Application of PbWO4 crystal scintillators in experiment to search for 2 beta decay of Cd-116

Lead tungstate (PbWO4) crystal scintillators are discussed as an active shield and light guides in Cd-116 double-beta decay experiment with Cadmium tungstate (CdWO4) scintillators. Scintillation properties and radioactive contamination of PbWO4 scintillators were investigated. Energy resolution of CdWO4 detector, coupled to PbWO4 light guide, was tested. Efficiency of PbWO4-based active shield to suppress background from the internal contamination of PbWO4 crystals, as well as possible contribution from radioactivity of copper shield and phototubes were calculated. Using of lead tungstate crystal scintillators as high-efficiency 4 pi active shield could allow to build sensitive 2 beta experiment (T-1/2(0 nu 2 beta) similar to 10(26) yr) to search for 0 nu 2 beta decay of Cd-116 with (CdWO4)-Cd-116 crystal scintillators. (c) 2005 Elsevier B.V. All rights reserved.