RESISTANCE OF LEAD TUNGSTATE AND CERIUM FLUORIDE TO LOW RATE GAMMA IRRADIATION OR FAST NEUTRONS EXPOSURE
We present here the results of recent low dose rate gamma irradiation of lead tungstate and cerium fluoride long crystals, and, for lead tungstate only, fast neutron exposure. For the low rate tests, recovery processes are taking place during irradiation and, compared to the usual high rate tests, only a very low damage is noticed, if any. No saturation effect is observed in these previously irradiated samples. For the neutron tests, a very small variation with fluence is not excluded, after a fast saturation at low fluence. The samples tested here are very resistant.
Progress in PbWO4 scintillating crystal
The latest results in improvement of scintillator properties with Nb doping of PbWO4 crystal are presented. The effects on the basic parameters of the crystal, such as radiation hardness, decay time and light yield, are evaluated.
Beam test of a calorimeter prototype of PWO crystals at energies between 0.5 and 2.5 GeV
The results of a beam test are presented concerning the energy resolution of a calorimeter hodoscope prototype of PWO (PbWO4) crystals, measured by electron beams having energies between 0.5 and 2.5 GeV. The hodoscope consists of a 3 × 3 matrix of modules of PWOs having dimensions of 20 mm × 20 mm in cross section and 200 mm in length. The energy dependence of the energy resolution is obtained to be (σ/EGeV))2=((0.0310±0.0011)/E(Gev))2+(0.0079±0.0025)2, fitted by a quadratic form.