Published July 2023 | Version v1
Journal article Metadata-only

Relationship between neutron moderator and time-dependent background for neutron time-of-flight measurement

Creators

  • 1. Japan Atomic Energy Agency, Integrated Support Center for Nuclear Nonproliferation and Nuclear Security, Tokai, Ibaraki (Japan)
  • 2. Kyoto University, Institute for Integrated Radiation and Nuclear Science, Kumatori, Osaka (Japan)
  • 3. Kindai University, Atomic Energy Research Institute, Higashiosaka, Osaka (Japan)

Description

In short-distance time-of-flight measurements, the background events increase exponentially with decreasing distance. Furthermore, the large number of background events increases the uncertainty of the measured data. The moderated neutron beam includes the time-dependent background originating from the neutron moderator, such as the 2.2 MeV gamma rays emitted by 1H (n,γ) reaction in the moderator. In this study, to develop a compact neutron resonance transmission analysis system with high accuracy, we studied the relationship between the moderator and time-dependent background based on gamma rays. Monte Carlo simulations were conducted based on PHITS and JENDL-4.0 to investigate the time distributions of neutrons and gamma rays emitted from the moderator. Ratios of the gamma-ray intensity to neutron intensity (Sγ/Sn ratio) were calculated for various moderators and flight distances. The moderator designs were discussed based on the obtained results for maintaining a low Sγ/Sn ratio. (author)

Availability note (English)

Available from DOI: https://doi.org/10.1080/00223131.2023.2224330

Additional details

Identifiers

DOI
10.1080/00223131.2023.2224330;

Publishing Information

Journal Title
Journal of Nuclear Science and Technology (Tokyo) (Online)
Journal Volume
61
Journal Issue
1
Journal Page Range
p. 23-30
ISSN
1881-1248

INIS

Country of Publication
Japan
Country of Input or Organization
Japan
INIS RN
56002753
Subject category
S46: INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; S73: NUCLEAR PHYSICS AND RADIATION PHYSICS;
Descriptors DEI
ACCURACY; BACKGROUND RADIATION; COMPUTERIZED SIMULATION; DISTANCE; DISTRIBUTION; GAMMA RADIATION; MODERATORS; MONTE CARLO METHOD; NEUTRON BEAMS; NEUTRON DETECTION; NEUTRON DETECTORS; NEUTRON REACTIONS; NUCLEAR DATA COLLECTIONS; TIME DEPENDENCE; TIME MEASUREMENT; TIME-OF-FLIGHT METHOD
Descriptors DEC
BARYON REACTIONS; BEAMS; CALCULATION METHODS; DETECTION; ELECTROMAGNETIC RADIATION; HADRON REACTIONS; IONIZING RADIATIONS; MEASURING INSTRUMENTS; NUCLEAR REACTIONS; NUCLEON BEAMS; NUCLEON REACTIONS; PARTICLE BEAMS; RADIATION DETECTION; RADIATION DETECTORS; RADIATIONS; SIMULATION

Optional Information

Notes
21 refs., 9 figs., 4 tabs.