Neutron scintillating glasses: Part 1. Activation by external charged particles and thermal neutrons
A synopsis of the development of amorphous glass scintillators for thermal neutron detection via the 6Li(n, α) is given. The complete, available, range of commercial scintillators have been tested under neutron, alpha and beta excitation. For all the radiation sources, the variation in pulse height with glass composition follows a common pattern, related in the paper to the degree of divergence from the composition of a related polycrystalline X-ray phosphor. For external particle excitation, the count rate at the peak of the pulse height distribution relates directly to the pulse height patterns. For neutron excitation, the count rate follows the 6Li concentration, but not exactly. Calculations on ionisation densities, atomic spacings and glass species densities are reported and correlated with the experimental results. A detailed analysis of pulse height spectrum at the peak of the 6Li(n, α) indicates the superior performance of the low lithium content, enriched 6Li glasses, in respect of pulse height statistics and energy discrimination. Further experiments to be reported soon are described in respect of their contribution to the understanding of energy transfer processes in these scintillators. Attention is drawn to the observed deviations between measured lithium content and content based on compositional data. Non-uniform lithium distribution of 10% has been observed and is reported.