Effect of Backing on Neutron Spectra for Low Energy Quasi-Mono-energetic p+$^7$Li Reaction

TL;DR

This study extends a Monte Carlo nucleon transport code to simulate neutron spectra from low-energy p+7Li reactions, comparing results with other models and experiments, and evaluates backing materials for neutron production.

Contribution

The paper develops and applies an extended Monte Carlo code for neutron spectra simulation in p+7Li reactions below 20MeV, incorporating data from ENDF and EXFOR databases.

Findings

Tantalum is effective as backing material below 8 MeV.

Carbon is preferable as backing material at higher energies.

Simulated neutron spectra align well with experimental data.

Abstract

$\underline{\textbf{MO}}$nte-carlo $\underline{\textbf{N}}$ucleon transport $\underline{\textbf{C}}$ode (MONC) for nucleon transport is extended for below 20MeV proton transport using ENDF and EXFOR data base. It is used to simulate p+$^7$Li reaction upto 20MeV proton energies and produced neutron spectra are reported here. The simulated results are compared with calculated values from other available codes like PINO, EPEN, SimLiT and experimental data. The spectra reported here can be used to get the neutron cross-section for the quasi-mono-energetic neutron reaction and will help to subtract the low energy contribution. The neutron spectra also useful as this reaction is used for accelerator based Boron Neutron Capture Therapy. The backing materials are used to fully stop the proton beam hence contribution from the neutrons from backing materials is estimated. It is found that Tantalum is good backing material below $\sim$8 MeV and Carbon is better at higher energies.