A potential alternative/complement to the traditional thermal neutron based counting in Nuclear Safeguards and Security
Artikel i vetenskaplig tidskrift, 2016

A new concept for thermal neutron based correlation and multiplicity measurements is proposed in this paper. The main idea of the concept consists of using 2.223 MeV gammas (or 1.201 MeV, DE) originating in the (1) H (n,gamma)D-2-reaction instead of using traditional thermal neutron counting. Results of investigations presented in this paper indicate that gammas from thermal neutron capture reactions preserve the information about the correlation characteristics of thermal (fast) neutrons in the same time scale. Therefore, instead of thermal neutron detectors (or as a complement) one may use traditional and inexpensive gamma detectors, such as Nal, BGO, CdZnTe or any other gamma detector. In this work we used D8 x 8 cm(2) Nal scintillator to test the concept. Thus, the new approach helps to address the problem of replacement of He-3-counters and problems related to the specific measurements of spent nuclear fuel directly in the spent fuel pool. It has a particular importance for Nuclear Safeguards and Security. Overall, this work represents the proof of concept study and reports on the experimental and numerical evidence that thermal neutron capture gammas may be used in the context of correlation and multiplicity measurements. Investigations were performed using a (252)-Cf-correlated neutron source and an Am-241-Be-random neutron source. The related idea of the Gamma Differential Die-Away approach is investigated numerically in this paper as well, and will be tested experimentally in future work.

Multiplicity counting

Feynman-alpha

Gamma detection

Gamma Differential Die-Away

Rossi-alpha

Författare

Dina Chernikova

Chalmers, Fysik, Subatomär fysik och plasmafysik

Syed F Naeem

Chalmers, Fysik, Subatomär fysik och plasmafysik

Kåre Axell

Chalmers, Fysik, Subatomär fysik och plasmafysik

Nermin Trnjanin

Chalmers, Fysik, Subatomär fysik och plasmafysik

Anders Nordlund

Chalmers, Fysik, Subatomär fysik och plasmafysik

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

0168-9002 (ISSN)

Vol. 810 164-171

Ämneskategorier

Subatomär fysik

Fusion, plasma och rymdfysik

DOI

10.1016/j.nima.2015.11.146