Neutron moderator structure improvement of a PGNAA online analysis system based on DT neutron generator

The neutron moderator structure of a prompt gamma-ray neutron activation analysis (PGNAA) system based on a deuterium-tritium (DT) neutron generator was re-optimized. In this study, a 1 cm lead combined with a 2 cm high-density polyethylene (HDPE) was set as a new moderator. The thermal neutron flux, fast neutron flux of more than 6 MeV and total neutron flux in the samples increased by 22%, 41% and 41%, respectively. The signal-to-interference ratio (SIR) increased from 15 to 19%. The measurement results with samples containing different element contents indicated that the detection sensitivity of the analyzer with the new moderator structure was significantly improved.

Automated summary

The neutron moderator structure of a prompt gamma-ray neutron activation analysis (PGNAA) system based on a deuterium-tritium (DT) neutron generator was re-optimized. A combination of 1 cm lead and 2 cm high-density polyethylene (HDPE) was set as a new moderator. The thermal neutron flux, fast neutron flux of more than 6 MeV, and total neutron flux in the samples increased by 22%, 41%, and 41%, respectively. The signal-to-interference ratio (SIR) increased from 15 to 19%. The analyzer with the new moderator structure showed significantly improved detection sensitivity for samples with different element contents.