Stoichiometric cerium compounds as scintillators, II. CeP5 O14

For pt.I see NSSMI Conf. Record, Nov., 1991, NM, USA. Results showing the relative importance of several processes which are responsible for the efficiency and speed of a scintillator are presented. Arguments for concentrated materials are presented and illustrated in the case of Ce-pentaphosphate, (CeP₅O₁₄ ). The low density of this material does not make it a viable scintillator, but its remarkable simplicity and relatively easy technology make it perfect to study basic physical mechanisms of scintillation in concentrated materials. Based on studies of a series of Ce_xLa_1-xP₅O₁₄ crystals, the authors formulate general conclusions relating to the relative importance of the process starting with direct ionization of the emitting centers (Ce³⁺) versus long range gathering of electron-hole pairs. These conclusions provide guidance for optimizing the speed and efficiency of future concentrated scintillators. Some peculiarities of the Ce-pentaphosphate luminescence are reported and interpreted