An aerogel Cherenkov detector for multi-GeV photon detection with low sensitivity to neutrons

TL;DR

This paper introduces a lead-aerogel sandwich Cherenkov detector capable of detecting multi-GeV photons with over 99.5% efficiency while maintaining low sensitivity to neutrons, suitable for high-flux environments.

Contribution

The paper presents a novel detector design that achieves high photon detection efficiency and neutron blindness, validated through simulations and experimental measurements.

Findings

Photon detection efficiency >99.5% for >1 GeV photons

Neutron sensitivity less than 1% for 2 GeV/$c$ neutrons

Experimental results agree with simulations within 8.2% uncertainty

Abstract

We describe a novel photon detector which operates under an intense flux of neutrons. It is composed of lead-aerogel sandwich counter modules. Its salient features are high photon detection efficiency and blindness to neutrons. As a result of Monte Carlo (MC) simulations, the efficiency for photons with the energy larger than 1 GeV is expected to be higher than 99.5% and that for 2 GeV/$c$ neutrons less than 1%. The performance on the photon detection under such a large flux of neutrons was measured for a part of the detector. It was confirmed that the efficiency to photons with the energy $>$1 GeV was consistent with the MC expectation within 8.2% uncertainty.