# First Measurement of the Total Neutron Cross Section on Argon Between 100 and 800 MeV

## TL;DR

This paper presents the first experimental measurement of the neutron total cross section on argon within 100-800 MeV, using a liquid argon detector and time-of-flight techniques, providing essential data for neutrino physics and nuclear models.

## Contribution

It introduces a novel measurement of neutron-argon cross sections in the 100-800 MeV range, employing custom algorithms and a liquid argon TPC for the first time.

## Key findings

- Measured average cross section: 0.91 ± 0.10 (stat.) ± 0.09 (sys.) barns
- Compared experimental results with GEANT4 and FLUKA simulations
- Demonstrated feasibility of using liquid argon TPC for neutron cross section measurements

## Abstract

We report the first measurement of the neutron cross section on argon in the energy range of 100-800 MeV. The measurement was obtained with a 4.3-hour exposure of the Mini-CAPTAIN detector to the WNR/LANSCE beam at LANL. The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume. A set of 2,631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms specifically designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector. The energy averaged cross section is $0.91 \pm{} 0.10~\mathrm{(stat.)} \pm{} 0.09~\mathrm{(sys.)}~\mathrm{barns}$. A comparison of the measured cross section is made to the GEANT4 and FLUKA event generator packages.