Proton induced activation of LaBr3:Ce and LaCl3:Ce

In the framework of an assessment of lanthanum halide scintillators, such as LaBr3:Ce and LaCl3:Ce on their suitability for space based gamma-ray spectroscopy, proton induced activation of the materials has been studied. One inch scintillators were subjected to proton irradiations in the range of 60–184 MeV, where after the activation was measured. The activation was analyzed by identifying the decaying isotopes by means of gamma-ray spectroscopy and lifetime measurements using both a germanium detector and the activated scintillator itself. It was found that the dominant source of activation in the scintillators originates from the lighter elements in the materials: bromide and chloride, respectively. The activation of LaBr3:Ce manifest itself through gamma-decay, which partly leaves the volume. Activation of LaCl3:Ce originates mainly from beta decay, which is confined to the volume itself.