Neutron spectroscopy using pure LaCl3 crystal and the dependence of pulse shape discrimination on Ce-doped concentrations

Abstract

We report a simple technique for direct neutron spectroscopy using pure LaCl3 crystals. Pure LaCl3 crystals exhibit considerably better pulse shape discrimination (PSD) capabilities with relatively good energy resolution as compared with Ce-doped LaCl3 crystals. Single crystals of pure and Ce-doped LaCl3 were grown using an inhouse-developed Bridgman furnace. PSD capabilities of these crystals were investigated using 241Am and 137Cs sources. Fast neutron detection was tested using a252Cf source and three separate bands corresponding to electron, proton, and alpha were observed. The proton band induced by the 35Cl(n,p)35S reaction can be used for direct neutron spectroscopy because proton energy is proportional to incident neutron energy. Owing to good scintillation performance and excellent PSD capabilities, pure LaCl3 is a promising candidate for space detectors and other applications that necessitate gamma/fast neutron discrimination capability.