| Issue |
EPJ Web Conf.
Volume 338, 2025
ANIMMA 2025 – Advancements in Nuclear Instrumentation Measurement Methods and their Applications
|
|
|---|---|---|
| Article Number | 06012 | |
| Number of page(s) | 5 | |
| Section | Nuclear Safeguards, Homeland Security and CBRN | |
| DOI | https://doi.org/10.1051/epjconf/202533806012 | |
| Published online | 06 November 2025 | |
https://doi.org/10.1051/epjconf/202533806012
Fast Neutron Multiplicity Counting for High Mass Plutonium Assay
Institute of Nuclear Physics and Chemistry, CAEP, China
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Published online: 6 November 2025
Abstract
The fast neutron multiplicity counting (FNMC) apparatus was consisted of 36 pieces of liquid scintillator detectors in three rings cylindrical layout, multi-modules of 500M14bit digitizers based on PXIe platform, and mechanical structure. Its center cavity was 35 cm in radius and 50 cm in height for assaying the plutonium item in standard container. The digitizers implemented detector’s signal acquisition, real-time digital data processing and data throughput. Each detector’s light output was calibration with Cs-137 source for nearly equal response. The apparatus detection efficiency for fast neutron calibrated with Cf-252 source was about 3.2%. The fast neutron multiplicity counting analysis was verified with Cf-252 neutron source, then experiments were performed with a serial of different high mass plutonium metals. Two-parameter calibration procedure was used for mass resolving. The mass assay results were consistent with the sample nominal values within maximum bias of 6%. This research achievement demonstrated a promising application for nuclear material assay and verification.
Key words: fast neutron multiplicity counting / FNMC / liquid scintillator / digitizers / plutonium / nuclear material assay
© The Authors, published by EDP Sciences, 2025
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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