Two technicians in cleanroom attire assemble the large, round, copper colored injector gun for the LCLS-II electron source

Parts of the electron gun for the LCLS-II injector are assembled in a Berkeley Lab cleanroom. The unprecedented performance demands of the injector were a natural fit for our Advanced Photoelectron Experiment (APEX) R&D. The work also led to our HiRES facility for ultrafast electron diffraction.

The Linac Coherent Light Source II (LCLS-II) project at SLAC is a prime example of how team science rises to large-scale challenges. Several institutions collaborated to build this major upgrade to SLAC’s X-ray free-electron laser facility.

ATAP and the Engineering Division were responsible for two major deliverables: the injector source, which provides electrons, and the undulator segments, which cause the electron beam to take an undulating path, emitting photons for the soft and hard X-ray beamlines. We also contributed to beam-dynamics modeling and low-level radiofrequency (LLRF) control systems.

Accelerator facilities are often upgraded as technology advances and new ideas are introduced. As LCLS-II proceeds through commissioning and initial science, the LCLS-II High Energy upgrade project (LCLS-II-HE) is already underway. For this project, the superconducting accelerator energy will be doubled from 4 GeV to 8 GeV. To maintain the desired soft x-ray spectral range, new magnetic components for the soft x-ray (SXR) undulators, with a longer wavelength for the magnetic undulations, are required. Reprising one of our key roles in LCLS-II, Berkeley Lab is responsible for designing and manufacturing new undulator components for LCLS-II-HE.

Full undulator (left) and magnetic components (right) for the updated LCLS-II-HE Soft X-Ray undulators.

Some minor modifications are also being made to the existing undulator mechanical system to accommodate the higher magnetic force of the new magnetic components. We are tasked with delivering nine new SXR undulators and the components to update 21 existing SXR LCLS-II undulators at SLAC.

Together with SLAC, Berkeley Lab engineers built the LLRF controls system for LCLS-II, including system architecture, hardware, firmware and software. We continue to work on LCLS-II-HE and on improvement of controls for the normal-conducting electron gun. As with LCLS-II, we also contribute to the LCLS-II-HE project through beam-dynamics modeling.