restored. Perishable food was likely in the bacterial-growth danger zone for a substantial period.

Treat all perishable food as suspect. Foodsafety.gov, a joint effort by the US Department of Agriculture, Food and Drug Administration, and Centers for Disease Control and Prevention, offers these guidelines for exercising judgment.

If in doubt, throw it out.

Sign Up for LabAlert

Lab Alert iconPrompt, meaningful information is precious in an emergency. Opt in for text messages to your mobile phone at go.lbl.gov/alert.

Something has happened — should you attempt to come to the Lab? You can call, toll free, 1.800.445.5830 (1-800-HILL-830) for information about the status of LBNL, and check status.lbl.gov.