Speaker
Description
This work presents initial steps toward assessing the feasibility of using high-pressure helium-4 (He-4) scintillation detectors in an active-interrogation system utilising the Threshold Energy Neutron Analysis (TENA) technique for the detection of special nuclear materials (SNMs). The proposed setup consists of a deuterium–deuterium (DD) based Inertial Electrostatic Confinement (IECF) fusor as the interrogation source, arrays of Arktis S670 He-4 detectors, and the detection of neutrons with energies higher than the probing source (~2.45 MeV), which serves as a robust indicator of the presence of SNM. These detectors offer strong potential for this detection scheme due to their exceptional gamma rejection (~10⁻⁷), fast timing resolution (tens of nanoseconds), and their ability to provide information on neutron energy spectra through recoil-energy deposition.
Here, we evaluate Geant4 simulations that were used to determine the intrinsic neutron-detection efficiency of a high-pressure He-4 detector over the energy range of 0.5–20 MeV, with results benchmarked against published experimental data. Simulated energy-deposition spectra are used to establish an effective detection threshold for the 2.45 MeV DD neutron source. Using this threshold, the performance of the He-4 detector is compared with that of Centrifugally Tensioned Metastable Fluid Detectors (CTMFDs) for the detection of SNM under representative experimental conditions.
