Fast neutron spectroscopy from 1 MeV up to 15 MeV with Mimac-FastN, a mobile and directional fast neutron spectrometer

TL;DR

The paper introduces Mimac-FastN, a portable, directional neutron spectrometer capable of measuring fast neutrons from 1 MeV to 15 MeV, aiding in dark matter background discrimination.

Contribution

It presents the development and characterization of Mimac-FastN, a novel portable neutron spectrometer with a wide energy range and directional detection capabilities.

Findings

Effective neutron energy measurement from 1 to 15 MeV.

Demonstrated directional detection at the GENESIS facility.

Potential application in dark matter search backgrounds.

Abstract

In the frame of direct dark matter search, the fast neutrons producing elastic collisions are the ultimate background. The MIMAC (MIcro-tpc MAtrix Chambers) project has developed a directional detector providing the directional signature to discriminate them based on 3D nuclear tracks reconstruction. The MIMAC team of the LPSC has adapted one MIMAC chamber as a portable fast neutron spectrometer, the Mimac-FastN detector, having a very large neutron energy range (10 keV - 600 MeV) with different gas mixtures and pressures. The present paper shows its main features and functionality and demonstrates its potential in the energy range from 1 MeV to 15 MeV at the GENESIS neutron source facility of LPSC.