Study on the characteristics of lead-glass γ-spectrometer radiators irradiated by high energy particles

For the purpose of enchancing the operation reliability of precision hodoscopic spectrometers changes in the transparancy of F8-00 type lead-glass radiators being close to F2 european standard, TF1-000 close to SF-2 and F101 (F8 class radiation resistant glass) have been studied. The mesurements are performed on proton beam at 70 GeV with intensity of 1010-1111 protons in a cycle. F8-type glass radiators irradiated by π-meson beam at 30 GeV have been also investigated. Universal dependences describing deterioration and restoration of radiator transparancy upon irradiation and change in spectrometer counters characteristics. It is shown that the radiation resistance of the TF-1-type glass is 1.4 times less than of F8-type which in its turn is 60 times less than of F101-type glass. To avoid losses in energy spectrometer resolution, radiators which are suject to the most intensive irradiation (usually in the central part of the detector, in the beam zone), are to be manufactured from radiation-resistant lead glass as well as to liberate the detector of the substance on the beam path. Such measures have been realized, for example, in GAMS-2000 and GAMS-4000 spectrometers which permits to expose them for a long period in the beams with intensity up to 2107 pions per cycle