Search

Application of CaMoO4 as a scintillation target in cryogenic rare event searches relies on the understanding of scintillation properties of the material at the temperatures at which these detectors operate. We devised and implemented a detection module with a low-temperature photomultiplier from Hamamatsu (model R8520-06) powered by a Cockcroft-Walton generator. The detector module containing the CaMoO4 crystal was placed in a ³He/4He dilution refrigerator and used to measure scintillation characteristics of CaMoO4 in the millikelvin temperature range. At the lowest temperature achieved, the energy resolution of CaMoO4 for 122 keV γ from a 57Co source is found to be 30%, and the fast and slow decay constants are 40.6±0.8 μs and 3410±50 μs, respectively. The temperature variation of the CaMoO4 decay kinetics is discussed in terms of a three-level model of the emission center. [ABSTRACT FROM AUTHOR]

Scintillation properties and radioactive contamination of calcium molybdate scintillating crystals depleted in ^48Ca and enriched in ^100Mo (^40Ca^100MoO4) have been studied to prepare a ^100Mo-based neutrinoless double beta decay experiment. The prospects of a neutrinoless double beta decay experiment using ^40Ca^100 MoO4 crystals are discussed. [ABSTRACT FROM PUBLISHER]

Stochastic aspects of the dynamics of electrons with energies from 150 GeV to several teraelectronvolts in silicon and germanium crystals oriented by the principal crystallographic directions along the beam axis are studied. The computations take into account the influence of emission of hard γ-quanta on the motion of electrons and also their multiple scattering from atoms of the target crystal. The lifetime of the electrons under channeling conditions are computed, and it is shown that this value (in the units of length) exactly coincides with the effective channeling length introduced earlier by Kumakhov [5]. [ABSTRACT FROM AUTHOR]