Characteristics of double-pulsed intense electron beams generated by velvet cathode

Velvet as a cathode has the ability to emit intense multi-pulsed beams. The characteristics of the double-pulsed relativistic electron beams generated by velvet cathode were studied. The integral emittance and brightness of the double-pulsed beams were presented. The time-resolved envelope radii of the beams were measured. The double-pulsed beams integral brightness reached up to about 108 A·(m·rad)-2 in the experiment. It was the difference of the influence of the cathode plasma generated in the process of emitting beams on the vacuum diode and the recovery velocity of the cathode plasma that resulted in the different envelope radii of the two beams.