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Nuclear Logs
Published in W. Scott Keys, in Environmental Investigations, 2017
Neutron activation in boreholes also is carried out using an electronic neutron generator that emits pulses of neutrons with an energy of 14.2 MeV. A neutron generator accelerates deuterium ions into a tritium target to produce high-energy neutrons. Using a neutron generator, which is pulsed many thousands of times per second, and a synchronously gated detector, short-lived gamma radiation from prompt and capture reactions can be detected.
Radiation Testing Protocols and Mil-Spec Standards
Published in John D. Cressler, H. Alan Mantooth, Extreme Environment Electronics, 2017
A recent request has been made to allow for the use of a neutron generator as a source for DDD testing. A neutron generator can be used to produce monoenergetic neutrons by accelerating deuterium (D) or tritium (T) into a target containing D or T. The D-D reaction produces 2.5 MeV neutrons and the D-T reaction produces 14.1 MeV neutrons.
Benchmarking Neutron Counting System for Passive Measurements and Active Interrogation of Unknown Objects for Fissile and Fissionable Materials Determination
Published in Nuclear Technology, 2023
Fawaz Ali, Ghaouti Bentoumi, Liqian Li, Ronald B. Rogge
Lousteau et al.[6] explored the use of both a 252Cf neutron source and a deuterium-tritium (D-T) neutron generator to irradiate samples to determine their resident 235U enrichment. The interrogation system used in this study was the 252Cf drum shuffler at Oak Ridge National Laboratory.[7] Here, the interrogated sample is placed inside a cavity that in turn is surrounded by 3He detectors embedded inside high-density polyethylene (HDPE). The 252Cf source is shuffled into and out of the cavity using a motorized system. Interrogations using the D-T generator required the placement of the pulsed generator within the cavity. In this study, a relationship was derived between the ratio of the DN count rate from 252Cf and D-T irradiation and the 235U enrichment in the interrogated samples. The use of the 252Cf neutron source and D-T generator allowed for the detection of 235U with mass as low as fractions of a gram. McElroy and Cleveland[8] studied the use of a deuterium-deuterium (D-D) neutron generator as an alternative to americium-lithium neutron sources to detect 235U in interrogated samples. Here, the interrogated sample is placed inside a cavity that in turn is surrounded by a HDPE moderator with 3He detectors placed throughout. The D-D neutrons irradiate the sample by entering the cavity through its lower surface. It was demonstrated that this interrogation system using the D-D generator was able to detect 235U with mass as low as tens of grams.
Model design of a deuterium-deuterium neutron generator moderator and evaluation for delayed gamma-ray nondestructive assay for safeguards verification
Published in Journal of Nuclear Science and Technology, 2021
Fabiana Rossi, Mitsuo Koizumi, Douglas Chase Rodriguez
The Japan Atomic Energy Agency (JAEA) is developing several active nondestructive assay (NDA) techniques. Among these, delayed gamma-ray spectroscopy (DGS) has the potential to determine the ratio of fissile nuclides by measuring the gamma rays emitted from short-lived fission products as they decay [1,2]. Over the past decade, several studies on the feasibility of DGS for the characterization of fissionable material (e.g. 235U and 239Pu) have been performed for different applications, including large waste drums [3]; large nuclear waste packages for actinides [4]; fissionable material contained in matrices like air, wood, water, and lead [5]; and spent nuclear fuel of full assemblies in water environments [6–10]. For this last application, the usage of a deuterium–tritium (D–T) neutron generator was proposed as the neutron source to interrogate the assembly directly in the spent fuel pool, where the water acted as a moderator and reflector.
Utilizing PUNITA experiments to evaluate fundamental delayed gamma-ray spectroscopy interrogation requirements for nuclear safeguards
Published in Journal of Nuclear Science and Technology, 2020
Douglas Chase Rodriguez, Mitsuo Koizumi, Fabiana Rossi, Michio Seya, Tohn Takahashi, Tatjana Bogucarska, Jean-Michel Crochemore, Bent Pedersen, Jun Takamine
Finally, as observed throughout this work, Br and Rb both produce a gamma ray at 2753-keV that should be extremely useful for distinguishing a U contribution from a Pu contribution. However, due to the observed Na decay peak from Al(n,) activation, this presents challenges to the analysis. Since this is caused by the 14-MeV neutrons from the deuterium-tritium neutron generator, using deuterium-deuterium or Cf neutrons that are produced at 2.5 MeV will minimally affect an Al casing. However, the sample containers used for HKED do not contain Al and the final instrument design can address this challenge.