I earned my degrees at Goethe University in Frankfurt, Germany, doing my graduate research at Lawrence Livermore National Laboratory on ion-solids interactions. In a postdoctoral fellowship there, I researched ultrafast (~10 fs) electronic excitation of solids, nanostructuring (“nano” was new then), and materials analysis. In 2000, I came to Berkeley Lab to work on the “front-end system” that the Accelerator and Fusion Research Division (now known as ATAP) was developing for the Spallation Neutron Source being built at Oak Ridge. Here is a link to my CV for those interested in the details.

During those days I also began work on the hardware foundations of quantum computing, exploring spin qubit ideas — work that continues, and is now aligned with a burgeoning Labwide emphasis on quantum information systems. (To learn more about this, see the related article, and visit the Berkeley Quantum website.) My other research interests include materials far from equilibrium (as studied, for example, with intense ion beam pulses and plasmas) and novel accelerator concepts (such as MEMS-based multi-beam accelerators).

Later years brought opportunities to lead the Ion Beam Technology Group, then to serve as head of the Fusion Science and Ion Beam Technology Program. Throughout my time at the Lab I have been fortunate to be able to work with many colleagues in ATAP and our partners in the Engineering Division as well as with colleagues across the Lab.

The generation and ensuing acceleration of ion beams is one of the central legacies of the Division’s (and Berkeley Lab’s) origins. Driving advanced accelerator concepts (most notably based on laser-plasma acceleration in the BELLA Center) and the development and application of ion sources, compact accelerators and low-energy accelerator “front ends” has continued to be an area of excellence for us.

I have always been attracted to the idea of the scientist as a maverick who likes to learn and try new things. And I have learned that innovation and creativity can be balanced with long term vision and the discipline to complete things.

Teaching a graduate course on Accelerators and Beam Physics in UC-Berkeley’s Nuclear Engineering Department last Spring, together with Carl Schroeder, proved to be a lot more fun then I had expected (all these slides to prepare…) and I see a really wonderful opportunity here to foster and grow our longstanding connection with new joint projects and students from campus who work with us.

As is required for cutting-edge work in accelerators, we are very good at many different things, and what’s more, we talk to each other. Cross-pollination among our specialty areas is something that benefits both our own endeavors and our many collaborations (across the lab, with campus, nationally and internationally). As interim director, I look forward to finding new ways to foster this success pattern.

“In the search for an interim director, we were looking for someone who exemplified Berkeley Lab’s approach to team science and appreciated the whole of the accelerator field. Thomas brings a rigorous technical knowledge that is broad as well as deep, and a history of collaborative work with enthusiasm for disruptive ideas.”
—ALD for Physical Sciences James Symons

In ATAP, we are laying the scientific foundations of future particle accelerators. These accelerators can make the difference in advancing our understanding of the most fundamental aspects of matter and energy in the universe and they enable exciting new applications.

In ATAP, theory, modeling and simulations iterate swiftly with experiments to drive advanced accelerator concepts. We are leading the world in mastery of laser-driven plasmas that accelerate electrons to record energies at the BELLA Center. We are developing near-term, high-impact applications of laser-plasma accelerators in areas ranging from radiography to medicine. Coherent combining of fiber laser pulses might be the ticket to reaching high average power with short pulse lasers. Ultrafast electron diffraction at MHz repetition rates (HiRES) now enables collaborative users to track the multi-scale structural evolution of materials. ATAP plays key accelerator physics and technology roles in the ALS-U project, the upgrade of Berkeley Lab’s Advanced Light Source that will serve thousands of users for years to come. We are pushing the envelope in magnet development to reach higher fields with new materials and are leading the US Magnet Development Program. We use lasers, plasmas and beams to drive materials and matter far from and study novel properties under these extreme conditions — now with users and collaborators as part of LaserNetUS (see article below). We apply beams of neutrons to image carbon in soil. We develop multi-beam ion accelerators based on MEMS that might enable massive scaling of beam power in a table top setup. We use and develop machine-learning techniques to advance accelerator science, and we have connected to the new wave of Quantum Information Science with precision control techniques and new ideas on spins and photons for quantum sensing and communication.

Throughout our diverse endeavors in accelerator technology and applied physics, a key to our success is the ability to integrate our capabilities in theory, modeling and simulation, and fabrication and operation of facilities. Supporting all this, we are fortunate to have strong and dedicated technical-support and business-operations teams so we can work efficiently and safely.

I very much look forward to this opportunity. I am excited about working with you, supporting ongoing programs, and helping to develop the seeds of new ideas into new and thriving R&D directions.

Eric Esarey has been performing research on intense laser-plasma interactions, advanced accelerator concepts and novel radiation sources for over 30 years. After receiving his PhD in 1986 in plasma physics at MIT, he worked for 12 years at the Naval Research Laboratory. During that time, he and his colleagues pioneered fundamental theory on nonlinear laser-plasma interactions that described the physics of laser-plasma accelerators (LPAs) and carried out groundbreaking experiments on LPAs.

Esarey joined Berkeley Lab in 1998 as a physicist within the theory group of the Center for Beam Physics, where he continued researching LPAs and related phenomena. He helped found the BELLA Center and grow it into the world leading program that it is today. Esarey had previously served as BELLA Center’s Deputy and as Senior Scientific Advisor to the ATAP Division Director. He now succeeds BELLA’s founding director, Wim Leemans, who has left LBNL for a position at DESY.

Schenkel describes Esarey as “a visionary and longtime leader in the field of LPAs with an integrating perspective on the program.”

Esarey’s recent honors include the AAC Prize from the 2018 Advanced Accelerator Concepts Workshop (an event that he will chair in 2020). Among his numerous publications are comprehensive review articles on plasma accelerators that are highly cited within the community. A technical backgrounder accompanying the announcement 2018 Nobel Prize in Physics explained the LPA concept with a diagram originally published in Physics Today by Leemans and Esarey. (See the related article, “2018 Physics Nobel Cites an ATAP Application.”)

Esarey’s deputies are described by Schenkel as “capable, energetic, and with diverse scientific backgrounds,” exemplars of a strong BELLA team “hungry for achievement.”

Carl Schroeder has been a leader of the theoretical and modeling efforts that support BELLA’s experimental work and future applications. After earning his doctorate at UC-Berkeley in 1999, followed by a postdoctoral fellowship at UCLA, he joined LBNL in 2001. His research interests range across BELLA’s intellectual portfolio, including intense laser-plasma interactions, plasma-based accelerators, advanced acceleration concepts, novel radiation sources, and free-electron lasers. “Carl is a theoretical leader not only in BELLA’s current work, but also in the long-term push toward an LPA-based lepton collider,” says Schenkel.

“Ultimately,” he adds, “mastery of laser drive plasma accelerators will enable us to explore physics beyond the Standard Model, and to make strides in understanding the nature of matter and energy, and do so with a much smaller physical and financial footprint than today’s collider technologies. Carl is driving this vision and is laying the foundation for its practical implementation.”

Cameron Geddes is the lead experimentalist in the new BELLA Center leadership team.

“Cameron has a very strong foundation in high-energy and ultrafast lasers, and since his days as a graduate student has been a driving force and leader in the projects he works on,” says Schenkel.

Geddes has led a variety of the Center’s experimental projects. This includes a new laser facility for one of the many promising near-term applications of laser-plasma accelerators: compact quasi-monoenergetic gamma-ray sources for nuclear nonproliferation and security inspection. He has broad research experience in plasma physics, which at Berkeley Lab has included experimental designs for the PW laser, demonstration of novel concepts in particle injection and beam quality, staging experiments, high energy density science, and large-scale simulations. After working at Lawrence Livermore National Laboratory and Polymath Research on inertial-fusion-related laser-plasma interactions, he earned his doctorate at UC-Berkeley and LBNL in 2005, receiving the Hertz and APS Rosenbluth dissertation prizes. He joined the LBNL staff upon graduation. “Cameron brought a strong foundation in high-energy and ultrafast lasers to us, and since his days as a graduate student has always been a leader in everything he works on,” says Schenkel.

The path forward

BELLA Center is a world leader in the study of intense laser-plasma interactions and advancing the development of LPAs. Research there has demonstrated increasing single-stage electron beam energy gains, now at several GeV, together with lower-energy experiments on staging and on achieving high beam quality.

Going to ever higher energies will require using one LPA stage’s output as the input to the next, achieving more energy than is practical for a single stage. BELLA has achieved a first demonstration of staging. A major next step is to develop and implement a multi-GeV staging experiment. This very exciting and important effort has now been started with funding from DOE High Energy Physics.

In addition to electron beam acceleration, BELLA is exploring the applications of laser-plasma accelerated electron beams, e.g., with programs to develop compact radiation sources based on LPA electron beams.

Higher average laser power will be required for a lepton collider and also for many near-term LPA applications, and the BELLA Center is performing R&D to advance the development of these lasers. Fiber-based laser systems are among the candidates for this key enabling technology.

“Eric, Cameron, and Carl are all distinguished individuals and team leaders in their disciplines, and have been working together for many years to keep BELLA at the forefront of laser-plasma acceleration,” Schenkel says, adding, “BELLA is sure to enjoy continued growth and achievement under their leadership.”

Tour guides from ATAP who have specific knowledge of the ALS are especially needed. (Particle accelerators, with their ongoing rich heritage of contributions to our knowledge of the atom, nucleus, and subatomic particles, are regarded as nuclear facilities for merit-badge purposes, and the Advanced Light Source is the focus of many of their experiences.)

However, you don’t need to be a scientist or engineering and technology professional to contribute to Nuclear Science Day for Scouts. Logistics and chaperoning are key parts of a good experience, so come help the Scouts learn that people from all walks of life play many positions in team science.

To learn more…
• Visit the Nuclear Science Day for Scouts website. The site also has a link for Scout leaders to sign up their troop. (Note: If you’re involved in Scouting, signing up as a volunteer increases the likelihood that your troop will be among those accepted for this space-limited and significantly oversubscribed event.)
• You can also learn more through this Berkeley lab photostory and sign up for the event’s Twitter feed.
• Contact Ina Reichel, ATAP’s Education and Outreach Coordinator, for more information about volunteering.
• The signup form for volunteers can be found here.