Simulation of the response functions of Extended Range Neutron Multisphere Spectrometer using FLUKA program

TL;DR

This study uses FLUKA to simulate neutron response functions of an extended range neutron multisphere spectrometer, validating the method and designing detectors for accurate neutron measurement in high-energy environments.

Contribution

It demonstrates the feasibility of using FLUKA for simulating response functions of neutron spectrometers and designs an optimized detector array based on simulation results.

Findings

Neutron radiation dominates the radiation field in the CSNS hall.

FLUKA simulations agree with MCNP calculations, validating the approach.

Eleven detectors are selected for the ERNMS based on simulation outcomes.

Abstract

In this paper, the distribution of radiation field in the CSNS spectrometer hall was simulated by FLUKA program. The results showed that the radiation field of high energy proton accelerator is dominated by neutron radiation, and the range of neutron energy is quite widely, including about eleven orders of magnitude. Nextly, work of simulation and calculation of the response functions of four Bonner spheres with simplified model is done by FLUKA and MCNP codes respectively, and the acceptable difference proved the feasibility of FLUKA program in this application and the correctness of the relevant calculation method. Through adopting the actual model, we simulate and calculate the energy response functions of Bonner sphere detectors with polyethylene layers of different diameters, including the detectors with lead layers by using FLUKA code. According to the simulation results, we select eleven detectors as the basic structure of ERNMS.