Performances of a CeF3 crystal scintillator and its application to the search for rare processes

The performances of a CeF3 crystal scintillator with a mass of 49.3 g have been investigated. In particular, the alpha/beta light ratio and the possibility of a pulse-shape discrimination between alpha particles and gamma quanta have been studied. The radioactive contamination of the crystal has been investigated. The application of the obtained results in the search for rare processes such as the two neutrino double electron capture in Ce-136 and Ce-138 and the alpha activity in Ce-142 has been investigated. As a result, new T-1/2 limits for these processes have been deter-mined (90% C.L.): T-1/2(2v2) (K)(Ce-136)greater than or equal to 2 7 x 10(16) yr, T-1/2(2v2) (K)(Ce-138)greater than or equal to 3.7 x 10(16) yr and T-1/2(alpha) (Ce-142)greater than or equal to 2.9 x 10(18) yr. (C) 2003 Elsevier Science B.V. All rights reserved.