The simulation on neutron background reduction for InDEx at JUSL

TL;DR

This paper presents a simulation study on neutron background reduction for the InDEx dark matter experiment in India, demonstrating that HDPE shielding can significantly lower detector event rates.

Contribution

It introduces a detailed FLUKA/FLAIR simulation of InDEx, validating results against experimental data, and proposes an effective shielding design for background reduction.

Findings

Shielding reduces detector event rates by two orders of magnitude.

Simulation results align well with experimental data for validation.

HDPE shielding is effective for future dark matter experiments.

Abstract

Dark matter experiments are rare event search experiments that require zero background environment over very long exposures. To achieve this condition, a detailed simulation of detector geometry and experimental setup is required before the experiment is executed. Simulation plays a significant role in detector design and also provides a cost-effective and risk-free approach for predicting outcomes before real world experimentation. The present simulation work is focused on neutron background reduction for a dark matter direct detection experiment in India, the Indian Dark matter search Experiment (InDEx). The FLUKA and FLAIR simulation tools have been used throughout the simulation process. The experimental and simulation results available in the literature are being reproduced using FLUKA for validation purposes. The calibration and InDEx experiment are simulated, and the results are compared against the experimental results. For neutron background reduction in future experiments, the use of high density polyethylene (HDPE) is suggested and a shielding design using HDPE is presented. The results show that shielding reduces detector event rates by two orders of magnitude compared to the prior InDEx experiment without shielding.