Electron Beam Characterization of a High-Gradient X-Band Photoinjector

An X-band (8.548 GHz) rf photoinjector has been operated with a short pulse laser system to produce a high-brightness electron beam. The gun is designed to produce short (<1 ps) relativistic (5 MeV), low emittance (< π mm-mrad, at 0.1 nC) electron bunches. The Ti:Sapphire laser system consists of a 12 fs oscillator and a 50 fs regenerative amplifier (Spitfire system from Positive Light) operating at a wavelength of 800 nm and a repetition rate of 1 kHz. The light is subsequently frequency tripled. Detailed experimental measurements of the e^- beam are planned, and the following diagnostics are available: 5 MeV magnetic spectrometer, 1 ps resolution visible streak camera, Cherenkov imaging system, matched Faraday cup, and quadrupole scan. A low-flux Compton scattering experiment is also under development which will help characterize the beam emittance and energy spread. This work was performed under the auspices of the DOE by LLNL under contract No. W-7405-ENG-48, and partially supported by NIH Contract No. N01-CO-97113 and AFOSR MURI Grant No. F49620-99-1-0297.