Measurement of muon induced neutron background at shallow sites

TL;DR

This paper measures muon-induced neutron backgrounds at shallow sites, crucial for low-background experiments, and discusses mitigation strategies based on measurements from two neutrino experiments.

Contribution

It provides the first detailed measurements of muon-induced neutron rates at shallow sites and evaluates countermeasures for background reduction.

Findings

Muon-induced neutron rates are significant at shallow sites.

Active veto and passive shielding effectively reduce neutron backgrounds.

Results inform design of future low-background experiments.

Abstract

Cosmic muon induced neutrons are a major source of background for low countrate experiments like neutrino oscillation or dark matter searches. Especially at shallow sites these neutrons are the limiting factor for the ultimate sensitivity of the measurement. Measurements of the neutron rate and counter measures including active veto and passive shielding of the detector are discussed for two neutrino oscillation experiments at shallow sites: the KARMEN accelerator based experiment at RAL and the PALO VERDE reactor experiment.