Radiation-hard photodetectors based on fine-mesh phototubes for calorimetry in very forward rapidity

This paper presents results of a study of a very radiation-hard photodetector—a high-gain fine-mesh PMT with a highly radiation-hard faceplate made of UV-transparent glass. Radiation resistance of these PMTs to gamma rays and neutrons was investigated at the PNPI gamma facility and nuclear reactor with neutron fluences of up to 10 16 n / cm 2 at 0.95 MeV and gamma ray doses of 20–50 kGy with excellent results. Measurements of insensitivity to magnetic fields and immunity of the PMT against helium at levels expected in the LHC environment are also presented.