Optical beam profile diagnostic for low energy, long pulse, moderate current electron beams

• Published in: Review of scientific instruments 2006-03, Vol.77 (3), p.033302-033302-7
• Main Authors: Russell, Steven J., Wang, Zhi-Fu, Haynes, W. Brian, Carlsten, Bruce E., Earley, Lawrence M.
• Format: Article
• Language: English
• Subjects: BEAM PROFILES; BREMSSTRAHLUNG; CRYSTALS; DENSITY; ELECTRON BEAMS; ELECTRON GUNS; ELECTRON SOURCES; ELECTRONS; FOILS; GHZ RANGE 100-1000; LANL; METALS; PARTICLE ACCELERATORS; PULSES; TRAVELLING WAVE TUBES; X RADIATION
• ISSN: 0034-6748; 1089-7623
• DOI: 10.1063/1.2173028

Currently ongoing at Los Alamos National Laboratory is a program to develop high-power, planar 100 - 300 GHz traveling-wave tubes. An enabling technology for this effort is a sheet electron beam source and much of our effort has been geared toward understanding sheet beam generation and transport. Toward this end we have developed a robust, high resolution optical diagnostic for measuring the transverse density profiles of our electron beams. The diagnostic consists of a thin metal foil followed by an YAG : Ce or YAP : Ce scintillator crystal, both mounted on a vacuum actuator that allows us to position the foil/scintillator combination at arbitrary positions along the beam's longitudinal axis. The electron beam strikes the metal foil and is stopped, generating Bremsstrahlung x rays that are imaged by the scintillator crystal. This image is then captured by an optical system using a high-speed, intensified gated camera. Using this diagnostic, we have measured beam profiles with resolutions as low as 0.05 mm from a 0.51 μ P electron gun operated between 20 and 120 kV .