Development of a high current electron gun to generate single-bunch beams with the L-band linear accelerator in Osaka University

A high current electron gun using a cathode-grid assembly was developed to generate high intensity single-bunch electron beams with the L-band linear accelerator in the Institute of Scientific and Industrial Research, Osaka University. Electrodes were designed by calculating the trajectories of electrons in the gun. The maximum peak current of a pulsed electron beam from the gun obtained in the experiments by using a test facility was 30.1 A at a pulse width of 5 ns in FWHM and an anode voltage of 100 kV. This beam current well agreed with that obtained by calculation in the design. The rise time of the beam pulse was 1.6 ns, and was about 60% of that of the previous gun.