Data for A New Neutron Multiplicity Device Based on Portable D-D Neutron Generator

To address the international community’s needs for the safeguarding and monitoring of enriched uranium materials and to prevent the illicit theft, destruction, and transfer of such materials, it is crucial to explore non-destructive analytical techniques for measuring uranium content in enriched uranium materials. Currently, the Am-Li source is commonly used as an excitation source in active uranium measurement methods. However, as the acquisition of Am-Li becomes increasingly challenging, controllable accelerator-based neutron sources have emerged as preferred alternatives due to their superior energy monochromaticity, controlled yield, and on-demand operational capabilities. This study is based on the neutron multiplicity device using a portable D-D neutron generator instead of an Am Li source. It focuses on the optimization of the device structure and the performance simulation. Monte Carlo simulation software was used to evaluate critical measurement parameters, including the distance between the neutron generator and the two-layer He-3 detection array, the length of the He-3 tubes, and the materials and thicknesses of the reflective layers. Following the design phase, simulations were conducted to determine the detection efficiency and neutron decay time of the new device. Additionally, the device’s performance was evaluated through simulated measurements and quantification of uranium materials with different U-235 abundances and masses. The results indicate that for samples with U-235 enrichment exceeding 50%, the relative deviation of the measurements is less than 10%, and deviations for other enrichment levels are less than 100 g. Finally, the sources of quantification error in the device were examined, and corrections were made to the calculation of the neutron leakage multiplication using the fission neutron detection efficiency. This research lays the groundwork for the study and experimental validation of the neutron multiplicity device based on D-D neutron generators.