Kinetics of luminescence intensity decrease upon PbWO_4 crystal excitation by H~+ ion beam

摘要

The luminescence dampenness of PbWO_4 crystals upon their excitation by H~+ ion beam (E_0 = 0.9 MeV) during prolonged time intervals was studied. An exponential law for the luminescence yield reduction at a density of the beam proton irradiation of j ≈ 6·10~(12) ion/cm~2 was registered, with the yield falling to a final value of J_∞ ≈ 1/3·J_0. Similar kind modification of the luminescence yield suggests that some channels of the radiative relaxation process for intermediate excited states in the PbWO_4 bandgap could be blocked in part by local high energy excitation produced by energetic protons in the unit cells of lead tungstate.