New Thermal Neutron Scintillators: and

The thermal neutron detection properties of and single crystals are presented. The compounds show high scintillation photon yields of 70 000 and 88 200 photons emitted per absorbed thermal neutron, respectively. Events caused by primary electrons with energy below 2.9 and 3.4 MeV, respectively, can be separated from neutron-induced events by pulse-height discrimination. For , due to the presence of a 4-ns fast core-va- lence luminescence, thermal neutrons and gamma rays can also be discrim- inated by means of the shape of the scintillation pulse. The main part of the scintillation pulse in is relatively slow, how- ever, has a relatively intense component with decay time.