Development of the active neutron-based interrogation system with D-D neutron source for the detection of special nuclear materials

Abstract

The detection of hidden special nuclear materials (SNMs) is important issue for nuclear security. For this purpose, we have been developing an active neutron-based interrogation system combined with a D-D fusion neutron source, which is a compact discharge-type fusion neutron source called IEC (Inertial-Electrostatic Confinement Fusion) device and provides pulsed neutrons of 2.45MeV. The neutron noise analysis method and the detection of high energy fission neutron spectrum are employed for detection of SNMs.

Non-destructive inspection system for special nuclear material using inertial electrostatic confinement fusion neutrons and Laser Compton Scattering Gamma-rays

“…It is seen that the Y-value was larger than zero when the enriched uranium plates present. In contrast, such a clear indication of enriched uranium presence was not seen by the conventional Feynman-alpha method [5]. This difference would result from an effect of initial neutron source statistics.…”

“…The count rate of the detector caused by neutron elastic scattering reactions by hydrogen nuclide in the detector was then evaluated. It was found the count rate with the neutrons above 2.45 MeV was ~60 cps, which is expected to be higher than a count rate of background signals induced by either gamma-rays or pileup signals of less energetic neutrons [5].…”

“…Four 3 He counters were placed nearby the enriched uranium plates. Further details are given in ref [5].…”

“…The two techniques of neutron-in neutron-out interrogation of SNMs are being investigated in our group [5]. A neutron generator based on inertial electrostatic confinement (IEC) [6,7] of fusion plasmas with an averaged D-D neutron flux of 10 8 neutrons/sec has been developed and is to be used for those techniques.…”

Active Interrogation of Depleted Uranium Using a Single Pulse, High-Intensity Photon and Mixed Photon-Neutron Source

“…The majority of sources used for active interrogation employ neutron or photon radiation. Many methods for generating the required radiation have been proposed: neutrons from deuterium-deuterium (DD) [3] or deuterium-tritium (DT) fusion generators [4] or other ion-based reactions [5], mono-energetic gamma-rays from ion-based reactions [6], and bremsstrahlung x-rays from electron accelerators [7]. These sources are most commonly operated in a pulsed mode, using linear accelerators (LINAC) or pulsed neutron generators with beam currents in the A range, pulse widths of order s, and frequencies up to several thousand Hz.…”