CsI and Cs2Te Photocathodes

Abstract

The development of CsI and Cs2Te solid photocathodes presented the breakthrough in photosensitive gaseous photodetectors we all had been waiting for, and put so much effort in finding. It was actually going back to basic. CsI had for a long time been used in vacuum photomultipliers. It proved to also work well in gas floes, and can even be exposed to air for shorter times. We will describe the development work that led to the current state of the art in solid photocathodes.