The scintillators currently providing the best energy resolution lower than 2.6% at 662 keV and sizes larger than 1 in. dia. 1 in. height are LaBr3(Ce) and SrI2(Eu). Despite energy resolution and decay time performance of LaBr3(Ce), the intrinsic radioactivity, due to naturally occurring 138La isotope in the matrix is a limitation for low count rate applications such as radioisotope identification of weak sources. Cesium Hafnium Chloride (CHC) is a high effective atomic number (Zeff=58) moderate density (3.86 g/cm3) scintillator for gamma spectroscopy, offering a cubic crystal structure, no intrinsic radioactivity, and highly proportional light yield, without intentional doping. CHC boasts a cubic crystal structure that is isostructural to K2HfCl6 and analogous to calcium fluoride with cesium ions in the fluorine ion position and the [HfCl6]2- octahedral replacing calcium ions. The scintillation of CHC is centered at 400 nm, with a principal decay time of 4.37 s, a light yield of up to 54,000 photons/MeV and energy resolution of 3.3% at 662 keV and we report on the effects of doping on the scintillation properties of CHC.

Date Published: 2 November 2016
PDF: 1 pages
Proc. SPIE 9968, Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XVIII, 996804 (2 November 2016); doi: 10.1117/12.2238318

Published in SPIE Proceedings Vol. 9968:
Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XVIII
Ralph B. James; Michael Fiederle; Arnold Burger; Larry Franks, Editor(s)