LaCl3:Ce coincidence signatures to calibrate gamma-ray detectors

Calibrating the gamma-ray detection efficiency of radiation detectors in a field environment is difficult under most circumstances. To counter this problem we have developed a technique that uses a Cerium doped Lanthanum-Tri-Chloride (LaCl3:Ce) scintillation detector to provide gated gammas (Guillot-Noël et al. (1999) [1] and van Loef et al. (2001) [2]). Exploiting the inherent radioactivity of the LaCl3:Ce due to the long-lived radioactive isotope 138La (t1/2=1.06×1011 yr) allows the use of the 788 and 1436 keV gammas as a measure of efficiency. In this paper, we explore the effectiveness of using the beta-gamma coincidences radiation LaCl3:Ce detector to calibrate the energy and efficiency of a number of gamma-ray detectors.