Performance improvement of keV Neutrons-based PGNAA setups

The performance of keV neutrons based Prompt Gamma Ray Neutron Activation Analysis (PGNAA) setups have been observed to improve by enclosing its neutron source inside the moderator. The keV neutrons were produced via 7Li(p,n) reaction and 3H(p,n) reactions. For the two PGNAA setups, the maximum intensity of the prompt γ-ray yield was observed for a 5 cm long moderator with the neutron source positioned at a distance of 0.5 cm from the moderator-end facing the sample. Due to enclosing the source inside the moderator, the prompt γ-ray yield from the 7Li(p,n) reaction and 3H(p,n) reaction based PGNAA setups have increased by a factor of three as compared to that achieved from these setups with the source outside the moderator. This study provides a theoretical basis for the measurement of performance of 7Li(p,n) reaction and the 3H(p,n) reaction based PGNAA setups.