Director’s Corner: ALS-U and Other Opportunities
Fall brought wonderful news in the form of Critical Decision Zero for the Advanced Light Source Upgrade: its official beginning as a project, and the start of an exciting journey to a next-generation user facility for the Office of Science, LBNL, and ATAP. Read on to learn more about the R&D prospects unfolding in our future and how we are organizing to meet these challenges, as well as several honors earned recently by our people.
ALS-U Technical Spotlight: Main Ring Lattice
Wim Leemans Wins IEEE’s PAST Award
Cameron Geddes, Christoph Steier Named APS Fellows
DOE Secretary Honors ALS Brightness Upgrade Team
Shlomo Caspi Wins IEEE Superconductivity Award
Earlier this month, the Department of Energy announced Critical Decision Zero, the “statement of mission need” that begins a major project, for the Advanced Light Source Upgrade. The influential Basic Energy Sciences Advisory Committee has called ALS-U “absolutely essential” to its portfolio of light sources, and LBNL Director Michael Witherell has declared it a very high priority for the Laboratory.
The technical goal is most ambitious: a “diffraction limited” light source, which requires a storage ring at the edge of what is achievable. Because the ALS is a highly subscribed user facility, ALS-U will have to be a tour de force of project management as well as science and technology.
ALS-U will be an exciting challenge in every way, but we look forward to working with the ALS and Engineering Divisions to reprise the success that the ALS enjoyed when originally built. This issue of the newsletter will focus primarily on ALS-U, which of course will be highlighted often as the design phase makes progress toward a hoped-for construction start.
Meanwhile, efforts continue to make the present ALS the best it can be in performance and service. The efforts of ATAP and others toward a major improvement in its photon-beam brightness were recently recognized with the prestigious Secretary of Energy’s Achievement Award. We have also coordinated with the ALS Division to ensure that both the continuing effort to maximize the beam quality and therefore the science of the existing machine and the design process for ALS-U have the leadership they need.
David Robin has become Project Director for ALS-U. Fernando Sannibale, principal investigator of the Advanced Photoinjector Experiment and the closely related LCLS-II injector project, takes David’s place as our program head for ALS Accelerator Physics, along with the new title of ALS Division Deputy for Accelerator Operations and Development. Having two people of that caliber on staff — both of them deeply familiar with the ALS and long accustomed to collaborating — is a prime example of how it is ultimately our people who make leading-edge progress possible.
One of the key aspects of the design process for any new accelerator these days is computer simulation or modeling. In recognition of the burgeoning importance of this field — and the exciting challenges that it faces in the push toward exascale computing — we have created a new Modeling Program. ATAP’s Jean-Luc Vay, an internationally recognized leader in the field, will head this new program, drawing on the expertise of BELLA Center and the Center for Beam Physics.
Progress in accelerators has always gone hand in hand with the achievable strength and quality of magnets, and these are times of both great need and great opportunity for new-generation magnetics. To make progress on multiple fronts simultaneously, we have named Dr. Soren Prestemon as director of the Berkeley Center for Magnet Technology. His predecessor in that role, Dr. Stephen Gourlay, leads the U.S. Magnet Development Program, a recently created high-energy-physics program of national scope.
ALS-U: TRANSFORMATIONAL X-RAY PROJECT TAKES A STEP FORWARD
The ALS Upgrade has recently taken an important step in getting closer to becoming reality: On Sept. 27, ALS-U received “critical decision zero” (CD-0), which approves the scientific need for the project. This initial step sets in motion a process of additional planning and reviews, and the beginning of the upgrade’s conceptual design phase.
ALS-U takes advantage of a more than half-billion-dollar investment in the existing machine, said David Robin, director of the project. The next milestone of DOE project review and approval, known as CD-1, would confirm site selection for the proposed project; this would mark the end of the project definition and conceptual design phase and provide a cost range.
This issue of the newsletter will focus on ALS-U. An overview that sets the project in context is followed by four technical briefs on topics of recent progress: the main-ring lattice; pulsers and injection; a stripline kicker; and harmonic cavities.
“ALS-U will allow us to continue to lead the world in measuring and understanding new materials and chemical systems”
— ALS Director Roger Falcone
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|ALS-U is projected to have the highest coherent flux, in its prime spectral range, of any existing or planned light source. With brighter, more coherent beams than the present ALS, it will approach the fundamental limits in performance for soft X-rays, opening new doors for researchers.
For example, it can be used for studying materials at the nanoscale, mapping their physical, chemical, and electronic structure as those attributes evolve in real time. Modern materials are complex and inherently varied, so their functionality can only be understood by measuring this non-uniformity in their properties.
Researchers could use these beams, for example, to produce 3-D maps of battery and fuel cell chemistry at work, which could provide clues that show the way to improved performance. The brighter, more coherent beams could also be used to explore exotic materials phenomena like superconductivity, in which materials can carry electrical current with nearly zero loss; and to study unusual quantum properties that are poorly understood but hold promise for future advances in computing and data storage.
As ALS Division Director Roger Falcone puts it: “ALS now is the world leader in science that utilizes soft X-rays. ALS-U will allow us to continue to lead the world in measuring and understanding new materials and chemical systems for the 21st century.”
New user science calls for better performance; new accelerator science and technology enables it
The ALS was designed largely in the 1980s and was in the vanguard of “third generation” synchrotron light sources when it began user operations in 1993. Over its life there have been numerous upgrades and improvements, both large and small, to keep it among the top-performing soft X-ray sources in the world. Probably the most important performance parameter is the brightness of the light delivered to users, which in turn depends largely on the emittance of the electron beam and thus the beam size and divergence, so that is where most of the attention for upgrades has been focused.
The emittance has been decreased by multiple upgrades over the years — by a factor of three in the horizontal plane and almost an order of magnitude in the vertical plane to the current values of 2000 picometers·rad horizontally and 30 pm·rad vertically. The reduced emittance, together with an increase in average current that was also implemented as part of these upgrades, has resulted in much more than an order of magnitude increase in brightness. However, the emittance has now reached the limit of what can be achieved with the current “lattice,” the set of magnets that steer and focus the beam. Significant further improvements can only be achieved by radically changing the magnetic lattice.
The ALS currently employs a triple-bend achromat lattice, one in which each of the 12 arc cells consists of three dipole bending magnets and several quadrupole focusing magnets. This was the state of the art until very recently; most light sources employ either double- or triple-bend achromats.
To achieve a significantly smaller emittance while keeping the arc cell size similar requires going to a multi-bend achromat (MBA) scheme. An MBA lattice has successfully been implemented at the MAX-IV light source in Sweden and is part of the upgrade plans for the Advanced Photon Source (APS-U) at Argonne National Lab.
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Above left: Computer-aided design (CAD) image of two of the twelve arcs of the multibend achromat (MBA) lattice of ALS-U, together with undulators and photon beamlines. Above right: CAD image showing the new MBA ring together with the full-energy accumulator ring inside the existing ALS shielding.
A major challenge of the new lattice will be its significantly reduced dynamic aperture. The dynamic aperture will be small enough that the injection scheme now customarily used in electron storage rings is not feasible. The solution to this is the “on-axis swap-out” injection scheme, in which, over one turn, some of the bunches are replaced with new ones. This necessitates an accumulator ring, which, in the case of ALS-U, sits in the same tunnel on the inside of the main storage ring.
The upgrade will allow the ALS to become a “diffraction-limited” storage ring with brightness up to 1000x that of the present machine. ALS-U will deliver light to experiments in nearly continuous waves that are more uniform and highly transversely “coherent” and laserlike.
Technical Spotlight: Main Ring Lattice
The lattice design for the ALS-U main ring has to balance competing goals: achieving high brightness while meeting technological limitations (e.g., magnetic gradients) and operational demands (e.g., acceptable beam lifetime). This comes down to a trade-off between small emittance and sufficient particle-dynamics stability.
Low-emittance lattices require strong focusing fields, which result in large chromatic aberrations. Correcting those requires strong sextupole magnets, which in turn lead to strong nonlinearities and reduced dynamic aperture and momentum acceptance.
With the planned swap-out injection instead of the more conventional stacking injection, one can get around the reduced dynamic aperture somewhat, but it is still important to maximize particle stability for beam-lifetime purposes.
Multi-objective genetic algorithms have been employed to optimize the linear and non-linear lattice for a multi-bend achromat (MBA) lattice design. The new lattice uses cell dimensions similar to those of ALS’s current triple-bend achromat so as to fit within the space available and to minimize the number of photon beamline moves.
ATAP’s Changchun Sun, Hiroshi Nishimura, and Marco Venturini played key roles in lattice design/simulations.
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Above, left: Computer-aided-design (CAD) image of a candidate lattice segment that employs nine bending magnets that each deflect the beam by 3.33 °. Above, right: The Twiss functions for one arc.
Various lattice configurations are being studied. In the one shown, the center seven magnets of a segment would consist of geometric quadrupole magnets with a horizontal offset. The ones at the ends would be combined-function dipoles (dipole magnets with a built-in quadrupole component, as in the current ALS). The Engineering Division’s Charles Swenson and Jin-Young Jung are leading the design effort for the challenging MBA lattice magnets.
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|Local momentum aperture for one cell of ALS-U.|
The dynamic aperture of the proposed lattice is adequate for on-axis injection but puts tight requirements on the emittance of the injected beam. The lifetime is projected to be about 0.7 hours, which is deemed workable.
Technical Spotlight: Pulsed Magnets and Injection
In most electron storage rings it is possible to add additional electrons into already-circulating bunches, which allows the use of injectors that cannot deliver the full bunch charge in a single pulse. Instead, one can simply stack several injector pulses in the main ring. However, this requires a large enough physical aperture, as well as dynamic aperture, in the storage ring, as the newly injected electrons will oscillate transversely (which in most cases means horizontally) around the already-circulating bunches.
In order to achieve the highest brightness, ALS-U will need a small physical and dynamic aperture, so this method cannot be used. Therefore, ALS-U will make use of a different method, on-axis swap-out injection. To enable this, the present storage ring will be replaced by two rings: a main storage ring with the user photon beamlines, and an accumulator ring that is located next to the main storage ring in the same tunnel.
During user operations, when the current in the main storage ring falls below the target value, a train of 25 bunches is injected from the accumulator into the main storage ring by the use of fast kicker magnets. At the same time, the same fast kicker magnets extract a depleted train of 25 bunches. The injected beam goes into that space while the depleted train is transferred back to the accumulator ring. Thus, within a single turn, one of the 11 bunch trains in the main storage ring is swapped with the single bunch train in the accumulator. In between swap-out cycles, the single train in the accumulator gets replenished to make up for beam lifetime losses in both the storage ring and the accumulator by using standard top-off injection.
This technique is currently not used anywhere and required significant R&D to develop the needed stripline kickers and pulsers.
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|Layout of the injection and extraction regions of storage ring and accumulator for bunch train swap-out.
Two prototype pulsers using different technologies — an inductive adder, discussed below, and a transmission-line adder — were developed by Will Waldron and Chris Pappas of the Engineering Division. The inductive-adder pulser has already shown the required very short rise and fall times (<7 ns) as well as the required flat-top length (50 ns) and flatness (<±5%) at full voltage. The transmission-line adder is earlier in its testing cycle. The Lab has also worked with two companies to explore commercial options and is collaborating with the Advanced Photon Source Upgrade team at Argonne.
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|Far left: Full eight stage inductive adder built at LBNL. Near left: Positive and negative pulse at 105% of nominal voltage demonstrating minimum required pulse parameters.|
Technical Spotlight: Stripline Kicker
The fast kicker magnet is based on a matched stripline design and has a small aperture to achieve the necessary kick angles. This can pose some challenges. One is that the beam-coupling impedance can lead to instabilities; another is beam-induced heating of high-voltage feed-throughs, high-power loads, and the kicker structure.
Cold model of the stripline kicker.
A prototype of a suitable kicker that will be tested in the present ALS was developed by Chuck Swenson and Chris Pappas of the Engineering Division, together with Stefano de Santis, Tianhuan Luo, and Christoph Steier of ATAP. The cold model of the kicker was tested successfully earlier this year with time-domain reflectrometry (TDR) and wire impedance measurements. A kicker to be installed for the test in the ALS is currently being manufactured at Berkeley Lab and will be installed in January 2017 for extensive testing with beam.
This kicker has the electrode spacing required for ALS-U but has a larger horizontal aperture in order to be compatible with the requirements in the ALS storage ring, which actually makes its design more challenging than that of the eventual one for ALS-U. The ALS prototype kicker will be compatible with the requirements of the ALS-U accumulator ring without any changes.
Technical Spotlight: Harmonic Cavities
Due to the very small emittances in the ALS-U main ring, scattering effects within the beam play an important role. Intra-beam scattering can lead to emittance growth, a detriment to performance, and Touschek scattering can lead to particle losses, which would reduce the lifetime of the stored beam. Harmonic cavities, which lower the particle density by stretching the bunches, are needed to mitigate these effects.
The third-order harmonic cavities for ALS-U are designed to lengthen the bunches by about a factor of four, which is beyond what is routinely achieved in existing rings. The main challenges are transient effects due to inhomogeneities, especially gaps, in the fill pattern. However, simulations showed that tailoring the fill pattern used for bunch train swap-out should allow to achieve the necessary lengthening factors.
Experiments were performed by Stefano de Santis and Christoph Steier at the current ALS, running in a fill pattern and rf configuration similar to those planned for ALS-U. These beam tests have demonstrated that the necessary lengthening factors are feasible with the fill patterns compatible with the concurrently developed pulsers and stripline kickers.
Other mitigation measures for reducing the effect of scattering processes will also be used in ALS-U, including running the machine fully coupled and maximizing the number of filled RF buckets.
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|Far left: ALS-U type fill pattern with 11 trains of 25 bunches used in the bunch lengthening experiments as well as phase transients induced by this fill pattern. Near left: Streak camera image of the lengthened buches (showing 2 full and 2 partial bunch trains) with a lengthening factor of about four.|
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DAVID ROBIN NAMED ALS-U PROJECT DIRECTOR; FERNANDO SANNIBALE TO HEAD ALS ACCELERATOR PHYSICS PROGRAM
Accelerator physicist Dr. David Robin of ATAP has been named project director of the Advanced Light Source Upgrade (ALS-U). He was chosen for this role by LBNL Director Michael Witherell in collaboration with ATAP Director Dr. Wim Leemans and ALS Director Dr. Roger Falcone.
Fernando Sannibale, presently the principal investigator of the Advanced Photoinjector Experiment at LBNL, will take Robin’s place as leader of the ALS Accelerator Physics program in ATAP and will also serve as the ALS Division Deputy for Accelerator Operations and Development.
Robin, a senior scientist in the ATAP Division and a Fellow of the American Physical Society, has been with LBNL since receiving his doctorate from the University of California, Los Angeles in 1991. After spending two years working on the design of the PEP-II B-Factory, he joined the ALS accelerator physics staff, leading the Accelerator Physics Group starting in 1999, then became ALS Deputy for Accelerator Operations and Development in 2005.
As group leader, Robin led highly successful ALS accelerator upgrades, including the superbend upgrade (completed in 2001) and the top-off upgrade (completed in 2009). He recently accepted the 2015 Secretary of Energy Achievement Award for the 2013 brightness upgrade of the ALS on behalf of the team led by his deputy, Christoph Steier.
“Dave has devoted much of his career to keeping the ALS at the forefront of light-source performance,” said Leemans. “Technologies, user demand, and opportunity are coming together to let us build the ultimate version of the ALS, and Dave and his team are in a great position to lead us there.”
ALS-U will enable the production of highly focused beams of soft x-ray light that are up to 1000 times brighter than those of the existing ALS by employing an improved electron storage ring. The new ring will use a dense array of powerful, compact magnets known as a multibend achromat (MBA) lattice, which has been successfully demonstrated at the new MAX-IV facility in Sweden. In combination with other improvements to the accelerator complex, the new machine will produce highly coherent x-ray beams capable of probing matter with unprecedented detail.
“Now the real work begins,” added Robin, noting that CD-0 is just the start of the project, kicking off the conceptual design and project definition phase that must undergo rigorous reviews before achieving the next major DOE milestone, CD-1.
The ALS got its start in ATAP’s predecessor organization, the Accelerator and Fusion Research Division. ATAP continues to provide accelerator physics and technology leadership for the many upgrades of the machine.
Continuing to improve the ALS in the meanwhile
To take Robin’s place as head of the ALS Accelerator Physics Program, Leemans and Falcone named Fernando Sannibale as the ALS Division Deputy for Accelerator Operations and Development.
Sannibale, a senior scientist in ATAP and a Fellow of the American Physical Society, has more than 25 years of experience in accelerator physics. His expertise includes storage rings for colliders and light sources, high-brightness electron sources, free-electron lasers (FELs), and accelerator instrumentation.
In addition to being a member of the ALS Accelerator Physics Program, for the last seven years Sannibale has been the principal investigator for APEX, the Advanced Photoinjector EXperiment. APEX is an injector test facility developed to test a novel concept called the “VHF-gun,” an electron source conceived at LBNL and optimized for operation in high-repetition-rate x-ray FELs. Based on the successful results at APEX, the VHF-Gun has been selected as the electron source for the Linac Coherent Light Source-II, the high-repetition rate free-electron laser being built at SLAC National Accelerator Laboratory.
“David and Fernando are internationally admired accelerator physicists, they have made enormous contributions over many years at the ALS, and I am very pleased to see them engaged in these critical roles for our facility and our users,” said Falcone. “It’s a pleasure to work with them and the entire ALS accelerator physics team.”
“With the ALS-U CD-0 approval, the years to come will be an exciting but challenging period,” said Sannibale. “The needs of the operational ALS with its 2,500 users and the growing resource demand from the new ALS-U, must be carefully managed and coordinated by the two divisions’ leadership teams to ensure effective progress and success for both activities. I am looking forward to playing my part.”
NEW ATAP PROGRAM FOCUSES ON ACCELERATOR MODELING
In recognition of the importance of computer simulation in today’s accelerators, ATAP Division Director Wim Leemans has established a new program, Accelerator Modeling, that focuses on developing and applying advanced computational techniques to the understanding of machines and beams.
ATAP senior physicist Jean-Luc Vay will head the program, which draws its core personnel from the Berkeley Lab Laser Accelerator Center (BELLA) and the Center for Beam Physics, among our most computationally intensive efforts.
“These are tremendously exciting times to work in accelerator modeling,” Vay said. “There is great demand for high-performance codes and for transitioning them to future supercomputing architectures. A dedicated modeling program will be an opportunity to use LBNL’s strengths to serve these needs of the accelerator community.”
After earning his doctorate in 1996 from the University of Paris, Vay came to LBNL as a postdoctoral researcher and was appointed as a career staff member in 2000. He received the 2013 US Particle Accelerator School Prize for Achievement in Accelerator Physics and Technology for original contributions to the development of novel methods for simulating particle beams, particularly the Lorentz boosted frame techniques, and for the successful application of these methods to multi-scale, multi-species problems. Vay also received the 2014 NERSC Award for Innovative Use of High Performance Computers for his work on boosted frame and novel spectral decomposition techniques.
“Modeling is crucial to how we design accelerators today, and even how we operate them,” says Leemans. “Concentrating our efforts with this new program will help us lead the way to higher performance modeling, which means better accelerators.”
That requires high-performance, high-fidelity modeling of complex processes that develop over a wide range of space and time scales. This in turn calls for next-generation “exascale” computing power, with performance 50 to 100 times greater than that of today’s typical supercomputers, as well as software customized to take full advantage of it.
Vay recently received funding from DOE’s Exascale Computing Project for an effort in modeling of advanced particle accelerators. It will push toward the ambitious ten-year goal of modeling a chain of 100 laser-plasma acceleration stages in less than a week — hopefully less than a day — of computer time.
“Accelerator modeling is an opportunity to help lead the way to exascale applications,” says Leemans, noting that transforming science through exascale computing is one of Director Witherell’s strategic priorities for the Laboratory.
The recent report by the Accelerator R&D Subpanel of HEPAP, the High Energy Physics Advisory Panel, concurs. The Subpanel observed that “advancing the capabilities of accelerator simulation codes to capitalize on the drive toward exascale computing would have large benefits in improving accelerator design and performance.” Coupled to algorithmic advances, it will “enable reaching the ultimate goal of realtime virtual prototyping of entire accelerators” — the detailed and accurate end-to-end modeling that has long been a dream of the accelerator simulation community.
“An opportunity to help lead the way to exascale applications”
— ATAP Director Wim Leemans
ATAP has long been among the leaders in accelerator modeling, often working together with LBNL’s Computing Research Division and National Energy Research Supercomputing Center (NERSC), as well as colleagues at other laboratories and universities in the U.S. and abroad. A recent article by NERSC's Kathy Kincade discusses an example, the code WARP IV, and puts it in the context of the computing and visualization synergies to be found at LBNL.
Those existing efforts are already coming together through the Berkeley Lab Accelerator Simulation Toolkit (BLAST), which spans various ATAP programs, and the nascent multi-institutional Consortium for Advanced Modeling of Particle Accelerators (CAMPA). The new Modeling Program will bring together these activities, already under Vay’s coordination, into a unified framework.
A Project to Take Accelerator Simulations to the Exascale
The Department of Energy’s Exascale Computing Project (ECP) has announced support for 15 critical research applications for next-generation supercomputers, and ATAP will lead one of them: “Exascale Modeling of Advanced Particle Accelerators,” with Vay as principal investigator.
This project supports the practical and economic design of smaller, less-expensive plasma-based accelerators. Turning the plasma accelerator from a promising technology into a mainstream scientific tool depends critically on high-performance, high-fidelity modeling of complex processes that develop over a wide range of space and time scales. Lawrence Livermore National Laboratory and the SLAC National Accelerator Laboratory will also participate in the project.
With 50 to 100 times the performance of today’s typical supercomputers, “exascale computing will be able to accomplish in minutes to hours what presently would take days to weeks,” adds Vay. This will enable accelerator designers to perform far more-detailed and higher-fidelity simulations and to examine more-complex phenomena.
The ten-year challenge taken up by the proposal is the modeling of a chain of up to a hundred plasma acceleration stages in less than a week, and ideally less than a day.
The recent report by the Accelerator R&D Subpanel of HEPAP, the High Energy Physics Advisory Panel, observed that “advancing the capabilities of accelerator simulation codes to capitalize on the drive toward exascale computing would have large benefits in improving accelerator design and performance.” Coupled to algorithmic advances, such as the Lorentz boosted frame approach, adaptive mesh refinement, scalable spectral electromagnetic solvers, and numerical Cherenkov instability mitigation methods, it will “enable reaching the ultimate goal of realtime virtual prototyping of entire accelerators” — the detailed and accurate “end to end” modeling that has long been a dream of accelerator simulation.
“This accelerator modeling project embodies the new paradigm of combining experimental and computational methods to advance a critical technology,” said James Symons, LBNL’s Associate Laboratory Director for Physical Sciences. “Realizing the potential of plasma-driven accelerators will impact fields ranging from health care to manufacturing to basic research.”
|Supercomputer simulations of plasma-based accelerators typically use a “moving window” to restrict the simulation area to a region of interest that encompasses the laser beam and the portion of wakefield that accelerates the electron beam. In this small-scale simulation meant to illustrate the physics, a laser beam (red and blue disks) propagating through an under-dense plasma displaces electrons, creating a wake that supports very high electric fields (pale blue and yellow), that can accelerate an electron beam (white) to high energy in a short distance. While the simulation box is spatially much smaller, the number of time steps that are required to simulate the crossing of the laser through the plasma is still very large, typically over a million. Exascale computers, 50-100x more powerful than today’s typical supercomputers, will be game changers for what we can feasibly model.|
ECP Work Will Be Next Stage of an Ongoing Effort
“We’ve spent years preparing to take advantage of this opportunity,” Leemans observes.
Vay coordinates the Berkeley Lab Accelerator Simulation Toolkit (BLAST) effort and the emergent multi-laboratory Consortium for Advanced Modeling of Particle Accelerators (CAMPA). Vay also leads the NERSC Exascale Science Applications Program (NESAP) project on Advanced Modeling of Particle Accelerators. NESAP was launched in 2014 to prepare for NERSC’s newest supercomputer.
Exascale To Be a Big Part of Lab’s Future, and Vice Versa
Of the 15 fully funded ECP proposals, Berkeley Lab will lead two and participate in four others. An additional seven proposals received seed funding; Berkeley Lab will lead three and participate in two others.
“These awards reflect our extensive experience and expertise in computational science across a wide range of disciplines, including accelerator design, subsurface flows, cosmology, combustion, chemistry,” said Kathy Yelick, Associate Laboratory Director for Computing Sciences. “Our applied mathematics and computer science expertise will be needed to develop applications tailored to exascale systems.”
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Kathy Kincade of NERSC has written a feature article, “The Incredible Shrinking Particle Accelerator,” that sets some of the modeling work in the larger context of high-performance computing at LBNL and the synergies and support to be found here.
PRESTEMON NAMED BCMT DIRECTOR; GOURLAY TO LEAD NEW U.S. MAGNET DEVELOPMENT PROGRAM
ATAP Division Director Wim Leemans has named Dr. Soren Prestemon as director of the Berkeley Center for Magnet Technology. Prestemon replaces Dr. Stephen Gourlay, who is now serving as Director of the U.S. Magnet Development Program, a recently created DOE high-energy-physics program.
“Launching the new national magnet development program and taking BCMT into its second year opens up great opportunities for two of our top people,” says Leemans.
Prestemon came to LBNL as a research engineer in 2001 after earning his doctorate from Florida State University — host of the National High Magnetic Field Laboratory, which is one of the partners in the new U.S. Magnet Development Program. Previously he had studied mathematics at Université Joseph Fourier and engineering at the Institut Polytechnique de Grenoble.
“Soren brings a unique perspective to BCMT,” he adds. “He’s a member of LBNL’s Engineering Division, has worked closely with the Advanced Light Source on magnet development, and for two years was head of our own Superconducting Magnet Program. Since the creation of ATAP he has been my Division Deputy for Technology. The whole idea of BCMT is to bring together magnetics expertise from ATAP and Engineering, so he’s a great fit.”
“In providing innovative and groundbreaking technology, combined with a disciplined engineering approach, Soren has been a key resource in developing magnets and undulators for LBNL’s facilities and the broader national and international programs LBNL is engaged in, ” adds Henrik von der Lippe, Director of the Engineering Division.
Prestemon takes over BCMT at an exciting time in accelerator-related magnetics. Besides colliders for high-energy physics, new-generation synchrotron-light sources — both free-electron lasers such as Linac Coherent Light Source-II, being built at SLAC, and diffraction-limited light sources based on storage rings, like LBNL’s proposed ALS Upgrade — are being envisioned and pursued. Such facilities will require pushing forward the state of the art in the design, construction, and measurement of magnets of all kinds. Other applications currently under development include electron cyclotron resonance ion sources, medical-treatment gantries and fusion-energy facilities. Many of these projects involve multi-institutional and even international partnership.
“The BCMT will help foster communication channels and coordination,” says Prestemon. “This approach is truly the best way to integrate design and construction into applications with our partners.”
Advanced magnets: essential parts of the future of HEP
One of the most magnet-dependent sciences is collider-based high-energy physics, which probes the fundamental nature of matter and energy with machines like CERN’s Large Hadron Collider. Nature does not give up such deep secrets easily or cheaply, and magnets play an important role in the technology and cost of colliders.
Gourlay heads the U.S. Magnet Development Program, an LBNL-led multilaboratory initiative recently launched by the DOE’s Office of High Energy Physics. The MDP has an ambitious technical mission to push multiple aspects of the performance of superconducting magnets while reducing their cost. Its success is considered key to future high-energy physics proton colliders.
In ATAP’s Superconducting Magnet Program, Gourlay was instrumental in three successive field-strength records for accelerator-style magnets. “Our program has an unbroken series of field-strength records, and what’s more, they’ve done that with a series of different technologies, always innovating,” observes Leemans.
LARP, the Large Hadron Collider Accelerator Research Program, also flourished here under Gourlay’s leadership. One of LARP’s results, achieved in partnership with Brookhaven National Laboratory and Fermilab, is a focusing quadrupole design for a beam-luminosity-increasing upgrade of the LHC. These magnets will make the LHC the first collider to use niobium-tin superconductor in a major role. Magnet designs that realize the promise of this high-performing but hard-to-work-with material have been a hallmark of Gourlay’s LBNL career and will be a prominent theme of the Magnet Development Program.
The other charter members of the partnership — Fermilab and Florida State University’s National High Magnetic Field Laboratory — have strong capabilities and distinguished achievements of their own, making for a powerful and well-rounded combination. “With the combined resources and infrastructure of the MDP partners, we have an extraordinary opportunity to take the U.S. leadership in high field superconducting magnets to an unprecedented level,” Gourlay says.
Gourlay started his career at Fermilab in 1985 after earning his Ph.D. from the University of California, Davis. Working at first on the user-science side of high-energy physics, he turned his attention to magnets in 1988, contributing to the Tevatron Collider and the Superconducting Super Collider. After a one-year appointment at CERN, he came to LBNL in 1997, serving twice as Superconducting Magnet Program head and for eight years as director of ATAP’s predecessor, the Accelerator and Fusion Research Division.
ION BEAM ANALYSIS FACILITY AVAILABLE TO USERS
After years of operating it jointly with LBNL’s Materials Science Division, ATAP now operates the ion beam analysis facility. The facility, located in Building 53, Room 008, is accessible for a modest fee to both intramural and outside users. Based on a Pelletron accelerator, it provides a complete suite of capabilities, including Rutherford backscattering, for rapid analysis of thin films with an energetic ion beam.
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HONORS AND AWARDS
Leemans Wins IEEE’s PAST Award
Brookhaven’s Ilan Ben-Zvi (l.) presents the award to Leemans
| ATAP Director Wim Leemans was recognized with the IEEE Particle Accelerator Science and Technology Award. He received the award in an October 13 ceremony at the North American Particle Accelerator Conference (NA-PAC 2016).
Leemans was honored “for pioneering development of laser-plasma accelerators.” One of the leaders in the field, he is director of ATAP’s Berkeley Lab Laser Accelerator (BELLA) Center as well as of ATAP. He had already been elected a Fellow of the IEEE.
At each NA-PAC, the IEEE Nuclear and Plasma Sciences Society gives this award to two individuals who have made outstanding contributions to the development of particle accelerator science and technology.
“It’s quite an honor to be in such company,” says Leemans of the accelerator science and technology luminaries who have been recognized with the PAST Award. He joins four previous recipients from ATAP and its predecessor organizations, starting with inaugural winner L. Jackson Laslett and including Ronald M. Scanlan, Ka-Ngo Leung, and Alpert Garren.
Geddes, Steier Named as Fellows of the American Physical Society
APS Fellows are recognized by their peers “for exceptional contributions to the physics enterprise; e.g., outstanding physics research, important applications of physics, leadership in or service to physics, or significant contributions to physics education.” Geddes and Steier join 25 other present and former staff members of ATAP and its predecessor organization, the Accelerator and Fusion Research Division, to be so honored. Five other researchers associated with Berkeley Lab also received the distinction this year.
Energy Secretary Recognizes Achievements of ALS Brightness Upgrade Team
The team behind the Advanced Light Source Brightness Upgrade was honored recently with the prestigious Secretary of Energy Achievement Award.
|Left (l-r): Franklin “Lynn” Orr, Under Secretary for Science and Energy; Deputy Secretary Elizabeth Sherwood-Randall; ATAP’s David Robin, program head for ALS Accelerator Physics; and Ernest Moniz, Secretary of Energy at the September 15, 2016 ceremony. Right: ATAP accelerator physicist Christoph Steier with one of the new sextupole magnets that were key to the brightness improvement.|
The four-year, $5.8M project, concluded in 2013, was the largest of the many improvements to the ALS storage ring in its more than 20-year history. Despite its scope and the fact that it amounted to major surgery on the storage ring, the brightness upgrade was completed under budget and months ahead of schedule, with no “teething period.” The improvement solidified the national user facility’s position as one of the world’s brightest sources of soft x-rays.
To Learn More…
The ALS website has further information on the work that led to the award, as well as a roster of the entire team from the ALS, ATAP, and Engineering Divisions that made it possible.
IEEE Honors ATAP & Engineering’s Caspi
Shlomo Caspi, of LBNL’s Engineering Division and ATAP’s Superconducting Magnet Program, has been honored with the IEEE Award for Continuing and Significant Contributions in the Field of Large Scale Applications of Superconductivity. He received the award in a September 5, 2016 ceremony at the IEEE Applied Superconductivity Conference.
Dr. Caspi was recognized for continuing and significant contributions in the field of large scale applications of superconductivity, in particular:
“Our program has a series of field-strength records for accelerator-style magnets, and Shlomo has been involved all of them,” says Stephen Gourlay, Director of the LBNL-led U.S. Magnet Development Program. Gourlay adds, “For more than 20 years he’s been driving design innovation in learning how to make practical magnets out of niobium-tin” — the brittle high-field superconductor that will be key to next-generation high-energy physics colliders and many other applications.
Caspi has led progress in tools as well as products; the Superconducting Magnet Program has achieved what Gourlay calls an “unprecedented and still unequaled” level of integration of software for both the magnetic and the mechanical aspects of design.
Caspi remains involved in some of the latest challenges in superconducting magnet design, including canted cosine-theta (CCT) layouts, which hold the promise of simpler magnets based on brittle superconductor as well as intrinsic relief of the internal stresses that can cause magnets to “quench” or lose their superconductivity.
“Shlomo’s design innovation has played a huge role in our success, and he’s still doing cutting-edge work with the CCT magnets,” says ATAP Director Wim Leemans, adding, “His contributions are a strong basis for the U.S. Magnet Development Program that we now lead.”
“The creativity that Caspi has provided in identifying new areas where superconducting magnets can serve the science and societal needs has been a signature of his career in this field. We owe Caspi a great thanks for this contribution and the IEEE award clearly recognizes this,” adds Henrik von der Lippe, director of the Engineering Division.
The award is conferred by the Council on Superconductivity of the Institute of Electrical and Electronics Engineers, and recognizes “a living individual for a career of meritorious achievements and outstanding technical contributions in the field of applied superconductivity.” Among the 54 previous honorees are four from LBNL, three of whom are from or affiliated with ATAP and its predecessor organizations: Michael A. Green (LBNL and Michigan State University), Al McInturff (LBNL and Texas A&M University), and Ron Scanlan.
Latest in a family of high achieving magnets: Caspi (left) and Gourlay circa 2004, with the dipole HD1 in its cryostat. HD1 set the latest in a series of LBNL field-strength records for accelerator-style magnets at 16 tesla.
These record-setting magnets came from a base program of technically risky but high-potential-payoff R&D that expands the limits of superconducting magnet technology, a high-leverage investment that can benefit a wide variety of applications.
HELP INSPIRE FUTURE SCIENTISTS BY BECOMING AN EDUCATIONAL OUTREACH VOLUNTEER
Educational outreach is a key part of Berkeley Lab’s service to the community. It can take many forms, ranging from helping with a class visit to mentoring a classroom teacher or an undergraduate intern as they assist with research.
LBNL’s Workforce Development and Educational Outreach (WD&EO) Office has a wide variety of opportunities to train and inspire the next generation and to support their teachers. What they all have in common: people like you who volunteer their time and expertise.
Opportunities to Get Involved Now
Volunteer for BLAZES
The Berkeley Lab Adventure Zone in Elementary Education (BLAZES) program, one of the most popular of our educational outreach venues, is holding its next training workshop (registration required) on November 1.
Become a Mentor
If you would like to mentor a student, WD&EO is currently placing interns through the Science Undergraduate Laboratory Internship (SULI) and Community College Internship (CCI) spring programs. Placement will continue through December 9. If you accept a placement early, the position will be fully funded through WD&EO, whereas late placements will have to be funded through the mentor’s own support channels (estimated $15,000 before applicable burdens), so don’t delay! To learn more about how to be a mentor in these programs, click here.
Help Staff Our Booth at APS-DPP
If you are attending the American Physical Society Division of Plasma Physics meeting in San Jose in November, you can volunteer at ATAP’s booth for middle- and high-school students. Please contact Cameron Geddes or Ina Reichel to learn more.
If you would like to know more about outreach programs or mentoring, talk to ATAP’s Coordinator for Outreach and Diversity, Ina Reichel (x4341).
With Thanks to Last Year’s Volunteers and Mentors
To thank the volunteers and mentors for their work in the past year, the Lab’s Workforce Development and Education Office held a reception on September 19th.
| These are some of the many outreach and education volunteers who came from all corners of the Laboratory during the past year. ATAP volunteers included John Byrd, Joe Chew, Anthony Gonsalves, Giselle Jiles, Gregory Penn, Soren Prestemon, Alessandro Ratti, Ina Reichel (our Outreach and Education Coordinator, pictured, front row, second from right), Peter Seidl, and Pat Thomas.
Join us in the coming year and help schoolchildren learn what’s so interesting, important, and just plain fun about what we do!
SAFETY: THE BOTTOM LINE
If you were born in or moved to the Bay Area in 1990 or later, chances are you haven’t experienced a major earthquake. However, if you stay here, it is likely that you will!
According to recent articles in the East Bay Times newspaper, the U.S. Geological Survey (USGS) Working Group on California Earthquake Probabilities predicts a 72% probability of at least one earthquake of magnitude 6.7 or greater striking somewhere in the Bay Area before 2043. There are at least two major earthquake fault systems that could have us rocking and rolling at Berkeley Lab.
The Hayward Fault is literally a stone’s throw from us, passing between the Lab and the campus along its course through the western part of Alameda County and into San Pablo Bay east of San Rafael and Novato. Recent research by the USGS suggests that it is linked to the Rodgers Creek Fault, once thought to be separate, forming one 99-mile fault complex that could deliver up to a magnitude 7.2 quake.
California’s longest and most famous fault, the San Andreas, is also its fastest moving. The USGS reports there is a 22% chance of a 6.7-magnitude earthquake along the San Andreas before 2043. This fault stretches for 800 miles from Southern California through San Jose and west Marin County, then out to sea. Southern California was recently on alert following a swarm of temblors near the Salton Sea. Here in northern California, the fault produced the 1906 earthquake that devastated San Francisco and is capable of giving our side of the Bay a wild ride.
To get ready for the next “big one,” we will be participating in the Great Shake–Out earthquake drill at 10:20 AM on October 20. A public address system announcement will ask you to stop what you are doing, drop to the floor, take cover under sturdy furniture or cover your head, hold on until the imaginary shaking stops, then grab your essential possessions (such as keys, cell phone, jacket, laptop) and evacuate to the nearest emergency assembly area. Building Emergency Team members will be providing direction and assistance.
Here are some more resources to help us prepare before, survive during, and recover after a quake or other disaster.