Aging in gaseous photodetectors
  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). 
T. Francke (Royal Institute of Technology), V. Peskov (Royal Institute   of Technology)