RObust, long-life photocathodes

Calabazas Creek Research, Inc. and the University of Maryland (UMD) are developing long-life photocathodes than can recover from less than appropriate vacuum conditions. The self-healing photocathodes use advanced materials and configurations developed for thermionic reservoir cathodes. The primary innovation was additional structures to replenish the highly sensitive, cesium sub-monolayer that reduces the work function of the emitter. By monitoring the beam current, users can periodically or continuously match cesium diffusion to the surface at the same rate it evaporates from the emitter.