LLNL’s laser-Compton team has demonstrated for the first time the generation of two nearly-identical high-charge electron bunches spaced by only one X-band (11.424-GHz) radio-frequency (RF) period. This milestone is a key component of LLNL’s three-year Laboratory Directed Research and Development (LDRD) project to validate the Laboratory’s patent-pending concepts for high-flux, mono-energetic x-ray and gamma-ray production. It was accomplished using the new state-of-the-art X-band accelerator test station in Bldg. 194, which is being developed to investigate accelerator optimization for future upgrades of LLNL’s laser-Compton light source technology.

 “This result puts LLNL at the forefront of international capabilities with respect to compact, high gradient accelerator R&D,” said NIF&PS Chief Technology Officer Chris Barty, “and has potential to fundamentally change the way in which Compton light sources are designed and optimized.”

The X-band laser-Compton test station in Bldg. 194. Team members examine various aspects of the X-band accelerator hardware in preparation for the next experiment. From left: Scott Anderson, Yoonwoo Hwang (UC Irvine), Shawn Betts, David Gibson and Gerry Anderson. Not pictured: Roark Marsh, Po-Chun Yeh (UC Irvine) and Scott Fisher.

      The X-band test stand is currently the only such capability in the world to combine both a high-stability, solid-state RF power source with a modern X-band accelerator structure and photo-gun. The ability to produce and accelerate multiple high-quality electron bunches paves the way for orders-of-magnitude increases in laser-Compton x-ray and gamma-ray output and has the potential to significantly impact both nuclear materials management missions and nuclear science studies based on mono-energetic gamma-rays, as well as novel medical and high-energy-density applications of laser-Compton x-rays.

The team includes researchers from both NIF & Photon Science and the Laboratory’s Physical and Life Sciences Directorate, as well as summer students from UC Irvine.