The /spl mu/-Witness Detector: A Ruggedized, Portable, Flux Meter for Cosmogenic Activation Monitoring

This paper presents the design and construction of a portable muon flux monitor based on coincidence counts between two scintillator panels to be used as an indicator for cosmogenic exposure history of detector materials. The Muon Witness detector (μ -Witness) has been designed to count for long periods of time (up to 40 days) using battery power and is mounted in a ruggedized case to enable measurements in transport container environments. The purpose of this apparatus is to accurately account for the cosmic-ray exposure of enriched germanium batches that will become the active detector crystals in neutrinoless double-beta decay experiments. The success of such experiments depends on the ability to mitigate and quantify backgrounds, including accurately estimating the radioactive isotopes induced by cosmogenic activation while the detectors are on the Earth´s surface, prior to going underground.