Short impulse electron gun for particle accelerator - has pulsed light beam falling on photocathode providing electrons to electron multiplier

摘要

The electron gun providing short pulsed emission includes a pulsed source of optical radiation with an optical appts. for directing the ray on to a photoemissive material, or photocathode. Under the impact of the rays of light the cathode emits electrons. An electron multiplier providing a secondary electron emission comprises a number of microchannels forming a multiplying block. This block has electrically conducting entry and exit faces, the exit face being positively polarised w.r.t. the entry face. Downstream of the block are two electrodes, the first of which is at the same potential as the block exit face and the second being more positive to ensure acceleration and focussing of the electrons.