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Recent ATAP News

As accelerator physicists and engineers, we depend on instrumentation and controls as our eyes and hands by proxy: measuring things that we could not see even if it were safe to look; guiding and shaping things that we cannot touch. It all has to work rapidly and precisely without disturbing the exquisite beam properties that the users require.

To further this essential aspect of today’s accelerator facilities and tomorrow’s, we have organized the Berkeley Accelerator Controls and Instrumentation Center (BACI). Our goal is broadly applicable technology development that will benefit many types of machines throughout the DOE complex.

Another important aspect of many current and future projects is also in the news: advanced undulators. Just this week, SLAC received the first industrially produced soft-X-ray undulator modules for LCLS-II. A total of 21 of these LBNL-designed modules will be installed, followed by 32 of their hard-X-ray counterparts, which we are developing in collaboration with Argonne. Looking toward light sources of the future, we recently set a magnetic-field record for superconducting undulators (more about this in future issues). Read on for more details about these exciting areas of progress…


An incubator for concepts and technologies with wide-ranging benefits that serve LBNL, DOE, and beyond

As particle accelerators grow ever more powerful, and the needs of their scientific users become more subtle and precise, their instrumentation and control systems must become ever more sophisticated. Instrumentation is the “eyes and ears” of the control system that uses this input to manipulate the particle beam; the two go together and are often referred to as AC&I. ATAP’s new BACI Center serves as a central resource for expertise in these areas throughout the accelerator community.

BACI focuses on three areas of the accelerator controls and instrumentation field where Berkeley Lab has traditional strengths: advanced RF design and engineering; ultrahigh-precision controls; and high-dynamic-range beam instrumentation.

Many of the solutions to these problems are applicable to various kinds of accelerators of interest to different user communities — rings or linacs, protons/ions or electrons — so agency investments will yield wide-ranging benefits.

“At Berkeley Lab, we have a long tradition of integrating accelerator theory, modeling, experiment and technology development to advance new accelerators,” says Dr. John Byrd, who headed the former Center for Beam Physics and now will lead BACI. “Our goal here is focusing on new AC&I that will benefit the whole accelerator community, rather than being tied to specific projects.”

Projects and facilities have typically been developing their own instrumentation and controls, he explains, and in that world of schedules and deliverables, there are strong drivers to be technically conservative. BACI has more freedom to take risks in the name of advancing the state of the art, hoping to establish a basis of true next-generation AC&I concepts that individual projects can then build upon to meet their needs.

“This is an especially opportune juncture of maturing and emerging enabling technologies for AC&I, present and future projects that require improvements in this area, and the capabilities of Berkeley Lab,” says Fernando Sannibale, head of ATAP’s accelerator physics program for the Advanced Light Source and principal investigator of APEX, the Advanced Photoinjector Experiment, two key BACI efforts.

State-of-the-art AC&I built on deep foundations

BACI emerges from the Center for Beam Physics, which in turn grew from the Exploratory Studies Group under Swapan Chattopadhyay, and whose deepest roots go back to the 1970s and the beam cooling efforts under Glen Lambertson. Over the course of the years it has developed deep expertise in electron and ion acceleration, “RF gymnastics,” and timing, synchronization, and controls distribution, guided by the integration of theoretical, simulation and experimental tools. (The simulation and modeling aspects of the former Center for Beam Physics were organized late last year as the Accelerator Modeling Program.)

“We have established ourselves a partner of choice for many of the most demanding accelerator projects over the past two decades,” says ATAP Director Wim Leemans. The scientists and engineers who are now part of BACI have a record of success that includes the PEP-II B-factory at SLAC; the Spallation Neutron Source at Oak Ridge National Laboratory; LCLS and now LCLS-II at SLAC; and the PIP-II radiofrequency quadrupole linac at Fermilab. This engagement in a wide variety of projects, with partners throughout the DOE research complex and internationally, has developed a broad range of skills in RF, controls, and instrumentation at a wide variety of accelerators. “Now,” adds Leemans, “we’re combining these skills into a unique and cohesive program aligned with the needs of the Office of Science.”

BACI’s three areas of focus were selected because they are built upon existing LBNL expertise — world-leading in many cases — and stand to be of widespread benefit. Watch for more about them, and articles on their achievements, in future issues of this newsletter.

  • Advanced RF Design and Engineering
    • CW normal-conducting cavities and RF structures
    • RF measurement and characterization
    • Beam impedance modeling and measurement
  • Ultrahigh-Precision Controls
    • RF controls
    • Femtosecond synchronization
    • Controls for complex systems
  • High-Dynamic-Range Beam Instrumentation
    • Beam orbit feedback systems
    • Halo measurement and control

Advanced RF Design and Engineering

Radiofrequency (RF) design for accelerating, manipulating, and controlling beams is a longtime area of strength for BACI that integrates accelerator physics and engineering. Over the past three decades we have developed a number of demanding ion-accelerator “front ends,” including units for the Spallation Neutron Source and a recent radiofrequency-quadrupole linac for Fermilab’s PIP-II project.

Montage of BACI hardware
Click for larger version
A selection of RF structures built at Berkeley Lab over the past two decades illustrates capabilities in advanced RF for both electron and proton accelerators. Clockwise from upper left: A schematic of the APEX photocathode RF gun, which was selected as the LCLS-II injector; the PEP-II B-Factory main higher-order-mode-damped RF cavities; the Muon Ionization and Cooling Experiment (MICE) cavity with beryllium window; the Spallation Neutron Source (SNS) RFQ; the Relativistic Heavy Ion Collider (RHIC) Schottky cavity pickups; and the Advanced Light Source (ALS) harmonic cavity.

Studying and mitigating the deleterious effects of beam impedance — interaction of the fields of an intense beam with the vacuum chamber and accelerator components — is another of our longtime strengths.

In recent years Berkeley Lab has developed a unique capability in developing normal-conducting structures for continuous (CW) acceleration, hitherto the province of more-expensive superconducting cavities. Berkeley Lab has also become a leader in the design of broadband RF structures such as kickers for fast beam manipulation (key to upcoming projects such as ALS-U, the Advanced Light Source Upgrade), as well as in ultrafast sources of high-quality electron beams, vital to LCLS-II and already providing a spinoff application in the form of the HiRES tool for ultrafast electron diffraction.

Ultrahigh-Precision Controls

The stability of accelerators is in large part determined by the stability of the electromagnetic fields that accelerate and guide the beam. Berkeley Lab has become a center of excellence in low-level RF controls; building upon success with RF controls on behalf of the Spallation Neutron Source linac at Oak Ridge and then the FERMI@Elettra free-electron laser, we are now leading a multilab effort on this aspect of the LCLS-II project and looking forward to contributing to PIP-II, with its superconducting linac.

Another challenge is the synchronization of accelerators with lasers, which are used in many applications throughout modern accelerator complexes. We have applied our RF control approach to stabilizing mode-locked laser oscillators, a critical technique for a wide variety of accelerator applications, such as photocathode RF guns, laser-based beam diagnostics, and staged laser-plasma acceleration.

An area of special expertise is high-precision fiber-optic distributed timing and synchronization systems that can operate across wide areas. Though the idea had been invented elsewhere, LBNL brought unique innovations and a high degree of development to this system. Its femtoseconds-across-kilometers capability has proved especially useful to LCLS and now LCLS-II.

A spinoff of our expertise is being explored: the use of field-programmable gate arrays to read the outputs of microwave-sensed outputs in quantum computing.

Laser Design and Control

Besides the numerous uses of lasers throughout accelerators, the future is likely to include new paradigms (such as the one being explored by ATAP’s BELLA Center) in which lasers actually power accelerators, setting up the potential gradient that accelerates the beams. These accelerators hold great promise for being much more compact and perhaps ultimately relevant to high-energy-physics colliders. Moving this type of accelerator forward requires great improvement in high-average-power, high-repetition-rate, ultrafast lasers.

BACI and collaborators, including the University of Michigan (where a key coherent beam-combining technique was invented) and Lawrence Livermore National Laboratory, are working on a highly promising set of approaches to these problems by combining pulses and combining the output of many fiber apertures. We intend to integrate this with the temporal combination scheme described above, together with other methods of amplifying ultrashort pulses, to produce useful high-power systems.

pulse stacking layout
Block diagram of laser architecture shows the interrelationships of the concepts we are working to combine in order to achieve stepping-stone and, ultimately, HEP LPA driver levels of performance. (Click for larger version.)

High-Dynamic-Range Beam Instrumentation

Instrumentation serves as the “eyes and ears” of all accelerators and covers a wide variety of technologies, techniques and required resolution and bandwidth. Facilities and laboratories have generally developed custom solutions to their specific instrumentation needs. However, there are several commonalities among facilities that would share benefit from R&D, including real-time beam orbit control and the measurement and control of beam loss.

At Berkeley Lab we have developed world-leading expertise in beam orbit measurement and feedback control in storage rings, particularly low-emittance electron rings, that enables transverse stability of the beam at the level of microns over time periods of days. Two important steps are needed to reach this level of performance: high-fidelity measurement of the beam position using RF beam signals, and a real-time feedback network to distribute the information and apply corrections at a rate of tens of kHz. We operate this system on the Advanced Light Source and maintain an instrumentation laboratory for development and testing of hardware improvements.

High-power proton and ion accelerators of the future — not only the LHC and its coming upgrades, but also neutrino sources, spallation neutron sources, and accelerator-driven waste transmutation systems — will have to pay more attention than ever to “halo” and other losses of their multi-megawatt beams. One particular focus of Berkeley Lab work will be a new ring paradigm, the “integrable nonlinear focusing lattice,” that offers the promise of beam current and intensity substantially beyond what is possible with traditional ring layouts and their highly linear focusing elements. Berkeley Lab’s contributions include particle detector instrumentation, with several groups already performing relevant R&D.

Steps Forward

BACI is off to a running start with existing efforts that include laser pulse combining, AC&I for ALS-U, LLRF and timing distribution for LCLS-II, as well as spinoff applications in quantum-computing readouts and a nascent user facility for ultrafast electron diffraction. Challenging future prospects include the PIP-II project at Fermilab, an electron-ion collider, and a next generation of our own Advanced Photoelectron Experiment. We look forward to serving the needs of the accelerators of tomorrow.


After a story by Glenn Roberts of the Berkeley Lab Public Affairs Office. Photos courtesy SLAC.

SXR modules arrive at SLAC
April 26, 2017: the first two LBNL-designed, commercially produced soft-X-ray undulator segments for LCLS-II arrive.
In the early afternoon of April 26, the first shipment of powerful magnetic devices for a next-generation laser project arrived at National Accelerator Laboratory in California after a nearly 3,000 mile journey from a factory in New York.

Berkeley Lab is overseeing the development and delivery of these devices, known as soft X-ray undulators. They are a key part of LCLS-II, a free-electron laser being built for SLAC by a partnership of SLAC and Berkeley Lab, Fermilab, Jefferson Lab, and Argonne.

The two devices are the first of what will ultimately be a chain of 21 segments making up the complete soft X-ray undulator. They are at the heart of the free-electron laser, as they will cause the high-energy electron beam from a linear accelerator to emit laserlike beams of X-rays.

The soft X-ray undulator units present an impressive combination of brute strength and fine precision. Each weighs about 6.5 tons and is about 11 feet long, with sturdy steel frames that are designed to withstand nearly 7 tons of force to keep the two rows of magnets precisely positioned as they try to repel each other. The distance between the rows can be adjusted within millionths of an inch to tune the properties of the X-ray laser light.

LCLS-II is a major new facility and upgrade to the existing Linac Coherent Light Source, a DOE Office of Science User Facility enabling higher performance, new capabilities, and higher capacity for new experiments. In particular, LCLS-II will provide a continual stream of X-ray pulses that will enable studies at the atomic, molecular, and nano scales, with femtosecond (quadrillionths-of-a-second) time resolution. This knowledge is eagerly sought in fields ranging from biology to materials science.

“The delivery is ahead of schedule and below the baseline budget,” said John Corlett, a physicist who is Berkeley Lab’s senior team leader in the LCLS-II project collaboration.

Corlett added, “This is a major achievement—the culmination of years of work in designing the undulator, qualifying the design, and working with vendors.”

Additionally, Berkeley Lab is overseeing the final design and mass production of a set of 32 hard X-ray undulator segments. The Lab collaborated with Argonne National Laboratory in the design and development of these segments. (“Hard” refers to higher-energy X-rays, and “soft” refers to lower-energy X-rays.) Undulators using permanent magnets were first used for storage ring light sources and are now in use for free-electron lasers. The late Klaus Halbach of Berkeley Lab was a pioneer in developing the permanent-magnet array used in these devices.

Berkeley Lab is also fabricating a unique electron “gun” that kick-starts the rapid-fire electron bunches needed to produce intense electron beams for LCLS-II. The new gun is derived from the Advanced Photoinjector Experiment (APEX) gun, which was successfully developed at Berkeley Lab and is now being used for ultrafast electron experiments.

“We are glad to contribute our expertise to this realization of a unique new tool for science.”
— ATAP Director Wim Leemans

As the electron beams go through the undulators, the alternating magnetic fields inside will cause electrons to wiggle, giving off some of their energy in the form of light. As the beam goes through the long chain of undulator segments, each precisely spaced field adds to its intensity.

The soft X-ray undulator will be capable of producing up to 1 million soft X-ray pulses per second, and the hard X-ray chain can produce X-ray laser pulses that are up to 10,000 times brighter, on average, than those of the existing LCLS.

“Tremendous effort has gone into the design and development of these undulators at Berkeley Lab and across the project collaboration,” said James Symons, associate laboratory director of Physical Sciences at Berkeley Lab. He oversees both the Engineering and the Accelerator Technology and Applied Physics divisions, which worked together to design and prototype the undulators. “We, and the X-ray user community, are looking forward to their installation and to ‘first light’ at LCLS-II.”

Six and a half tons of precision called for special handling from start to end of the 3000-mile trip.
Wim Leemans, Director of Berkeley Lab’s Accelerator Technology and Applied Physics Division, added, “It’s exciting to see the undulators move from the drawing board to the delivery truck after all those years of work. We are glad to contribute our expertise to this realization of a unique new tool for science.”

Berkeley Lab engineer Matthaeus Leitner has key technical and budgetary responsibility for the undulators, while his colleague Steve Virostek plays the same role for the injector system. Other Berkeley Lab contributions to LCLS-II include accelerator physics and technology studies in beam dynamics, free-electron laser design, the low-level radiofrequency system, and the management and integration of cryogenics systems.

John Galayda of SLAC, Director of the LCLS-II project team, said, “The LBNL team’s performance has been crucial to the LCLS-II project’s good progress to date.”

The soft X-ray undulator shipments will continue every six weeks to SLAC from their assembly at a vendor in Buffalo, N.Y. The shipments will wrap up in spring 2018. To prevent damage and misalignment during their coast-to-coast journey, the undulator segments are shipped in a climate-controlled truck that includes a special shock-absorbing frame.

Once delivered to SLAC, the undulator segments must be fine-tuned. “The undulators have been specially designed to allow for very rapid tuning,” said Henrik von der Lippe, Berkeley Lab’s Engineering Division director. “The process will require as little as two days, compared to the two weeks or more needed by earlier undulators.”

Now that the soft-X-ray undulator segments are in production, engineers are conducting magnetic tests on a pre-production version of a hard X-ray undulator segment. These segments will be assembled by vendors in Buffalo, N.Y., and in Los Angeles, and then shipped to Berkeley Lab for tuning before final delivery to SLAC.


ATAP’s Kelly Swanson Steps Up to the Plate for a Grad Slam

 Wim Leemans and Kelly Swanson
ATAP Director Wim Leemans congratulates BELLA student Kelly Swanson after watching her take top honors in the “Grad Slam” semifinals at UC Berkeley
Doctoral research in physics requires a rigorous work ethic and formidable analytical powers — and summarizing it at a scale of less than a minute per year takes presentation skills every bit as strong. ATAP’s Kelly Swanson just proved that she has all these qualities.

Swanson, a doctoral student in the University of California-Berkeley Physics Department and ATAP’s BELLA Center, is the 2017 winner of UCB’s Grad Slam. The event challenges graduate students from each UC campus to explain their research in three minutes, live and onstage along the lines of a poetry or storytelling “slam.” In addition to first prize from the distinguished panel of judges, she won the “People’s Choice” award in an audience vote.

Swanson will go on to compete against peers from the other eight UC campuses in the final round on May 4. Click here to see the full story on the UCB Physics Department website.

The UCB Graduate Division has put the entire Slam online (this link takes you directly to Swanson’s talk, about half an hour into the event).

“I’m proud of what she has accomplished,” said ATAP Director Wim Leemans, who is Swanson’s research advisor. (Prof. Marjorie Shapiro, of the UCB Physics Department and LBNL’s Physics Division, is her faculty advisor.) Dr. Leemans added, “She presented a complicated aspect of what particle physics is all about, why there is a need for innovation, and how the laser plasma accelerator technology we are developing at BELLA Center has the potential to change the way future accelerators will be built — and all that in just three minutes! She did it with lots of energy and charm as well.”

Another LBNL/UCB Physics student, Stephanie Mack, who works at the Lab’s Molecular Foundry, took third place in the field of eight semifinalists representing a variety of graduate disciplines throughout the campus.

The competition helps build skills that will pay off throughout a scientific life. Dr. Fiona Doyle, Dean of the Graduate Division, quoted in an article on the Graduate Division website, praised the “true passion for the research that our students are doing” that came through in their talks, “and also the significant work they put in to distill it to a concise format that could be grasped by everyone in the audience.”

Our congratulations to all the competitors, and best wishes to Kelly in the final round!

ATAP Postdoc Serena Persichelli Wins “Accelerating Diversity Prize” from International Collaboration

Editor’s Note: Dr. Persichelli was recently awarded the “Accelerating Diversity Prize” by the CERN-based Future Circular Collider (FCC) collaboration, which looks toward machines beyond the Large Hadron Collider, and has been invited to participate in the 2017 FCC Week conference. Here she shares her thoughts on being a young woman building a career in a traditionally male-dominated science, technology, engineering, and mathematics [STEM] field. The article reproduced below was published by CERN as “Diversity matters for the FCC collaboration,” 23 February 2017.

Serena Persichelli The Future Circular Collider study, with the generous support of IEEE-CSC, launched a call for applications for the “FCC Accelerating Diversity prize” to encourage scientists representing different areas of diversity to attend the FCC Week 2017 and exploit one of the many research opportunities offered by the FCC study. In this article meet Serena Persichelli, one of the winners of the FCC Diversity prize, who presently works in Lawrence Berkeley National Laboratory (LBL):

I have decided to join the Particle Accelerators field inspired by the idea to be part of world leading science projects designed to be unsurpassed by any currently envisioned technology, such as LHC and FCC. To pursue this interest, I studied Electronics Engineering in the University of Rome La Sapienza. My PhD research project, based on the study of the beam-wall interaction in proton machines, was entirely carried out at CERN, when in 2012 I joined the Hadron Synchrotron Collective effects section (HSC).

I am currently employed at Lawrence Berkeley National Laboratory (LBL), where I am involved in the conceptual design studies for the Advanced Light Source upgrade (ALS-U). I am still collaborating with my home university and CERN in the framework of the FCC studies: in this context I work on the beam-wall interaction in new devices designed for the FCC-ee machine.

I have decided to join the Particle Accelerators field inspired by the idea to be part of world leading science projects designed to be unsurpassed by any currently envisioned technology, such as LHC and FCC. To pursue this interest, I studied Electronics Engineering in the University of Rome La Sapienza. My PhD research project, based on the study of the beam-wall interaction in proton machines, was entirely carried out at CERN, when in 2012 I joined the Hadron Synchrotron Collective effects section (HSC). I am currently employed at Lawrence Berkeley National Laboratory (LBL), where I am involved in the conceptual design studies for the Advanced Light Source upgrade (ALS-U). I am still collaborating with my home university and CERN in the framework of the FCC studies: in this context I work on the beam-wall interaction in new devices designed for the FCC-ee machine.

During the course of my studies, I encountered a number of preconceptions and biases about women in STEM. I realized that biases and negative stereotypes, whether intentional or otherwise, contribute in pushing women out of scientific careers.

I strongly believe that is fundamental to promote diversity and women participation in STEM and engineering programs. Even if the number of young female scientists joining big centres like CERN is increasing every year, there is still not enough diversity inside smaller groups, specially in US Labs.

To positively impact junior female scientists, misconceptions about women in STEM must be eradicated. I think is very important to give women more visibility in their field of expertise, endorsing them to engage in leading and managing roles, promoting their active participation at science conferences and workshops, encouraging them to act as a resource for younger scientists.
    Enhancing women’s authority and influence, putting the accent on their commitment and competence, instead of maintaining outdated patterns of gender roles, is going to inspire the next generations of scientists and, eventually, reduce women’s isolation and help to demolish the barriers between genders.”


On March 29, ATAP and Engineering Division personnel matrixed to ATAP held our first joint Safety Day. Our all-hands, all-hazards, all-day effort made very substantive improvements throughout our area. Workspaces are organized and efficient, desks have earthquake refuge space underneath, and thanks to some intrepid volunteers, even the microwave ovens in the breakrooms are clean!

The qualitative benefits are easy to understand, but as scientists and engineers we yearn for the quantitative. Just a few highlights of the tangible results:

  • 33 obsolete or malfunctioning computers, now being processed out through the property accounting system
  • 13 rolling bins and 3/4 of a dumpster of paper and cardboard
  • 22 hoppers, rolling bins, barrels, and pallets of excess equipment and miscellaneous scrap and salvage
  • 6 hoppers, machine carts, and boxes of e-waste
  • 1 cargo container filled with still-needed items that were not in active use
  • 0 accidents and injuries — the best statistic of all, a testimonial to a good job of using appropriate personal protective equipment and staying within our training and physical capabilities

Here is a detailed statistical summary of our accomplishments (LBNL login required).

After an intense morning of clean-up came an afternoon of safety assurance. Fifteen QUEST teams assessed our workplaces; then 20 senior people performed walkthroughs with the help of 11 locally knowledgeable escorts.

The QUEST teams identified some 200 action items that are being tracked to completion. Further walkthroughs are already in progress to assign and prioritize actions and verify completion.

We look forward to another year of doing great science and engineering with the safety, efficiency, and sense of pride that comes from a tidy and well organized workplace.


leemansinlab_captioned_150x172y Director's Corner: Workshops Guide the Way
Of all the modern ways to figure out what people want and how they can help make it happen, asking them remains one of the most effective — and getting them all in the same room is ideal for synergy and serendipity and iterative idea-development. That’s why meetings and workshops are a key part of how ATAP operates. Recently we have had a multi-laboratory follow-up to one part of DOE Big Ideas Summit, focusing on the big benefits possible with small accelerators; the LBNL-led U.S. Magnet Development Program refined its priorities and directions at its first general meeting; and the Workshop on the Dynamics of Radiation Effects in Materials spotlighted present and emerging ATAP capabilities.

April will bring an international collaboration meeting on the LHC Accelerator R&D Program (LARP) and the LHC Luminosity Upgrade project, efforts in which ATAP and our partners in the Engineering Division play key roles.

Meanwhile, we have been making ongoing critical contributions to the Linac Coherent Light Source-II project at SLAC, and the recently formed LBNL Project Management Advisory Board has given its highest rating to the LBNL LCLS-II team. Our recently formed Accelerator Modeling Program has published a paper describing a better way to cope with space charge in long-term tracking in high-intensity rings. Longtime expertise in our Fusion Energy and Ion Beam Technology Program is being applied to something that most of us in the accelerator community may not think about very often, but which is of the utmost importance to humankind — agriculture — with a noninvasive technique for in situ soil analysis. And LBNL Director Michael Witherell offers an update on the ALS Upgrade project.

BELLAi stacking illus_94x100y CCT two views illus BELLA-i-dynamics_illus_93x100y LCLS-II SXR on truck ROOTS_detail_95x100y symplectic PIC CSimpson_100x100y MagLevTrainDemo_143x100y

I invite you to read on and learn more about these efforts as we move toward the opportunities for progress that 2017 will bring.


ATAP organized three recent events to bring together partners and other stakeholders in some of our key activities: the Workshop on Big Ideas with Small Accelerators; the first general meeting of the U.S. Magnet Development Program; and the Workshop on Dynamics of Radiation Effects in Materials.

Big Ideas from Small Accelerators

— “Bringing the machine to the problem” for diverse societal benefits

On February 2, 2017, 23 people from eight DOE national laboratories, four other research institutions, five universities, and three private-sector companies came to Berkeley to discuss the big things that might be done with small accelerators.

The workshop was a follow-on to one part of DOE’s third annual Big Ideas Summit. Our presentation at the Big Ideas Summit had focused on ways in which smaller, more cost-effective accelerators, including wakefield accelerators — such as the laser-plasma technology being developed at ATAP’s BELLA Center, as well as the superconducting-rf accelerators that have made great strides in recent years — can benefit society by solving some presently difficult problems. This workshop helped “Big Ideas with Small Accelerators” participants plan our next steps and a potential new entry in the ongoing Big Ideas process.

big ideas applications
Click for larger version
Some of the customers, applications, and requirements that have been brought out in the Solving Big Problems with Small Accelerators effort. Potential uses of advanced compact accelerators are numerous and diverse; the workshop discussed everything from inspection of cargo for nuclear materials, to flue-gas scrubbing at power plants, to precision cancer treatment, to something as humble yet important as disinfecting and removing harmful chemicals from wastewater. The potentially transformative aspect is “bringing the machine to the problem” with a level of physical and financial practicality enabled by new and emerging accelerator technologies.

These applications cover a wide range of societal needs and beam parameters. Nuclear security needs compact, high-energy electron accelerators, both for inspection and for replacement of radioactive sources used in industrial radiography. A host of industrial processes need low-energy (but sometimes high-power) electron beams. Highly targeted cancer treatment needs low-energy electron beams from machines compact enough for hospital deployment. And the DOE Office of Science and other discovery-science customers are always looking for high-performance, compact, energetic electron sources, e.g., for producing synchrotron light.

Public, private roles in bringing ideas to fruition

One thing that these diverse machines and applications have in common is the need for continued public investment in R&D to help bridge the gap between their present technology readiness levels and fullfledged readiness for adoption by the private sector. The US has made a considerable investment in bringing these capabilities to their present state. Bringing them to fruition will result in continued US leadership in their enabling technologies and application-specific implementations.

“Getting this technology into the hands of industry could drive profound changes in security, medicine, and industrial applications,” said ATAP Director Wim Leemans. Together with Dr. Stuart Henderson, who was then director of the Advanced Photon Source Upgrade project at Argonne National Laboratory (and has since been named as director of Jefferson Laboratory), Leemans was one of the original Big Ideas presenters and organized the recent follow-up workshop. “These next-generation accelerators, and the technologies that make them possible, are very likely to come full circle and benefit discovery science,” he added.

Next steps
A workshop now in the planning stages will further explore one of the key steps along the way: the need for multi-kW ultrafast laser technology. Laser physicists and engineers the world over are working on a variety of potentially game-changing advancements in the average power, peak power, and wall-plug efficiency of lasers. Laser technology is also the subject of multi-billion-dollar investments overseas, making this a crucial time for ensuring that the US will be the vendor rather than the customer of tomorrow’s leading-edge lasers. The results will be applicable to high-gradient, high-average-power laser plasma accelerators and to direct applications of laser light.

The workshop will evaluate the laser technology options and their technology readiness levels in support of the Big Ideas applications; the laser and optics R&D path and, where it is reasonable to make an estimate at this point, the costs; and how already-emerging partnerships among laboratories, universities, and the private sector can bring the ideas to fruition.

Look for more on these big ideas in future issues of this newsletter as we explore the needs of prospective users and develop the technologies to meet them.

US-MDP Holds First General Meeting

Forty-seven experts on superconducting magnets and materials, representing three US national labs plus CERN and KEK, seven universities, and four private-sector companies, convened in Napa, California February 6-8 for the first general meeting of the recently formed US Magnet Development Program.


Group picture of the first US-MDP meeting

As this was the first meeting of the MDP, the primary purpose was to introduce the program goals, management structure, current status of active projects and discuss future activities and expansion of the program.

The Office of High Energy Physics (HEP) in the DOE Office of Science established the program in response to recommendations from the Particle Physics Project Physics Prioritization Panel (P5) and the Accelerator R&D Subpanel in November 2015. An initial program plan, based on existing funded activities in superconducting magnets and materials, was completed in June 2016.

The 2.5-day meeting showcased the impressive depth and breadth of the US programs and generated numerous lively and fruitful discussions. This first meeting was judged to be an outstanding success, but we have much work to do in order to meet the challenging goals of the program.

To learn more…

Workshop Focuses on Radiation Effects on Materials

— Convergence opportunities for new tools and techniques, software, experiment

The study of radiation effects in materials is important in a variety of application areas and is an example of the synergistic interplay of basic theoretical studies, modeling/simulations, and experiments. One of the most impactful and ambitious application area is future fusion reactors.

BELLA-i dynamics illustration
BELLA-i simulation
Significant advances in our fundamental understanding of radiation effects can be anticipated in the coming years, due to the rapid emergence of a series of pump and probe tools. These will soon enable access to multi-scale dynamics: at time scales ranging from femtoseconds to seconds, and at spatial scales ranging from fractions of a nanometer to microns and millimeters. Such experimental advances promise to deliver data that can benchmark widely used simulation codes for the first time, greatly enhancing the predictive power of computer models.

Participants from 7 DOE national laboratories, 9 US universities, and three international institutions (LAL, GSI-Darmstadt, and the University of Helsinki) convened in Berkeley December 14-16 to discuss these challenges and opportunities.

Among the existing and emergent tools that can be used to study these effects are ATAP’s NDCX-II heavy-ion accelerator facility, the HiRES apparatus for ultrafast electron diffraction, and BELLA-i.

The impact potential of these advances is tremendous and will be crucial to the grand challenges posed by fusion energy, and also has important implications for other aspects of nuclear energy, as well as high-performance accelerators and radiation-hard electronics.

To learn more about the Workshop, download the summary report by the workshop chairs, Thomas Schenkel and Peter Seidl.


— SXR into long-term test; HGVPU into pre-production; LLRF exercised
The SLAC-based multi-laboratory project to build LCLS-II, a next-generation free-electron laser light source, requires the collaborators to meet state-of-the-art challenges in accelerator physics and technology from end to end. LBNL has crucial responsibilities in the project, including two major deliverables: the injector source and the two FEL undulator arrays, one each for hard and soft X rays.

We contribute as well to accelerator physics and technology studies in beam dynamics, FEL design, low-level RF, and management and integration of cryogenics systems. Production is under way in most of our areas of responsibility.

Soft-X-Ray (SXR) Undulator Phases into Production

All work on the pre-production SXR undulator is complete, the unit has been delivered to SLAC for long-term testing, and production is proceeding with vendors. The first article is planned to be delivered to SLAC in March 2017, ahead of the project schedule.

LCLS-II soft-X-ray undulator module on a flatbed truck Left: The SXR pre-production undulator module delivered to SLAC. All production systems were tested on this unit, the final activity being definition of the wiring harness configuration. Right: SXR mechanical systems assemblies in a production line at the vendor, Keller Technology Corporation in Tonawanda, New York. Keller will integrate the magnetic modules, delivered from Vacuumschmelze GmbH & Co. of Hanau, Germany, into the mechanical systems. The completed units are then shipped to SLAC for tuning and calibration before installation in the LCLS undulator hall. sxr undulator module manufacturing

LBNL manages and works closely with the vendors to deliver to the exacting LCLS-II specifications as proven by the pre-production unit performance, including QA oversight and acceptance criteria. Our approach in developing designs and testing prototypes at LBNL, and transferring the technology to industry, is important in providing high-quality product within cost and schedule requirements for the LCLS-II Project.

HGVPU Assembled, Being Readied for Pre-Production Testing

hgvpu assembly The pre-production Horizontal-Gap Vertically Polarized Undulator (HGVPU) module has been assembled at LBNL, and is being prepared for precision CMM measurements of residual deflections when adjusting the gap. Following the mechanical measurements, the unit will be moved to the LBNL undulator measurement facility for magnetic measurements and tuning. Contracts are now in place with vendors for the production of 33 modules for the hard-X-ray beamline.

The HGVPU pre-production unit including magnet modules, strongbacks, drive motors, and spring cages are shown here completed and assembled to the girder in the LBNL assembly shop.

VHF Gun and Low-Energy Beam Transport

ATAP and others at LBNL play a key role in the technically demanding injector for LCLS-II; they are responsible for its design, construction and commissioning.

vhf cavity vacwall plenum VHF cavity vacuum wall plenum (left) and flange (right) prior to welding. VHF Gun cathode component fabrication is near completion in the LBNL machine shops, and the sub-assembly will be electron-beam welded at a vendor in March. vhf cavity vacwall flange

Work is also proceeding with the low-energy beamline components, including preparations for winding the bucking solenoid and the two beamline solenoids. The buncher cavity will be the next major LCLS-II production item to begin machining in the LBNL shops.

Cleanliness Is Next to the Superconducting Linac

Special attention to cleanliness is required in the LCLS-II beamline components and assemblies in order to keep particulates from entering the superconducting cavities, where they can degrade performance of the accelerating fields.

Surface particle counts on sample material coupons have been made and the results will be compared to measurements taken using a portable airborne particle counter with filtered nitrogen blown across the parts. New internal enclosure walls and doors, and new HEPA filters for the LBNL clean room have arrived and will be installed in February and March.

low particulate vacuum valve An example of the precautions that must be taken to keep the LCLS-II superconducting cavities clean is this low-particulate vacuum valve, delivered for the low-energy beamline of the LCLS-II injector source.

A workshop on particle-free cleaning and assembly is being planned for early March, for discussion of procedures to ensure no particles from the injector source can contaminate the LCLS-II superconducting cavities.

Sourcing the RF Power

A contract to design and build the gun’s radiofrequency power amplifier has been awarded to R&K Co. Ltd. of Fuji City, Japan, and a Preliminary Design Review held. LBNL provided the specifications for the amplifier, which will deliver 1.2 kW CW RF power to the gun, and will manage the contract. A team from LBNL visited R&K for two days to discuss design, testing, and delivery details, and to prepare for a Final Design Review to be held in late February.

Low-Level RF Controls Begin Testing and Software Development

LLRF_1024x960y Prototype LLRF systems, developed under LBNL technical leadership by a team that includes Fermilab, Jefferson Lab, and SLAC, have been exercised on the prototype cryomodules under test at Fermilab and JLab. Superconducting cavity field stability is improving and the LLRF team is developing algorithms to actively control the resonant frequency of the cavities. This capability is included in the systems hardware components, and FPGA programming will be developed to implement resonant control in the few tens of hertz range, as indicated by the prototype cryomodule performance.

Shown here is the injector source gun LLRF prototype chassis about to be tested in the development laboratory at LBNL.


Based on an article by Julie Chao of LBNL Public Affairs

ROOTS_detail_250x263yWhen you think of particle accelerators, the “rhizosphere” — the hidden world of plant roots and the soil — is probably not the first thing that comes to mind. But ATAP physicists are parlaying accelerator science into a potentially transformative tool for studying the composition of soil without disturbing it.

Their work is one of a pair of projects awarded to Berkeley Lab by the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E). These innovative projects give nondestructive ways to “see” into the soil. The goal: giving farmers important information with which they can increase crop yields while also promoting carbon storage.

ATAP’s project will develop a new imaging technique based on neutron scattering to measure the distribution of carbon and other elements in the soil.

“An outstanding example of R&D leverage”
— ATAP Director Wim Leemans

“Both technologies could be transformational for agriculture — for quantifying belowground plant traits and where carbon and other elements are distributed — and will enable the next generation of predictive models for agriculture and climate,” said Dr. Eoin Brodie, a microbiologist and deputy director of Berkeley Lab’s Climate & Ecosystem Sciences Division, who is contributing to both projects. “They’re windows into the soil, something that we urgently need.”

Berkeley Lab received these competitive awards from ARPA-E’s Rhizosphere Observations Optimizing Terrestrial Sequestration (ROOTS) program, which seeks to develop crops that take carbon out of the atmosphere and store it in soil—enabling a 50 percent increase in carbon deposition depth and accumulation while also reducing nitrous oxide emissions by 50 percent and increasing water productivity by 25 percent.

Soil carbon deficits are a global phenomenon resulting from many decades of industrial agriculture. Soils have the capacity to store significant quantities of carbon, reducing atmospheric carbon dioxide concentrations while also enhancing soil fertility and water retention.

From neutrons to gamma rays to carbon detection

Using a neutron source and gamma ray detector to measure carbon in the soil
In one of the ARPA-E ROOTS projects, awarded $2.3 million, Drs. Arun Persaud (the principal investigator) and Bernhard Ludewigt, both of who are physicists in ATAP, will build an instrument that uses inelastic neutron scattering to analyze soil chemistry without disturbing the soil. Collaborating on the project will be Drs. Eoin Brodie and Caitlin Pries, both from the Laboratory’s Earth & Environmental Sciences Area.

“The generator will send neutrons into the soil,” Persaud said. “Each neutron can react with atoms in the soil and generate a gamma ray, which we can detect aboveground with a gamma detector. Then we measure the energy of the gamma, and from that you can tell what kind of atom it is; carbon or iron or aluminum, for example.”

“This technology will be able to not only measure how much carbon is in the soil but also do so with spatial resolution of a few centimeters,” said Persaud. What’s more, he adds, this technique can be employed in the field and can measure changes over space and time without disturbing the soil. Standard methods now involve drilling soil cores and doing chemical analyses on them back in the lab, which does not allow for repeat measurements of the same soil and is not practical over large areas.

Persaud. Ludewigt. Brodie, Pries

From left to right: Drs. Persaud, Ludewigt, Brodie, Pries
Persaud and his team at LBNL will work with Adelphi Technology Inc. to develop the neutron generator and associated-particle imaging system. ATAP will integrate the neutron generator, gamma detectors, and data acquisition system, including analysis software and algorithms to identify carbon in soil concentrations. The goal is to develop a mobile instrument that takes in situ measurements in a farmer’s field.

“This technology has its roots in ion accelerator R&D and has many variants and applications, both inside the Lab and in the private sector,” said Thomas Schenkel, ATAP’s program head for fusion science and ion beam technology. ATAP Director Wim Leemans added that it is “an outstanding example of R&D leverage, with important technology spinoff benefits through a cross-divisional partnership at Berkeley Lab to address challenges with very significant societal impact.”

“Aligned with several of Berkeley Lab’s projects as well as the Lab’s Microbes-to-Biomes initiative, these are two key projects in what we hope will eventually be an entire nimble and networked ecosystem sensing system (called EcoSENSE), which can guide agricultural or forestry system management and quantify the impacts of land use, extreme weather, and climate on carbon storage and ecosystem function,” Brodie said.

Added James Symons, Associate Laboratory Director for Physical Sciences, the area of Berkeley Lab that includes ATAP, “This is a potentially transformational project that is really enabled by having cross-disciplinary scientific expertise — in soil biology, soil physics, soil chemistry, geophysics, nuclear physics — all in one location at Berkeley Lab.”


Many simulations in accelerator physics require particles being tracked through a storage ring for many turns. The algorithms used for this need to be symplectic in order to preserve phase space structure.

If an algorithm is not symplectic, small errors can add up, leading to wrong results. This makes tracking space-charge effects in storage rings difficult: Algorithms to calculate space-charge effects usually use the momentum conserved particle-in-cell (PIC) method. Although this method is self-consistent, it is not symplectic, and the requirements of Liouville’s theorem are not satisfied.

ATAP’s Ji Qiang recently suggested a method that mitigates the numerical grid heating (the way small errors add up in PIC codes) and satisfies the symplectic condition. He suggests a two- and three-dimensional symplectic quasi-static multiparticle tracking model for space charge simulations. It starts from the multiparticle Hamiltonian and uses a gridless spectral model to calculate the space-charge forces.

symplecticvsPIC_500x365y Simulation studies for a simple, coasting proton beam have shown that this new method shows much less artificial emittance growth due to numerical errors (which happens with traditional PIC codes). Shown here is four-dimensional emittance growth evolution from this symplectic multiparticle spectral model (red) and from the PIC finite difference model (green).

Running this new model on a single computer increases the required computing time compared to traditional PIC codes. However the method lends itself very well to parallelization on manycore and GPU computers, as it has perfect load balance and regular data structure.

To learn more…
Ji Qiang, “Symplectic multiparticle tracking model for self-consistent space-charge simulation,” Physical Review Accelerators and Beams 20, 014203 (23 January 2017),


From the March 2 edition of Today at Berkeley Lab

In my December column, I mentioned that we had received first-stage approval for the Advanced Light Source Upgrade project, ALS-U. I’d like to take some time now to talk about why ALS-U is the highest priority project of the Lab, and what that means.

One of Berkeley Lab’s national user facilities, the ALS is part of the DOE’s network of synchrotron light sources, and has been a global leader in soft x-ray science for two decades. The ALS facility was built from 1988 to 1993 on the site of E.O. Lawrence’s 184-inch cyclotron, the accelerator he started building at the time of his 1939 Nobel Prize in Physics. Its 40 beamlines provide over 2,300 scientists annually with the x-ray source and advanced instrumentation they need to advance their understanding of chemical processes and new materials. The number of publications describing ALS results has grown linearly since first operation of the facility, and is now nearly 1,000 per year.

With an average annual operating budget of $60 million, the ALS is enormously important to the Lab. The single most important way we connect with the national research enterprise is through our five user facilities, and we take great pride in the unique set of capabilities they represent. The value of ALS to the scientific community is enhanced by its collaborations with NERSC and the Molecular Foundry.

But the ALS cannot maintain its global reputation without significant enhancements, and in 2016, Lab leadership proposed to the DOE that they take advantage of new accelerator technologies that would allow the ALS to produce coherent beams up to 1,000 brighter than are now possible. The upgraded facility will enable new explorations of chemical reactions, battery performance, biological processes and exotic materials. At the heart of the upgrade is an improved electron storage ring that will use powerful, compact magnets arranged in a so-called multibend achromat lattice. For more about this, please visit

This project is the largest undertaken at the Lab in decades. It draws on talent from several divisions, including the ALS, ATAP, Engineering, and Facilities. Roger Falcone will continue to direct the ALS’s scientific program and operations, and I have appointed Dave Robin as the ALS-U project’s permanent director. Dave will report directly to me — you will see this reporting relationship reflected on the Lab’s new organization chart.

ALS-U continues the Lab’s long legacy of building and operating particle accelerators. The soft x-ray capabilities made possible by this upgrade will surpass those at any storage-ring-based light source, either operating or planned, anywhere in the world. This is a tremendously exciting time for the Lab; please join me in supporting Dave, Roger, and all the people at the Lab developing the upgraded ALS facility that will produce breakthrough science for another 25 years.


Daughters and Sons to Work Day, Nuclear Science Day for Scouts Highlight Upcoming Outreach Opportunities

In April there will be two large outreach events that are only possible thanks to many Lab volunteers lending a helping hand: Daughters & Sons to Work Day (April 27) and Nuclear Science Day for Scouts (April 29). Scientists, engineers, and support staff of all disciplines are invited, so mark your calendars and help build the people who will build the future!

Maglev model train is a perennial favorite among the interactive demos

Thursday April 27th: Daughters and Sons to Work Day

As she does every year, ATAP Education and Outreach Coordinator Ina Reichel runs the popular liquid nitrogen workshop for 9-12-year-olds, one of the Lab’s variety of programs for different age groups.

How You Can Participate
Dr. Reichel likes to teach three 75-minute workshops, but that’s only possible if there are a number of other adults in the room to help with handing out materials and making sure everyone stays safe. Cryogen Safety (EHS0170, an online course that takes about 30 minutes) is recommended for the adults but not required. You may even get a taste of the specialty of the house — liquid-nitrogen ice cream — though competition can be fierce.

If you can help with one or more of the LN workshops or in other ways (such as preparing the materials in the morning) or have any questions, please contact Ina (x4341, There are other opportunities to help with Daughters and Sons to Work Day; please contact Joe Crippen of the Lab’s Workforce Education and Development office (

How Your Kids Can Participate

student, Ina Reichel, and Dan Dietderich
ATAP’s Ina Reichel (center) and Dan Dietderich pass cryogenics knowledge to eager and properly protected young hands
The Lab has a variety of programs appropriate for different age groups. All programs include a lot of hands-on science.

Daughters and Sons to Work Day is not restricted to children (or grandchildren) of employees: any employee can bring up to three children. Advance sign-up is required, and there is a modest fee covering the T-shirts, lunch and some of the materials; sign-up instructions will be published in Today at Berkeley Lab.

You can sign up your own child and be a volunteer.

Nuclear Science Day for Scouts, Saturday, April 29

scouting day 2016
Preparing for a hands-on demo
On Saturday, April 29th, the Nuclear Science Division is again hosting the Nuclear Science Day for Scouts. Boys can work toward the Nuclear Science merit badge; girls can earn the “Get to Know Nuclear” badge.

Volunteers are needed to help with materials, logistics, chaperoning of groups, and a variety of other tasks.

The program includes tours of the Advanced Light Source, so tour guides with specific knowledge of the ALS are especially needed.

For general volunteer signup, visit

If you’re affiliated with a Scout troop, signing up as a volunteer increases the likelihood that your troop will be accepted for this space-limited event.

For both Daughters & Sons to Work Day and Nuclear Science Day for Scouts, we welcome volunteers from all job categories. It takes a lot of people in many walks of life to make the Lab run smoothly, and this is a great chance to share your part in it.

So come out for one or both events! It’s fun, you’ll come away reassured about the future after finding out just how hard a question a 9-year-old can ask, and who knows — maybe you’ll get name-checked as a key early influence in a 2040 Nobel lecture!


Does Something Smell Phishy? Learn How to Avoid Taking the Bait

phishhook “Phishing” — e-mail that look like legitimate official or personal correspondence, but in fact misleads you into entering sensitive information or inadvertently installing spyware or other malware on your computer — is one of the leading tools of cybercriminals.

Phishing season is year ’round, but this is an especially risky time because many of these scams are disguised as mail from the Internal Revenue Service. Phishing e-mails can be quite plausible in appearance, and even sophisticated users who let their guard down can get hooked and reeled in.

LBNL’s IT Division has developed a new program to raise and maintain our ability to spot “phishing.” Sign up for it and from time to time you’ll get a harmless e-mail crafted by their cybersecurity staff to resemble the latest phishing scams. Users who have tried out out are reporting the experience to be educational and informative, as well as a fun challenge. Give it a try and learn how to protect your computer and the official systems linked to it.

To Learn More…

The Lab’s required annual Computer Security Refresher Course has information on phishing (and many other threats) and may be re-taken at any time. You can also learn about phishing from the Federal Trade Commission and (with an emphasis on tax season) the IRS.

Hone Your Communication Skills with a Free Workshop March 27

CSimpson_100x100y Continuing their efforts to promote professional development at Berkeley Lab, the Diversity and Inclusion Office has partnered with Cindy Simpson from the Association for Women in Science (AWiS) to host a workshop entitled, “Effective Communication Tips and Techniques.”

The workshop is open to all employees and will be held on Monday, March 27, 2017, 1:00-3:00 p.m. in Building 59, Room 3101. (A morning session is also being offered for postdocs.)

The learning objectives of the Effective Communication Tips and Techniques workshop are to provide participants with:

  • An understanding of the different influencing factors that inhibit effective communication;
  • A review of the techniques that can be employed relating to verbal and nonverbal communication; and
  • A comprehensive approach on how to improve their communications style.

The workshop is free to employees, but registration is required. To register, please complete this form.


safety day poster excerpt ATAP and Engineering Division* Safety Day, Wednesday, March 29
Please mark your calendars for this “all hazards, all hands, all day” event!

*Engineering staff matrixed to ATAP.

With safety as our top priority, ATAP and the Engineering Division will hold a joint Safety Day March 29th, 2017. This will take place throughout our workspaces in Building 46, 46B, 47, 53, the 58 complex, the 71 complex, 77 and 77A.

Safety Day is a chance to step aside from our busy routines and take a fresh look at the tidiness, organization, and safety of our offices, labs, shops, and common areas.

This will be an all-day stand-down for everyone in ATAP, as well as Engineering staff matrixed to us. The only work we will perform that day will be cleanup, QUEST walkthroughs, and other tasks relevant to environment, safety, and health. We expect everyone** to join in unless travel has already been scheduled or illness prevents participation, so please block out March 29 on your calendar and plan on being part of the communal effort.

**Advanced Light Source Accelerator Physics staff will participate in the ALS Division’s Safety Day instead.

An entire day devoted to safety may seem like a lot — but it is less than 0.5% of the work year, and we all have to do our part to keep work areas clean and safe for science.

What’s next?

We’ll be back in touch with further details, and will post resources on our website. In the meanwhile, you can get ready by saving the date (Wednesday, March 29, 2017) and glancing around your workspace with fresh eyes: What can be better organized, sent to Excess or recycling or the trash; or improved?

If you have any questions or would like more information, please contact either:

● ATAP EHS&S Coordinator Pat Thomas (, 510-486-6098 or 510-599-5579.
● Engineering EH&S Coordinator Marshall Granados (, 510-486-7915 or 510-470-0450.