Thermal flux perturbation of lithium-glass scintillator

Experimental and calculational investigations were made on thermal flux perturbation of 6Li-enriched lithium-glass scintillators placed in a graphite pile. The (n, α) reaction rates were measured for the various glass scintillators for four different thicknesses and three different 6Li contents. It was shown that the decrease of the reaction rate due to the flux perturbation is 66% for 1 mm thick, 6.3% 6Li content glass, and 3% for 0.1 mm thick, 1.0% 6Li content glass. A calculation of the flux perturbation was performed by the modified Skyrme theory and close agreement with the measurement was obtained. The self-shielding effect was also calculated by a Monte Carlo method, and its dependence on energy was discussed. (orig.)