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.
Measurements of lead tungstate crystals behaviour under irradiation for the CMS electromagnetic calorimeter at the LHC
Lead tungstate crystals will be used as calorimetric medium in high energy physics at CERN, in a particularly hostile radiation environment. Methods of testing their behaviour under irradiation are discussed here and are illustrated by some R&D results.
Luminescence of Lead Molybdate and Lead Tungstate. I. Experimental
Optical properties of single crystals of lead molybdate and lead tungstate (scheelite structure) have been investigated in order to identify the nature of the luminescent centres. Absorption, emission, and excitation spectra at different temperatures (1.5 to 300 K) and photoconductivity and quantum efficiency measurements at 77 K are reported. The greenyellow emission of both compounds is probably due to a centre being very much alike in PbMoO4 and PbWO4. The blue emission of PbWO4 is ascribed to the tungstate group as in the alkaline-earth tungstates. 
 
 
 
Die optischen Eigenschaften von Bleimolybdat- und Bleiwolframateinkristallen (Scheelitstruktur) wurden zur Ermittlung der Art der emittierenden Zentren untersucht. Absorptions-, Emissions- und Anregungsspektren wurden bei verschiedenen Temperaturen (1,5 bis 300 K) und die Photoleitfahigkeit und Quantenausbeute bei 77 K gemessen. Die gelbgrune Emission von PbMoO4 und PbWO4 mus wahrscheinlich Zentren zugeschrieben werden, die in beiden Verbindungen einander sehr ahnlich sind. Die blaue Emission wird auf die Wolframatgruppe wie in den Erdalkaliwolframaten zuruckgefuhrt.