End view of copper colored RFQ linac

This Berkeley Lab radiofrequency quadrupole (RFQ) linear accelerator is a crucial part of Fermilab’s Proton Improvement Plan II (PIP-II), a major upgrade to their accelerator complex. (Photo courtesy Andrew Lambert.)

Most particle accelerators impart energy to the beam with electric fields set up by radiofrequency (RF) power inside resonant structures. In the BACI Program, we use this expertise for some of the world’s most challenging accelerator-based projects.

Over the past three decades, we have developed and delivered several demanding ion-accelerator “front ends,” including units for the Spallation Neutron Source and a recent radiofrequency-quadrupole linac for Fermilab’s PIP-II project.

Studying and mitigating the deleterious effects of beam impedance—the interaction of the fields of an intense beam with the vacuum chamber and accelerator components—is another of our longtime strengths. We have recently applied this work to upcoming projects such as ALS-U, the upgrade to Berkeley Lab’s Advanced Light Source. Advanced computation techniques, like multi-objective genetic algorithms, increasingly factor into such work.

End view of a cylindrical chamber containing an advanced electron injector.

State-of-the-art physics and engineering went into the electron gun for the LCLS-II injector source.

In recent years, Berkeley Lab has developed a unique capability in developing normal-conducting accelerating structures for continuous (CW) acceleration, hitherto the province of more expensive superconducting cavities. We have also become a leader in the design of broadband RF structures, such as kickers for fast beam manipulation, which is key to ALS-U and other future projects.

Ultrafast sources of high-quality electron beams are another capability of recent years—vital to LCLS-II, the Linac Coherent Light Source upgrade, a major DOE user facility built by a multi-institutional team at SLAC National Accelerator Laboratory. The effort already provides a spinoff application in the form of Berkeley Lab’s HiRES tool for ultrafast electron diffraction. Meanwhile, anticipating the needs of future LCLS-II upgrades and other facilities, we are working on a next-generation version.