Berkeley Lab

ATAP News, December 2020

Director’s Corner

As we come to the end of a year like no other, I would like to thank everyone in and around ATAP for your perseverance and dedication. We have continued to make scientific progress while learning a new way of working — and we have stayed safe and healthy doing it.

Researchers from ATAP’s BELLA Center and our Accelerator Modeling Program were key to an international collaboration that demonstrated bi-modal imaging using proton and x-ray beams from the same laser-plasma microsource. Their results recently appeared in Nature Communications. Another happy piece of news came from the DOE Review of CD-3 for the High-Luminosity LHC Accelerator Upgrade Project, following the Fermilab Director’s Review held in late July. We were pleased to see this technically challenging and managerially complex multi-institutional project recommended for CD-3.

Elsewhere in cyberspace, staff from ATAP’s BELLA Center and our Operations team are conducting the AAC Seminar Series in lieu of the pandemic-cancelled Advanced Accelerator Concepts Workshop 2020.

We bid farewell and happy retirement to Senior Division Administrator Martha Condon after 41 years at Berkeley Lab, most of them with ATAP and its predecessor AFRD. Both her innumerable contributions to our operations and her cool, calm, and collected way of making them will be greatly missed.

I leave you with an uplifting symbol of hope. This holiday wreath is actually a scanning electron micrograph image of a drop of SARS-CoV-2 spike protein, in matrix crystals on a carbon nanotube substrate for laser mass spectroscopy. It comes from COVID-response research by a multi-divisional team, including ATAP researchers, here at Berkeley Lab.

Red "wreath" from COVID research

We wish you a happy, healthy, and safe holiday season and a new year of invention and discovery… and don’t forget to check out our social media presence!


An international team, including ATAP scientists Tobias Ostermayr of the Berkeley Lab Laser Accelerator Center and Axel Huebl of the Accelerator Modeling Program, has made the first proof-of-principle demonstration of bi-modal radiographic imaging for biological and technological objects with a laser-driven microsource of x rays and protons. The results were announced December 2 in the journal Nature Communications.

Tobias Ostermayr


Axel Huebl


Ostermayr is lead author of the paper and (together with co-corresponding author Joerg Schreiber of Ludwig-Maximilians-Universität München and Max-Planck-Institut für Quantenoptik) originated the idea. Huebl performed particle-in-cell simulations in support of the study. The experiments were performed with the Texas Petawatt Laser at the University of Texas at Austin.

Synchronized single-sourcing of multiple modalities
Conventional radiography machines produce only a single kind of radiation, such as protons, electrons, or x-rays. Using more than one kind of radiation source gives complementary sets of information about the specimen, but in order to take advantage of this, significant post-processing is usually needed because the sources and image acquisitions were separate in space and/or time.

Laser-driven plasmas can simultaneously emit multiple forms of radiation, including x-rays and protons, and they produce it in short bursts, which is also desirable for, say, “freezing” motion. This study demonstrated, for the first time ever, how such a laser-driven source can be used to make images of biological and technological samples.

Bimodal imaging concept

In this conceptual illustration, a test object (a cricket) casts shadows in a proton beam (green) and an x-ray beam (blue) to record radiographic images with both beams in a single laser shot. The proton image is color coded in blue and red, immediately downstream of the test object; the x-ray image is the grayscale plane at far right. The images show actual experimental data. The laser plasma provides a single source of protons and x-rays, intrinsically synchronized on the nanosecond scale and originating (within µm) from the same spot, as compared to existing, separate sources of these two imaging modalities. Illustration by Tobias Ostermayr, Berkeley Lab.

The team achieved intrinsic nanosecond-scale synchronization of these two powerful and important imaging techniques (compared to seconds or minutes in conventional machines), and the two radiation sources overlapped on a scale of a few micrometers. These attributes, combined with the exquisitely small source size enabled by laser plasma techniques, gave sharper and more detailed insights into materials and samples than could be expected from either source alone—a unique capability of laser plasmas.

In the near future, the researchers hope to extend multimodal imaging capabilities and applications to include electrons and neutrons, and to image dynamic events.

To learn more…
T.M. Ostermayr et al., “Laser-driven x-ray and proton micro-source and application to simultaneous single-shot bi-modal radiographic imaging,” Nature Communications 11, 6174 (02 December 2020).
“A new laser-driven X-ray and proton micro-source,” Attoworld, 3 December 2020.


A DOE Review of the High-Luminosity LHC Accelerator Upgrade Project (AUP) was held (virtually) November 22-24, 2020. The conclusion, as we await the reviewers’ formal report, is that the AUP is recommended for CD-3, the Approval of Start of Construction milestone in the progression of Critical Decisions in a DOE project.

The Large Hadron Collider at CERN will begin a two-and-a-half-year upgrade around 2023, during their third long scheduled shutdown (LS3), to boost the beam’s luminosity and thus the rate of particle collisions. The expertise at the Berkeley Center for Magnet Technology is key to the US contributions to the AUP, an essential component of which is the design and construction of advanced and powerful focusing magnets.

More …

Team picture in front of assembled HL-LHC AUP quadrupole magnet

Fully assembled HL-LHC AUP quadrupole magnet

Berkeley Lab’s contributions, through its Superconducting Magnet Program/Berkeley Center for Magnet Technology (SMP/BCMT), include 104 superconducting wire cables to be used in the magnets; the insulation of the cables; and the assembly of 25 four-meter-long quadrupole magnets designated (MQXFA) that will focus the LHC’s particle beams.

The AUP in total is delivering two of the complete inner-triplet cryoassemblies, designated Q1 and Q3, and 23 magnets in all, while CERN is completing the third cryoassembly, Q2a and b.

“The team is to be highly commended”

The Magnets subcommittee commented that “The project team is to be highly commended for the progress made to date. Significant developments were made since the January 2020 OPA Review,” and added, “The management and technical team across FNAL, BNL and LBNL should be commended on such progress.”

Managerial as well as technical excellence is essential to a program like the HL-LHC AUP, which involves five US national labs and a university, each bringing its particular strengths to the technical challenges — and whose products must mesh with the overall High-Luminosity Upgrade at CERN. The reviewers noted that “The interaction between the project and CERN concerning CERN-produced parts appears to be functioning well” and that “The level of QA actions is commendable.”

The reports will next go to the Energy Sciences Acquisition Adviory Board (ESAAB).


A photo story from the joint ATAP and Engineering Division Berkeley Center for Magnet Technology and ATAP’s Superconducting Magnet Program shows how we can combine safety and productivity in Berkeley Lab’s staged return to onsite work. Click here for higher-resolution versions and additional photos.

Zoom tailgate meeting
Virtual "basic training" for onboarding new employees and "tailgate meetings" to start the day are tremendously helpful tools for the next normal
Office visit

A safe office visit features social distancing, face coverings
Worker with long superconducting magnet

Long superconducting magnets make social distancing easy
Building 58 discussion of day's work

Planning the day's work with COVID prevention foremost
Socially distanced break

Getting out for a bit of fresh air on a fine autumn day
CW from top left: Eric Esarey, Asmita Patel, Soren Prestemon, Thomas Schenkel

Leadership briefing on the day's events


Extensive ATAP Participation in Virtual APS-DPB Meeting

APS-DPB logo

Click for program

The American Physical Society’s Division of Physics of Beams held its 62nd annual meeting online November 9-13. ATAP was well represented; 27 oral presentations and 7 virtual posters out of the 36-strong Berkeley Lab presence had lead or co-authors from BELLA Center, the Accelerator Modeling Program, and the Fusion Science & Ion Beam Technology Program.

Accelerator Modeling Program postdoctoral researcher Ligia Diana Amorim chaired the oral session on Plasma Wakefield Acceleration, and BELLA Center Deputy Director for Experiments Cameron Geddes chaired the invited oral session on X-Rays and High-Energy-Density Physics. Berkeley Lab’s virus-related work was presented in Session TM13: Mini-Conference on Plasma Applications to Ameliorate Covid-19.

Advanced Accelerator Concepts Workshop Goes Virtual With Seminar Series

AAC Seminar Series logo and Web header

Fostering online exchange in advanced accelerators

When the 2020 Advanced Accelerator Concepts Workshop, being organized by the Berkeley Lab Laser Accelerator Center, had to be cancelled due to the pandemic, its organizers put much thought into what they might do instead. Thus was born the online-only Advanced Accelerator Concepts Seminar Series.

The AAC Seminar Series is now on holiday break. Resuming in the New Year, a session dedicated to one of the eight topical working groups will be held every Wednesday morning through February 3, As many as 200 colleagues have been tuning in to these free, by-invitation events.

Xiaorong Wang, Tengming Shen Elected to ASC Board

Xiaorong Wang

Xiaorong Wang

Tengming Shen

Tengming Shen

ATAP’s Xiaorong Wang and Tengming Chen have been elected to the Board of Directors of the Applied Superconductivity Conference. The news arrived at the conclusion of the (virtual) 2020 ASC.

They will serve 6-year terms in this executive steering function.

Both are staff scientists in ATAP’s Superconducting Magnet Program who participate in the cross-divisional Berkeley Center for Magnet Technology and the multi-institutional US Magnet Development Program.

“This is an outstanding testament to their standing in the community, and reflects well on LBNL and our role in the broader community,” said SMP head and BCMT and USMDP Director Soren Prestemon.

The slate of candidates represented the broad areas of interest for the conference. Wang was chosen from the Large Scale Applications area, Shen from the Materials area.

More …

A history of synergy

Held every two years, ASC is among the largest and most important meetings in the field of superconductivity, with some 1600 participants. ATAP has a long relationship with the ASC series. Past ASC Chair Steve Gourlay, the now-retired founding director of the USMDP and SMP/BCMT, organized the short courses. ATAP’s Paolo Ferracin, as well as Wang and Shen, were among the short-course instructors, and Ferracin participated in the interactive student career event ELEVATE. Shen was also honored at the event.

Charlie Sanabria, Tiina Salmi, and Emmanuele Ravaioli, all alumni of our strong program of graduate students, postdoctoral researchers, and visiting scholars, were special-session conveners, and Ravaioli gave a Young Scientist Visions plenary lecture.

SMP/BCMT contributed 18 presentations covering a broad range of magnet R&D topics:
•  The High-Luminosity LHC Accelerator Upgrade Project
•  Diagnostics and high-temperature-superconductor magnets for USMDP
•  Magnets for ion therapy
•  Interaction region quadrupole magnet for the future Electron-Ion Collider
•  A test facility dipole magnet for fusion energy sciences as well as high-energy physics
•  Cryostat development for the SSRF.

Three invited presentations were given by Reed Teyber and Maxim Marchevsky at a special session on magnet quench detection and diagnostics, as well as one by Shen at a session on HTS accelerator magnets.

SMP/BCMT staff also served on the program committee for ASC 2020:
•  Large Scale Applications: Michael Green, Soren Prestemon
•  Materials: Ian Pong, Tengming Shen

Sholmo Caspi, Paolo Ferracin, Maxim Marchevsky, Ian Pong, GianLuca Sabbi, and Shen served as session moderators.

Retired AFRD Director Bill Barletta Honored by APS-DPB

William A. Barletta

Bill Barletta

William A. Barletta, longtime director of ATAP’s predecessor, the Accelerator and Fusion Research Division, has been honored with the Exceptional Service Award of the American Physical Society’s Division of Physics of Beams. The award “recognizes a member of the APS DPB who has made outstanding contributions to the field of accelerators and to promoting the objectives of the DPB.”

Bill currently chairs three APS committees: the Forum on International Physics, the Panel on Public Affairs, and the Division of Physics of Beams. He is author or co-author of four books about accelerator science and technology and another four concerning cybersecurity, privacy and international cyber-law, as well as, most recently, Strategic Management of Research Organizations, based on US Particle Accelerator School classes he has taught.

After years in research and management positions with Lawrence Livermore National Laboratory, during which he often collaborated with Berkeley Lab director emeritus Andy Sessler, Bill moved to Berkeley Lab in 1993 as AFRD Director, a position in which he served until his 2006 retirement. He also headed the Lab’s Homeland Security Office.

Bill has had a diverse and active encore career. He headed the Fermilab-based USPAS from 2006 to 2017; serves as coordinating editor of the refereed journal Nuclear Instruments and Methods in Physical Research, Section A; and in addition to holding adjunct professorships of physics at the Massachusetts Institute of Technology and the University of California, Los Angeles, is a visiting professor of economics at the University of Ljubljana, Slovenia. His recent work at MIT has concentrated on the design and use of high current cyclotrons for both discovery science and industrial applications.


Welcome to 3Q4, in which we put three questions to someone from our staff to help get to know the people behind the science. In this issue, we meet Axel Huebl of the Accelerator Modeling Program, our first-ever Research Software Engineer, and Martha Condon of the Operations Team, who is retiring after 41 much-praised years at Berkeley Lab, almost all of them in ATAP and its predecessor organizations.

Axel Huebl

Axel Huebl


Axel Huebl is a Research Software Engineer with ATAP’s Accelerator Modeling Program (AMP). He had previously been a postdoctoral scholar with AMP after earning his PhD and then working as a scientific researcher at Helmholtz-Zentrum Dresden-Rossendorf (HZDR).

With a background in both the user and the computer-science aspects of modeling, Axel researches, oversees, and participates in the development and integration of codes (computer programs) that run on high performance computers to simulate accelerators, particle and laser beams, and plasmas.

1. Advanced software expertise is in great demand. What led you to accelerator modeling and to the Lab?

More …

During my undergraduate studies, I started out early as an intern at the National Laboratory in Dresden, Helmholtz-Zentrum Dresden-Rossendorf (HZDR). A newly established group on laser-particle acceleration caught my interest and I started writing parallel applications, performed simulations on laser-wakefield acceleration and later on we wrote our own particle-in-cell code that ran on graphics processing units, PIConGPU, which I maintained and improved with my colleagues over many years. In 2012/13, the first large-scale GPU-powered supercomputer came online with DOE’s Titan cluster at Oak Ridge National Laboratory and we were the first from our community that could use its new technology. Since then, I have been a regular user of these facilities – performing science runs on laser-ion acceleration, tackling new challenges to run simulations at very large scale, and collaborating with the vibrant U.S. computational and computer science community.

My way to Berkeley Lab started in 2014 when I met Jean-Luc Vay at the International Particle Accelerator Conference (IPAC) in Dresden. He soon after invited me to visit his group as an affiliate over the course of my PhD studies. Together with Rémi Lehe, whom I had met a few years earlier during an Erasmus internship in Lisbon, we collaborated to kick-start an open standard to exchange particle-mesh data (openPMD) and from there on stayed in regular contact with each other. At the end of my PhD studies, the Exascale Project funded WarpX and I was excited to join, contribute with my experience, and deepen my knowledge on accelerator modeling.

2. You have a talent for communication as well as computer modeling. How do you use that in your role here?

During my time working in the German national laboratory environment, I learned that the truly great physics challenges are only achievable as a team. Efficient communication over open channels, be it in outreach, open data or open source publishing, is a way for me to collaborate and integrate scientific work with many knowledgeable people. This helped me a lot in the past to learn, collaborate, help others, and later on guide new students.

I see computer modeling of particle accelerator science questions as a community challenge that needs to be addressed with interdisciplinary teams. While contributing to individual daily challenges, we use our peers’ work and publish our own research as openly as possible, so that others can reuse or contribute to it. I pre-think and establish mechanisms that make this possible — and surprisingly many technical challenges are rooted in finding ways of efficient and scalable communication, e.g., exchange of data, software, results and reproducibility of computational studies.

3. What is the big-picture goal of what you would like to achieve in your career?

My current career path moves along the boundary of computational physics and computer science. I work in a field with still exponentially growing capabilities, where a computing system that comes online today is pretty much obsolete ten years later. I thrive when I am able to actively shape how we model advanced accelerators with cutting edge technology and develop new workflows on how we can derive insight into complex plasma problems. My background in both physics and computer science inspires me in both domains.

My career goal is to advance our capabilities and understanding in both aforementioned fields to address exciting challenges in laser-plasma physics. Using the most powerful available supercomputers is always an appealing prospect, and building communities that are open and inclusive for members to join, enable each other, build and rely upon each other, and compete openly, is an enjoyable and rewarding way to work.

Martha Condon

Martha Condon portrait and award citation

Excellence, recognized

The end of 2020 is also end of an era in ATAP as one of the hidden figures who support our scientific achievements, Senior Division Administrator Martha Condon, retires from a 41-year career spent principally in ATAP and its predecessor, the Accelerator and Fusion Research Division.

Martha has earned a reputation as the go-to person for the most difficult challenges.Her years of service and dedication were recognized in 2019 with the Laboratory Director’s Award for Exceptional Service Achievement. As her remarkable career comes to an end, the self-effacing superstar of support reluctantly agreed to three questions…

As a manager and central figure of ATAP’s administrative team, you are the pivot point in a lot of other people’s activities. How are you helping them adapt to the new normal of COVID times?

More …

We’ve had to develop a coping mindset. When we all talk, we make time to hear what others are dealing with and what their experiences are so we don’t feel like we’re the only ones going through it.

On Zoom, you just have to expect that interruptions are part of the new normal. I’m in a room where I can just close everything off, but that isn’t everybody’s situation. Getting to know people’s kids and dogs is just part of our new normal, and you work with it.

Technical aspects matter too. Internet speeds vary, and with people in so many places, there’s a greater chance that somebody in a meeting might have some technical problem. There are certain things you have to get around. We just have to be kind to each other and practice acceptance—and build in extra time and be flexible in working around problems. Fortunately, on the admin team we’ve always been there for each other.

You’ve had over 40 years of service to the Lab. What are your thoughts on the changes you’ve seen?

One of the biggest changes has been technology. To me it’s making our jobs easier. Things are getting smaller, but better and faster. When I started out, we were using typewriters, leaving space for equations. It took forever! Then the Wang, which was an early dedicated word processing terminal, came along, and was that a lifesaver. When full-fledged personal computers came along, it was just a no-brainer that things were getting better and better.

Back in the day, scientists would just move up to leadership and management. There has been a big shift to training at all levels, including on how to manage people, and I think that made a big difference.

A work culture of mutual trust and respect and telling the truth is something I’ve seen built up through the years. In the admin field, there’s been a push to help people learn what their strengths are and develop their skills. There’s always been an opportunity to move up, and people guiding me to try something new— seeing your abilities and pushing you to go for it. I’ve really appreciated that throughout my career.

I think the next frontier is for women scientists. The push for equity and inclusiveness continues, and I hope it gives room for women scientists to see their dreams come true.

What advice would you give to other people in roles like yours?

Somebody once called me “cool, calm and collected.” It doesn’t always feel like that inside, but I’m glad that’s the impression I give.

I’ve always been able to say, “I’m going to step away from this and come back when emotions aren’t so high”. I can’t tell you how many times when we come back we have a different perspective on both my end and the other person’s. It’s productive at that point.

Be open to new ideas. Leave room for creativity and see what people can come up with. Recognize them and reward their good work; that’s where you get loyalty and retention, when people are valued. In management, be a role model. Do what you say you’re going to do.

On the few occasions when we see behavior that could be improved, other people should be an upstander—step in to say something. If enough people do the right thing, they can change others. If it’s not just one person saying it, but several, that’s especially powerful.

It’s been a good run, and I’ve enjoyed it. People at the Lab are so brilliant, and being there to support them has been a pleasure.


Coping in a Shelter-In-Place Holiday

Balanced rocks

Resources for keeping your balance

Whether it’s having to find new ways of working, trying to get life’s necessities while minimizing trips and practicing social distancing, or staying home at a time of year that is normally about friends and family, we’re all under a lot of stress these days. Berkeley Lab has a variety of resources to help us find emotional wellness in these times.

Food Banks Need Our Help

Alameda County Food Bank logo

Every dollar counts

Even before COVID, not everyone in our communities had enough, and the economic impact of the pandemic has caused formerly secure people to fall upon hard times. Please consider including the Alameda County Community Food Bank in any charitable giving you do holiday season. Click here to donate in a way that will be counted as part of Berkeley Lab’s Physical Sciences Area in an Labwide competition.

BigFix logo

Automated patches, inventory

The scanning of bar codes on tracked Lab property can be awkward in an environment where site access is limited and most of us are working remotely.  Download IBM BigFix, the Lab’s one-stop-shopping update tool for Macs and Windows PCs, and inventory reporting will be automatic.  Support will be easier, and patching of the highest-security-profile software will also be automated and more assured. You can choose an actively managed version or a passive version that notifies you of software updates but requires you to act on them manually. Go here to learn more about BigFix and download the right version for your situation (LBNL login required).


Virtual Tours of the Lab

Advanced Light Source dome

Facilities lay out virtual Welcome mat

Even the online holiday get-togethers of COVID times tend to make friends and relatives wonder what Berkeley Lab is like and what we do. The Lab has of course had to suspend in-person tours, but 90-minute virtual tours of our national user facilities— the Molecular Foundry, the Advanced Light Source, and the National Energy Research Scientific Computing Center—are ongoing and popular. (ATAP Outreach and Education Coordinator Ina Reichel is one of the ALS guides.) The virtual tours are free and open to anyone, but to ensure a quality experience, attendance at each session is limited and advance signup is required. As of this writing, January 12, January 22, and February 9 still have open slots.

Cultivating Future SAGEs of STEM

SAGE-S (Science Accelerating Girls' Engagement in STEM logo

Outreach volunteer opportunity

SAGE-S (Science Accelerating Girls’ Engagement in STEM) is a weeklong summer camp for public high school students (age 14-17). It is hosted by scientists and engineers who will share what everyday life is like in the STEM professions (Science, Technology, Engineering, and Mathematics). For summer 2021 Berkeley Lab will be hosting a virtual camp.

Here is the SAGE-S signup form. Additional information about the program will be shared at the Lab’s K-12 education website.


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

Felice Albert et al., including A. Huebl and J.-L. Vay (LBNL), “2020 Roadmap on Plasma Accelerators,” New Journal of Physics, in press December 2020,

Yuetao Hou, Sreyam Sinha, Di Ni (Cornell University); Qing Ji, Arun Persaud, Peter Seidl, Thomas Schenkel, (LBNL); Amit Lal, Khurram K. Afridi (Cornell University), “A 50-MHz Kilovolt-Scale Power Amplifier for Ion-Beam Accelerator Utilizing an Optimized Toroidal Inductor,” Proceedings of the IEEE Energy Conversion Congress and Exposition (ECCE), Detroit, MI, 11-15 October 2020, added to IEEE Xplore 30 October 2020, 10.1109/ECCE44975.2020.9236076

A. Huebl et al., “Spectral Control via Multi-Species Effects in PW-Class Laser-Ion Acceleration”, Plasma Physics and Controlled Fusion 62, 124003 (29 October 2020),

James K. Koga (Kansai Photon Science Institute); Masakatsu Murakami (Osaka University); Alexey V.Arefiev (University of California, San Diego); Yoshihide Nakamiya (ELI Nuclear Physics); Stepan S. Bulanov (LBNL); Sergei V.Bulanov (Kansai Photon Science Institute and ELI Beamlines) “Electron-Positron Pair Creation in the Electric Fields Generated by Micro-bubble Implosions”, Physics Letters A 384, 34 (4 December 2020), 126854,

T.M. Ostermayr (LBNL); C. Kreuzer, F. S. Englbrecht, J. Gebhard, J. Hartmann (Ludwig-Maximilians-Universität München); A. Huebl (LBNL); D. Haffa, P. Hilz, K. Parodi, J. Wenz (LMU-München); M.E. Donovan, G. Dyer, E. Gaul, J. Gordon, M. Martinez, E. Mccary, M. Spinks, G. Tiwari, B.M. Hegelich (University of Texas at Austin); J. Schreiber (LMU-München and Max-Planck-Institut für Quantenoptik), “Laser-driven x-ray and proton micro-source and application to simultaneous single-shot bi-modal radiographic imaging”, Nature Communications 11, 6174 (3 December 2020),
See feature story in this issue

V. Ranjan (CEA Saclay); J. O’Sullivan (University College London); E. Albertinale, B. Albanese (CEA Saclay); T. Chanelière (CNRS Grenoble); T. Schenkel (LBNL); D. Vion, D. Esteve, E. Flurin (CEA Saclay); J.J.L. Morton (University College London); P. Bertet (CEA Saclay), “Multimode storage of quantum microwave fields in electron spins over 100 ms,” Phys. Rev. Lett. 125, 210505 (20 November 2020),

Sreyam Sinha, Yuetao Hou, Di Ni (Cornell University); Qing Ji, Arun Persaud, Peter Seidl; T. Schenkel (LBNL); Amit Lal, Khurram K. Afridi (Cornell University), “A 27.12-MHz 10-kV Power Amplifier for Compact Particle Accelerators Utilizing an Optimized Matching Network,” Proceedings of the IEEE Energy Conversion Congress and Exposition (ECCE), Detroit, MI, 11-15 October 2020, added to IEEE Xplore 30 October 2020, pp. 5452-5457,

J.-L. Vay, A. Almgren, L.D. Amorim, J. Bell (LBNL); L. Ge (SLAC); K. Gott (LBNL); D.P. Grote (LLNL); M. Hogan (SLAC); A. Huebl, R. Jambunathan, R. Lehe, A. Myers (LBNL); C. Ng (SLAC); J. Park, M. Rowan, O. Shapoval, M. Thévenet, W. Zhang, Y. Zhao and E. Zoni (LBNL), “Toward the modeling of chains of plasma accelerator stages with WarpX,” in Proceedings of the 4th European Advanced Accelerator Concepts Workshop (15-20 September 2019, Isola d’Elba, Italy), Journal of Physics: Conference Series 1596, 012059 (18 September 2020) edited by A. Cianchi et al.,

Y. Zhao, R. Lehe, A. Myers, M. Thévenet, A. Huebl, C.B. Schroeder, J.-L. Vay, “Modeling of emittance growth due to Coulomb collisions in plasma-based accelerators”, Physics of Plasmas 27, 113105 (17 November 2020),

Invited talks without publication venue

S.S. Bulanov, “Multiple Colliding Laser Pulses as a Basis for Studying High-field High-energy Physics,” virtual ELI Beamlines User Conference 2020 (12-14 October 2020).

A. Huebl, “Future Computer & Programming Trends,” virtual talk, Snowmass21 Planning meeting. October 2020.

S.C. Leemann, “Machine Learning-based Beam Size Stabilization”, invited presentation at the 9th International Beam Instrumentation Conference IBIC 2020 (September 14-18, 2020, Brazil, virtual).

S.C. Leemann, “Source Size Stabilization at the ALS Using Machine Learning”, invited presentation at the 8th Low Emittance Rings Workshop LER2020 (October 26-30, 2020, INFN, Frascati, Italy, virtual).

J.-L. Vay and A. Huebl, “Uses of in situ methods in large-scale modeling of plasma-based particle accelerators,” keynote of the virtual ISAV 2020 workshop on In Situ Infrastructures for Enabling Extreme-Scale Analysis and Visualization (November 2020).


— Masking, distancing, and washing hands: keys to a COVID-19-free holiday


COVID-19 visualization courtesy CDC


As we go into the holiday season amid a resurgent COVID-19 crisis in California and nationwide, let’s renew our attention to the basics. Stay home whenever possible. When you must go out:
•  Wear a face covering (now a California requirement with limited exceptions)
•  Maintain at least 6 feet (preferably more) of social distancing
•  Pay attention to hand-washing and avoidance of face-touching…
…not just at work, but in all public places.

Going through life in this manner may feel tiresome, but this is no time to let our guard down. Diligence regarding these simple precautions is necessary to get through this and into a post-pandemic world of widespread vaccine deployment. For more information on how Berkeley Lab is prioritizing health and safety and what you can do, visit

COVID-19 precautions at the Lab

Berkeley Lab precautions for working onsite. Click for details.

Don’t Just Wear A Mask — Wear It Properly
This video from shows how to wear a mask properly to protect yourself and others. The Centers for Disease Control and Prevention also post the latest information on proper mask wearing and other best practices for stopping the spread of coronavirus.

Reminder: New Training Requirement Coming Up

A new training module, LBL 0014, “ISM Briefing for Return to Work” is now available. Though merely recommended at this point, at the end of January 2021 it will become mandatory for all staff.

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