Journal of Crystal Growth, Vol.393, 13-17, 2014
The LUCIFER project and production issues for crystals needed in rare events physics experiments
The detection of elusive particles and in general the construction of detectors with high sensitivity for applications in the physics of rare events requires the use of new high quality crystals with enhanced characteristics. The production of such materials often depends upon the application of dedicated methods for the entire production process from synthesis of raw materials up to the storage and transport of the finished product ready for use for the construction of the particle detector. Cryogenic bolometers and the more sophisticated scintillating bolometers are among the most promising detectors used in rare event physics, particularly in Neutrinoless Double Beta Decay (O nu DBD) experiments. Operated at extremely low temperatures (approximate to 10mK) such devices need high purity crystals with a very high crystal perfection and low level of intrinsic radioactivity. Moreover, in the case of O nu DBD application, the crystal requires the presence of the nuclide of interest in a sufficient amount i.e. isotope enriched materials are employed. The current work reviews scientific and technological aspects related to the crystal production for rare events physics experiments, particularly for bolometric application. In the case of enriched isotopes used in O nu DBD experiments, the problems related to a maximum production yield are stressed. The discussion is illustrated with results obtained in the activities connected to the procurement of ZnSe crystals for the experiment Low-background Underground Cryogenic Installation For Elusive Rates (LUCIFER). (C) 2013 Elsevier B.V. All rights reserved.
Keywords:Bridgman technique;Semiconducting II-VI materials;Scintillator materials;Cryogenic bolometers