Method for measuring prompt gamma-rays generated by D-T neutrons bombarding a depleted uranium spherical shell

TL;DR

This paper presents a new method combining experimental measurements and Monte Carlo simulations to accurately characterize prompt gamma-ray spectra from depleted uranium shells bombarded by 14 MeV D-T neutrons, including background subtraction and spectrum unfolding techniques.

Contribution

It introduces the DC-TOF method for prompt gamma-ray measurement and demonstrates its effectiveness through experimental data and simulation comparison.

Findings

Optimal DU shell thickness is 3-5 cm for maximum gamma flux.

Measured gamma spectra agree well with MC simulations, with minor discrepancies.

The method effectively removes background and response matrix effects in spectrum analysis.

Abstract

The prompt gamma-ray spectrum from depleted uranium (DU) spherical shells induced by 14 MeV D-T neutrons is measured. Monte Carlo (MC) simulation gives the largest prompt gamma flux with the optimal thickness of the DU spherical shells 3-5 cm and the optimal frequency of neutron pulse 1 MHz. The method of time of flight and pulse shape coincidence with energy (DC-TOF) is proposed, and the subtraction of the background gamma-rays discussed in detail. The electron recoil spectrum and time spectrum of the prompt gamma-rays are obtained based on a 2"*2" BC501A liquid scintillator detector. The energy spectrum and time spectrum of prompt gamma-rays are obtained based on an iterative unfolding method that can remove the influence of {\gamma}-rays response matrix and pulsed neutron shape. The measured time spectrum and the calculated results are roughly consistent with each other. Experimental prompt gamma-ray spectrum in the 0.4-3 MeV energy region agree well with MC simulation based on the ENDF/BVI.5 library, and the discrepancies for the integral quantities of gamma-rays of energy 0.4-1 MeV and 1-3 MeV are 9.2% and 1.1%, respectively.