LaBr 3 scintillator response to admixed neutron and γ-ray fluxes

The γ-ray spectroscopy is a promising method for diagnosing fast ions and confined α particles in a fusion plasma device. This application requires γ-ray detectors with high energy resolution (say a few percent for γ-ray energies in the range 1–5MeV), high efficiency and high count rate capability, ideally up to a few MHz. Furthermore, the detector will have to withstand the high 14MeV and 2.45MeV neutron fluxes produced by the main fusion reactions between deuterium and tritium. Experimental results demonstrate that the requirements on energy resolution, efficiency and count rate can be met with a LaBr3(Ce) scintillator detector equipped with fast digital data acquisition. The measured response of the detector to 2.45MeV neutrons is presented in this paper and discussed in terms of the interaction mechanism between neutrons and detector.