From The DOE’s Lawrence Berkeley National Laboratory: “Upgraded Laser Facility Paves the Way for Next-Generation Particle Accelerators”

From The DOE’s Lawrence Berkeley National Laboratory

Alison Hatt

Accelerator Technology & Applied Physics Division scientists Marlene Turner and Anthony Gonsalves perform work on the laser table where the petawatt laser is split into the two beamlines. Well-positioned mirrors enable femtosecond overlap of the two lasers on target. (Credit: Marilyn Sargent/Berkeley Lab)

Researchers at Lawrence Berkeley National Laboratory (Berkeley Lab) have completed a major expansion of one of the world’s most powerful laser systems, creating new opportunities in accelerator research for the future of high-energy physics and other fields. The expansion created a second beamline for the petawatt laser at the Berkeley Lab Laser Accelerator (BELLA) Center, enabling the development of next-generation particle accelerators for applications in science, medicine, security, and industry. The second beamline came online this summer and is the culmination of several years of planning, design, and engineering by the BELLA and engineering teams.

“We are happy to see construction completed and are very eager to begin the wide variety of exciting experiments that are enabled by the second beamline,” said Eric Esarey, Director of the BELLA Center.

Using light to move particles

Traditional accelerators use radio-frequency electromagnetic fields to gradually speed particles up over distances of tens of kilometers and tend to be huge and very expensive as a result. For example, the Large Hadron Collider at CERN, the famous international particle accelerator, accelerates particles along a circular path over 16 miles long, a monumental achievement costing billions of dollars to build and operate.

At the BELLA Center, scientists accelerate charged particles with electric fields generated by a high-powered laser interacting with a plasma, creating what’s known as a laser-plasma accelerator (LPA). The team uses a one-petawatt laser that produces a beam of very short pulses or “bullets” of light, one per second, each of which is about a hundred times more powerful than a typical lightning bolt. When the laser beam passes through plasma (a gas-like soup of charged particles), it sets up a moving wave, and a charged particle placed in that wave is then propelled forward, like a surfer on an ocean wave. This “wakefield” approach can produce rates of acceleration up to one thousand times greater than conventional accelerators, making LPAs a promising candidate for the next generation of smaller, less expensive accelerators.

A powerful tool for accelerator technology development

The second beamline was designed to be highly tunable, able to produce a wide range of laser-spot sizes, with pulse durations and pulse energies that can be varied independently. The two beamlines are intended to be used in tandem, making the system a powerful and versatile tool for science and accelerator technology development. To create the new beamline, the team split off a portion of the main laser beam and ran it through a series of optics to generate a second beam of short, powerful pulses of light that can create a second wakefield.

In particular, the system was designed to enable the team’s vision of staging multiple LPA modules in order to reach the high electron-beam energies needed for particle colliders, using the wakefield of the second beamline to further accelerate particles coming off the first. Initial experiments to achieve this goal are currently underway. In their longer-term vision, the team proposes stacking additional laser-powered modules to create accelerators of extremely high energies, enabling the next generation of physics discoveries at a fraction of the cost and size.

As an example, methods to enhance the energy efficiency of LPAs can also be explored with the dual beamlines. The second beamline laser pulse can be configured to absorb any leftover energy in the first beamline plasma that is unused by the acceleration process and then sent to an energy recovery system. Marlene Turner, a scientist in the BELLA Center, received a prestigious early career award from DOE to work on this concept. “Without the second beamline, my research, which aims to decrease the power consumption and environmental impact of future plasma colliders, would not be possible,” said Turner.

The dual beamlines can be used in other configurations as well. For example, the second beamline can be used to accelerate particles to scatter off those from the first beamline, enabling physicists to probe the exotic physics that arise.

“The precision that these two laser beamlines bring, combining femtosecond timing and micron-scale spatial accuracy, is unprecedented at petawatt-class peak power levels, and will enable experiments on LPA staging as well as other advances in plasma acceleration such as laser tailoring of plasma accelerating structures, laser-based methods of particle injection, high energy photon production by laser scattering, and fundamental studies in high field quantum electrodynamics, ” said Tony Gonsalves, the lead scientist on the BELLA petawatt team. “It’s a big deal.”

(Left): Two deformable mirrors. In addition to arrival time and pulse length control of both beam lines, these mirrors allow for independently shaping the focal spot mode, which is critical for optimized staged acceleration. (Right) In the newly-commissioned second beam line, the laser beam travels through the large white tubes into the laser-plasma accelerator vacuum system. Marlene Turner (foreground) and postdoctoral scholar Alex Picksley check for alignment. (Credit: Marilyn Sargent/Berkeley Lab)

The power of team science

Berkeley Lab is known as a powerhouse of team science, and this new BELLA project exemplified this ethos. At any one time, the core team working on this project includes ten to fifteen mechanical engineers, electrical engineers, and research scientists, as well as a rotating cast of other key players, including radiological safety specialists and seismic engineers. This has ensured that the two-laser-beamline upgrade not only creates state of the art science, but is executed in a safe, well-engineered, and durable manner that will enable continued productivity for many years to come.

The team encountered their fair share of challenges due to the COVID-19 pandemic, which temporarily shut their facility down. After it reopened, the team had to work in shifts, using a ticketing system to maintain safe density of workers. Just bringing in a team of French engineers to install a compressor chamber took the better part of a year due to pandemic-related restrictions.

“It’s been a long road to get this going, and a much longer road because of COVID,” said Gonsalves. “If you were to count how many people have touched this project, it’d be a very large number. We’re lucky to have this impressive infrastructure of people at the Lab to make a project like this possible.

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Bringing Science Solutions to the World

In the world of science, The Lawrence Berkeley National Laboratory (Berkeley Lab) is synonymous with “excellence.” Thirteen Nobel prizes are associated with Berkeley Lab. Seventy Lab scientists are members of the The National Academy of Sciences, one of the highest honors for a scientist in the United States. Thirteen of our scientists have won the National Medal of Science, our nation’s highest award for lifetime achievement in fields of scientific research. Eighteen of our engineers have been elected to the The National Academy of Engineering, and three of our scientists have been elected into the Institute of Medicine. In addition, Berkeley Lab has trained thousands of university science and engineering students who are advancing technological innovations across the nation and around the world.

Berkeley Lab is a member of the national laboratory system supported by the U.S. Department of Energy through its Office of Science. It is managed by the University of California and is charged with conducting unclassified research across a wide range of scientific disciplines. Located on a 202-acre site in the hills above the University of California- Berkeley campus that offers spectacular views of the San Francisco Bay, Berkeley Lab employs approximately 3,232 scientists, engineers and support staff. The Lab’s total costs for FY 2014 were $785 million. A recent study estimates the Laboratory’s overall economic impact through direct, indirect and induced spending on the nine counties that make up the San Francisco Bay Area to be nearly $700 million annually. The Lab was also responsible for creating 5,600 jobs locally and 12,000 nationally. The overall economic impact on the national economy is estimated at $1.6 billion a year. Technologies developed at Berkeley Lab have generated billions of dollars in revenues, and thousands of jobs. Savings as a result of Berkeley Lab developments in lighting and windows, and other energy-efficient technologies, have also been in the billions of dollars.

Berkeley Lab was founded in 1931 by Ernest Orlando Lawrence, a University of California-Berkeley physicist who won the 1939 Nobel Prize in physics for his invention of the cyclotron, a circular particle accelerator that opened the door to high-energy physics. It was Lawrence’s belief that scientific research is best done through teams of individuals with different fields of expertise, working together. His teamwork concept is a Berkeley Lab legacy that continues today.



The laboratory was founded on August 26, 1931, by Ernest Lawrence, as the Radiation Laboratory of the University of California-Berkeley, associated with the Physics Department. It centered physics research around his new instrument, the cyclotron, a type of particle accelerator for which he was awarded the Nobel Prize in Physics in 1939.

LBNL 88 inch cyclotron.

LBNL 88 inch cyclotron.

Throughout the 1930s, Lawrence pushed to create larger and larger machines for physics research, courting private philanthropists for funding. He was the first to develop a large team to build big projects to make discoveries in basic research. Eventually these machines grew too large to be held on the university grounds, and in 1940 the lab moved to its current site atop the hill above campus. Part of the team put together during this period includes two other young scientists who went on to establish large laboratories; J. Robert Oppenheimer founded The DOE’s Los Alamos Laboratory, and Robert Wilson founded The DOE’s Fermi National Accelerator Laboratory.


Leslie Groves visited Lawrence’s Radiation Laboratory in late 1942 as he was organizing the Manhattan Project, meeting J. Robert Oppenheimer for the first time. Oppenheimer was tasked with organizing the nuclear bomb development effort and founded today’s Los Alamos National Laboratory to help keep the work secret. At the RadLab, Lawrence and his colleagues developed the technique of electromagnetic enrichment of uranium using their experience with cyclotrons. The “calutrons” (named after the University) became the basic unit of the massive Y-12 facility in Oak Ridge, Tennessee. Lawrence’s lab helped contribute to what have been judged to be the three most valuable technology developments of the war (the atomic bomb, proximity fuse, and radar). The cyclotron, whose construction was stalled during the war, was finished in November 1946. The Manhattan Project shut down two months later.


After the war, the Radiation Laboratory became one of the first laboratories to be incorporated into the Atomic Energy Commission (AEC) (now The Department of Energy . The most highly classified work remained at Los Alamos, but the RadLab remained involved. Edward Teller suggested setting up a second lab similar to Los Alamos to compete with their designs. This led to the creation of an offshoot of the RadLab (now The DOE’s Lawrence Livermore National Laboratory) in 1952. Some of the RadLab’s work was transferred to the new lab, but some classified research continued at Berkeley Lab until the 1970s, when it became a laboratory dedicated only to unclassified scientific research.

Shortly after the death of Lawrence in August 1958, the UC Radiation Laboratory (both branches) was renamed the Lawrence Radiation Laboratory. The Berkeley location became the Lawrence Berkeley Laboratory in 1971, although many continued to call it the RadLab. Gradually, another shortened form came into common usage, LBNL. Its formal name was amended to Ernest Orlando Lawrence Berkeley National Laboratory in 1995, when “National” was added to the names of all DOE labs. “Ernest Orlando” was later dropped to shorten the name. Today, the lab is commonly referred to as “Berkeley Lab”.

The Alvarez Physics Memos are a set of informal working papers of the large group of physicists, engineers, computer programmers, and technicians led by Luis W. Alvarez from the early 1950s until his death in 1988. Over 1700 memos are available on-line, hosted by the Laboratory.

The lab remains owned by the Department of Energy , with management from the University of California. Companies such as Intel were funding the lab’s research into computing chips.

Science mission

From the 1950s through the present, Berkeley Lab has maintained its status as a major international center for physics research, and has also diversified its research program into almost every realm of scientific investigation. Its mission is to solve the most pressing and profound scientific problems facing humanity, conduct basic research for a secure energy future, understand living systems to improve the environment, health, and energy supply, understand matter and energy in the universe, build and safely operate leading scientific facilities for the nation, and train the next generation of scientists and engineers.

The Laboratory’s 20 scientific divisions are organized within six areas of research: Computing Sciences; Physical Sciences; Earth and Environmental Sciences; Biosciences; Energy Sciences; and Energy Technologies. Berkeley Lab has six main science thrusts: advancing integrated fundamental energy science; integrative biological and environmental system science; advanced computing for science impact; discovering the fundamental properties of matter and energy; accelerators for the future; and developing energy technology innovations for a sustainable future. It was Lawrence’s belief that scientific research is best done through teams of individuals with different fields of expertise, working together. His teamwork concept is a Berkeley Lab tradition that continues today.

Berkeley Lab operates five major National User Facilities for the DOE Office of Science:

The Advanced Light Source (ALS) is a synchrotron light source with 41 beam lines providing ultraviolet, soft x-ray, and hard x-ray light to scientific experiments.

The DOE’s Lawrence Berkeley National Laboratory Advanced Light Source.
The ALS is one of the world’s brightest sources of soft x-rays, which are used to characterize the electronic structure of matter and to reveal microscopic structures with elemental and chemical specificity. About 2,500 scientist-users carry out research at ALS every year. Berkeley Lab is proposing an upgrade of ALS which would increase the coherent flux of soft x-rays by two-three orders of magnitude.

Berkeley Lab Laser Accelerator (BELLA) Center

The DOE Joint Genome Institute supports genomic research in support of the DOE missions in alternative energy, global carbon cycling, and environmental management. The JGI’s partner laboratories are Berkeley Lab, DOE’s Lawrence Livermore National Laboratory, DOE’s Oak Ridge National Laboratory (ORNL), DOE’s Pacific Northwest National Laboratory (PNNL), and the HudsonAlpha Institute for Biotechnology . The JGI’s central role is the development of a diversity of large-scale experimental and computational capabilities to link sequence to biological insights relevant to energy and environmental research. Approximately 1,200 scientist-users take advantage of JGI’s capabilities for their research every year.

LBNL Molecular Foundry

The LBNL Molecular Foundry is a multidisciplinary nanoscience research facility. Its seven research facilities focus on Imaging and Manipulation of Nanostructures; Nanofabrication; Theory of Nanostructured Materials; Inorganic Nanostructures; Biological Nanostructures; Organic and Macromolecular Synthesis; and Electron Microscopy. Approximately 700 scientist-users make use of these facilities in their research every year.

The DOE’s NERSC National Energy Research Scientific Computing Center is the scientific computing facility that provides large-scale computing for the DOE’s unclassified research programs. Its current systems provide over 3 billion computational hours annually. NERSC supports 6,000 scientific users from universities, national laboratories, and industry.

DOE’s NERSC National Energy Research Scientific Computing Center at Lawrence Berkeley National Laboratory.

Cray Cori II supercomputer at National Energy Research Scientific Computing Center at DOE’s Lawrence Berkeley National Laboratory, named after Gerty Cori, the first American woman to win a Nobel Prize in science.

NERSC Hopper Cray XE6 supercomputer.

NERSC Cray XC30 Edison supercomputer.

NERSC GPFS for Life Sciences.

The Genepool system is a cluster dedicated to the DOE Joint Genome Institute’s computing needs. Denovo is a smaller test system for Genepool that is primarily used by NERSC staff to test new system configurations and software.

NERSC PDSF computer cluster in 2003.

PDSF is a networked distributed computing cluster designed primarily to meet the detector simulation and data analysis requirements of physics, astrophysics and nuclear science collaborations.

Cray Shasta Perlmutter SC18 AMD Epyc Nvidia pre-exascale supercomputer.

NERSC is a DOE Office of Science User Facility.

The DOE’s Energy Science Network is a high-speed network infrastructure optimized for very large scientific data flows. ESNet provides connectivity for all major DOE sites and facilities, and the network transports roughly 35 petabytes of traffic each month.

Berkeley Lab is the lead partner in the DOE’s Joint Bioenergy Institute (JBEI), located in Emeryville, California. Other partners are the DOE’s Sandia National Laboratory, the University of California (UC) campuses of Berkeley and Davis, the Carnegie Institution for Science , and DOE’s Lawrence Livermore National Laboratory (LLNL). JBEI’s primary scientific mission is to advance the development of the next generation of biofuels – liquid fuels derived from the solar energy stored in plant biomass. JBEI is one of three new U.S. Department of Energy (DOE) Bioenergy Research Centers (BRCs).

Berkeley Lab has a major role in two DOE Energy Innovation Hubs. The mission of the Joint Center for Artificial Photosynthesis (JCAP) is to find a cost-effective method to produce fuels using only sunlight, water, and carbon dioxide. The lead institution for JCAP is the California Institute of Technology and Berkeley Lab is the second institutional center. The mission of the Joint Center for Energy Storage Research (JCESR) is to create next-generation battery technologies that will transform transportation and the electricity grid. DOE’s Argonne National Laboratory leads JCESR and Berkeley Lab is a major partner.