Demonstration of sub- GV / m accelerating field in a photoemission electron gun powered by nanosecond X -band radio-frequency pulses

• Published in: Physical review. Accelerators and beams Vol. 25; no. 8; p. 083402
• Main Authors: Tan, W. H., Antipov, S., Doran, D. S., Ha, G., Jing, C., Knight, E., Kuzikov, S., Liu, W., Lu, X., Piot, P., Power, J. G., Shao, J., Whiteford, C., Wisniewski, E. E.
• Format: Journal Article
• Language: English
• Published: College Park American Physical Society 01-08-2022; American Physical Society (APS)
• Subjects: Dark current; electron accelerator; Electron guns; Electron probes; Free electron lasers; high brightness; high gradient; PARTICLE ACCELERATORS; Photocathodes; Photoelectric emission; Radio frequency; Relativistic electron beams; short pulse; Superhigh frequencies
• ISSN: 2469-9888; 2469-9888
• DOI: 10.1103/PhysRevAccelBeams.25.083402

Radio-frequency (rf) photoemission electron guns operating at higher accelerating gradients offer a pathway to produce brighter electron bunches. Brighter beams are expected to revolutionize many areas of science: they could form the backbone of next-generation compact x-ray free-electron lasers or provide coherent ultrafast quantum electron probes. We report on the experimental demonstration of an rf photoemission electron source supporting an accelerating field close to400MV/mat the photocathode surface without major rf breakdown or significant dark current over a 3-week experimental run. This unprecedented gradient was achieved by operating the gun in a new regime with short rf pulses,∼9nsX-band (11.7 GHz). The demonstrated paradigm provides a viable path to form relativistic electron beams with unprecedented brightness.