A single-shot nanosecond neutron pulsed technique for the detection of fissile materials

Abstract

A novel technique with the potential of detecting hidden fissile materials is presented utilizing the interaction of a single powerful and nanosecond wide neutron pulse with matter. The experimental system is based on a Dense Plasma Focus (DPF) device as a neutron source generating pulses of almost mono-energetic 2.45 MeV and/or 14.0 MeV neutrons, a few nanoseconds in width. Fissile materials, consisting of heavy nuclei, are detected utilizing two signatures: firstly by measuring those secondary fission neutrons which are faster than the elastically scattered 2.45 MeV neutrons of the D-D reaction in the DPF; secondly by measuring the pulses of the slower secondary fission neutrons following the pulse of the fast 14 MeV neutrons from the D-T reaction. In both cases it is important to compare the measured spectrum of the fission neutrons induced by the 2.45 MeV or 14 MeV neutron pulse of the DPF with theoretical spectra obtained by mathematical simulation. Therefore, results of numerical modelling of the proposed system, using the MCNP5 and the FLUKA codes are presented and compared with experimental data.

Taxonomy of Big Nuclear Fusion Chambers Provided by Means of Nanosecond Neutron Pulses

“…Moreover, it appears that these subsequent pulses contain higher energy X-ray photons compared with the first pulse. We observe already in our earlier experiments such a phenomenon (see e.g., [23,24] Table 8. Data on the angular tracking of energy distribution of neutrons at the PF-6 device in the hall with a simulator of a tokamak section (the PF-1000U discharge chamber) with angles and distances in a horizontal plane with Z-axis of both devices and PMT + Ss.…”

Estimation of the performance of multiple active neutron interrogation signatures for detecting shielded HEU

“…[11] Tartaglione et al, and later Gribkov et al and others have also illustrated the potential value time-of-flight analyses can have when interpreting active interrogation signatures, including its use with repetitively-pulsed neutron sources. [11][12][13] Shaw et al have presented data showing how x-ray radiography may be used to reduce the scanning times needed for cargo screening when using neutron interrogation measurements focused on differential die-away analysis. [14] Others have discussed similar approaches for combining prompt and delayed fission signatures for SNM detection.…”