  This paper describes the present status of the aging studies in various
photosensitive detectors. New experimental data are presented on aging of
trimethilamine (TMA) and ethilferrocene (EF) photosensitive vapors as well as
on CsI and SbCs photocathodes. A new explanation of the CsI photocathodes aging
process based on solid state physics theory is given. Finally, based on our
studies, a general conclusion was made that thin polymer depositions on the
detector=92s cathode due to the aging can provoke breakdowns through the
Malter-type mechanism (or more precisely- an explosive field emission
mechanism).
