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.
Is the Benussi Effect a Kinetic Depth Effect?
Rapid, successive presentations of an eccentric circle pattern and its mirror-image elicited apparent depth and, as has been previously demonstrated for the Benussi effect, there was an increase in apparent depth with an increase in circle eccentricity. Taken together, these data were interpreted as contravening Wallach, Adams, and Weisz's account of the Benussi effect as an instance of the kinetic depth effect.