Photomultipliers as High Rate Radiation-Resistant In-Situ Sensors in Future Experiments

Abstract

In the Energy Frontier we suggest developing high rate (100 MHz) finely segmented forward calorimetry preradiators with time resolution <50 ps which will survive the first 1-2 Lint of incident high radiation doses, protecting forward calorimeters 3<y<6; less than 5 degrees to the beam behind them from radiation damage, with high granularity, high rate capability and 30ps time resolution (4D calorimetry) providing lepton and photon ID and measurement. In the Intensity Frontier beam particle selection, such as tagged neutrino and kaon beams, and lepton violation experiments with muons require very high rates. Cosmic Frontiers requiring low power, non-cooled calorimetry or optical detection that can keep track of particles or photons arriving at 100 MHz, and survivable for years in space radiation may also benefit. The basic research is to use compact channelized PMTs with quartz or other radiation resistant windows with metal envelopes as an in-situ sensor, directly coupled to Cerenkov (or radiation-resistant scintillator) tiles, utilizing the dynode signals as a potentially compensating 2nd signal, and with no active electronics. If successful, directions include proposals for high SE yield mesh dynode activator materials such as GaP or B doped diamond films with 25 SEe at 300 eV electron energies, and possibly for compact low cost tile SE sensors with no photocathode, far easier to fabricate than PMTs with all metal final assembly in air, brazed seals; bakeout 900 C; pump out with tipoff - vacuum 100x higher than PMTs. Such sensors have many applications beyond HEP, in research, medicine, industry and defense.