Berkeley Lab

Center for Beam Physics: More Information

Incubator of new concepts and technologies for LBNL, DOE, and beyond

Highly collaborative and interdisciplinary, CBP is a central resource for theoretical and experimental innovation serving the accelerator community. Maximizing the science reach of proton accelerators at the frontiers of energy and intensity, and exploring x-ray free-electron lasers, are major themes of our research. CBP staff have wide-ranging expertise in accelerator theory and design, instrumentation, diagnostics, RF hardware, and experimental accelerator physics. An ever more important capability — synergistic with other LBNL strengths and widely useful to the accelerator community — is advanced simulation and modeling.

Our goal is to understand the performance limitations of today’s accelerators and to provide optimal solutions to extend the energy, luminosity, and intensity frontiers in the future. We collaborate closely with other national laboratories and institutions, and with other programs within ATAP and elsewhere in LBNL, notably the Engineering Division. We have been involved from the beginning in the ongoing US-LARP (LHC Accelerator R&D) collaboration.

Although the energy frontier in operating accelerators passed to Europe after the Fermilab Tevatron gave way to the LHC, there is still a great deal of interest in energy-frontier facilities that could be built in the US. Accordingly, we are involved in R&D and design studies for future accelerators such as PIP-II, a Neutrino Factory, and a Muon Collider.

CBP staff have made significant contributions to the development concepts for a muon collider and neutrino factory,providing theoretical analysis and understanding of cooling channel performance and developing a practical tool for calculating the 6D emittance of a simulated distribution. CBP staff have leadership roles in muon-accelerator R&D in the areas of design and simulation, as well as RF systems.

Accelerator Systems and Hardware

Advanced hardware, particularly in diagnostic and control systems, is a longtime area of strength for the Center, going back to our earliest origins as the Beam Cooling Group. We provide hardware components and systems for accelerator R&D in areas that include

  • Instrumentation and diagnostics.
  • Beam cooling and feedback systems.
  • Low-impedance structures (monochromatic RF cavities, crab cavities, bellows, vacuum chamber transitions, etc.).
  • High-gradient RF cavities with the goal of exploring the limits of RF breakdown under a variety of conditions.

Accelerator “Front Ends”: RFQs and Beam Transport Systems

IMP-RFQ-group-photo_250Another of our key responsibilities — going back to ATAP’s deep origins in the Bevalac accelerator complex — is service to ion-accelerator-based projects in the Department of Energy and elsewhere. Thanks in large part to our work on the multi-laboratory Spallation Neutron Source (SNS) team, we have helped LBNL come to be regarded as the laboratory of choice for the technically challenging “front end” of an ion accelerator: the series of initial components that give a beam the highest-quality start. We stand ready to contribute to other national research priorities that can take advantage of these capabilities, such as a proton driver for neutrino experiments at Fermilab.

A particular area of expertise in ATAP is the radiofrequency quadrupole accelerator, or RFQ. Together with our colleagues in the Engineering Division, we have been designing and building RFQs for some 30 years. Recently we developed an RFQ of demanding specifications for the Institute of Modern Physics in Lanzhou, China. The RFQ will be a key part of a system that they are developing to transmute reactor waste into shorter-lived forms. This unit achieved 10 mA of beam current at 2.1 MeV this November in Lanzhou, making it the highest-intensity RFQ in operation. See also the December 2014 issue of the ATAP Newsletter.

We are also working on a similar RFQ for PIP-II, the Proton Improvement Plan at Fermilab, a centerpiece of their plans for high-energy and nuclear-physics research. This RFQ is expected to be delivered in 2015.

Femtosecond Timing Distribution

A area of special expertise is high-precision fiber-optic distributed timing and synchronization systems that can operate across wide areas. Though the fundamental idea had been invented elsewhere, LBNL brought unique innovations and a high degree of development to this system. Its femtoseconds-across-kilometers capability has proved especially useful for Basic Energy Sciences facilities, notably the Linac Coherent Light Source at SLAC National Accelerator Laboratory, and LCLS-II, which is now being planned with substantial LBNL involvement.

Modeling and Simulation: BLAST and CAMPA

boostedframe_250pxDesigning accelerators and their upgrades is critically dependent on advanced modeling and simulation. In LBNL’s Accelerator and Fusion Research Division (and in particular the Center for Beam Physics), these efforts are finding synergies through the Berkeley Lab Accelerator Simulation Toolkit (BLAST) program. Building upon that base, we are now leading an emergent collaborative effort called CAMPA, the Consortium for Advanced Modeling of Particle Accelerators. Bringing together efforts by ourselves, SLAC National Accelerator Laboratory, and Fermilab, the proposed CAMPA will support the DOE’s mission by developing, maintaining, distributing, and supporting advanced computational tools for accelerator and beam physics.

The uses of these codes are as diverse as accelerators themselves. Simulation helps us design and understand all types of accelerators &#151 linacs and storage rings for leptons or hadrons or ions with multiple charge states &#151 and all parts of the system-of-systems that is a modern accelerator facility, from injectors through transfer lines and into storage rings. Novel approaches such as laser-plasma accelerators, and devices with related physics such as ion traps, also benefit.

Throughout, we seek greater fidelity as proven analytically and through experimental benchmarking; higher efficiency so that greater detail can be achieved with the computational resources available to users; and enhancement and integration of codes for ever more comprehensive multiphysics modeling. Development of innovative algorithms, as well as realizing them in software, is key to our efforts.

Berkeley Lab is a natural site for this effort. Some 80 years after its founder and namesake invented the cyclotron, the laboratory remains a leader in particle-accelerator R&D. It is also home to a pair of invaluable central resources for modeling and simulation: a strong and highly collaborative computational research division, and the National Energy Research Supercomputing Center.

The results benefit a wide variety of fields extending across much of the DOE Office of Science research portfolio and beyond. Accelerators are still key to exploring the fundamental nature of the universe, but today they do far more. The particle and photon beams that they provide have become tools for for many other fields of science and technology, and practical applications have co-evolved with the machines themselves and improve our day-to-day lives in a great many ways. Using computational techniques to build better accelerators is an activity whose benefits have high multipliers and broad benefits to the research community and thence to society.

Accelerator Theory

Fundamental not only to simulation but to all of these efforts is a theoretical understanding of acceleration and beam physics. Increasing this understanding of beam physics is critical to developing advanced accelerator capabilities. The CBP has leading expertise in electron-cloud effects and other phenomena which have the potential to reduce accelerator performance or to limit future upgrades. In addition to developing better models for microbunching, coherent synchrotron radiation and space charge, techniques to suppress their impact have been proposed.

Recent CBP Publications

Please visit the ATAP publications page for a full list of 2014 journal articles and other publications associated with the Center for Beam Physics.