NEW HIGH-PERFORMANCE SCINTILLATORS BASED ON RE-ACTIVATED INSULATOR MATERIALS

In this paper we address the problem of the most-to-ion energy transfe r in some RE-activated wide band gap materials excited by ionizing rad iation. We argue that, despite tile expected self-localization of hole s, the dominant mechanism in efficient materials involves sequential t rapping of both charge carriers (holes and electrons) by an activating RE-ion followed by a radiative recombination via tile ion producing s cintillation light. Selected experimental results are presented to ill ustrate how various energy transfer processes manifest themselves in t ile spectroscopy of scintillator materials. Experimental results combi ned with simple considerations are used to identify these RE-ions whic h are likely to act as hole or electron traps in tri- and difluorides, thus initiating the recombination sequence leading to efficient scint illation.