Low-Background gamma counting at the Kimballton Underground Research Facility

TL;DR

The paper describes the commissioning and capabilities of a low-background gamma counting facility at KURF, designed for screening materials for radio-purity essential for next-generation physics experiments.

Contribution

It introduces a new underground gamma-counting facility with enhanced background reduction and detailed analysis techniques for material radioactivity screening.

Findings

Achieved over tenfold reduction in background noise underground.

Successfully screened materials for uranium, thorium, potassium, and cosmic-ray isotopes.

Established a reliable method for radio-purity assessment in low-background experiments.

Abstract

The next generation of low-background physics experiments will require the use of materials with unprecedented radio-purity. A gamma-counting facility at the Kimballton Underground Research Facility (KURF) has been commissioned to perform initial screening of materials for radioactivity primarily from nuclides in the 238U and 232Th decay chains, 40K and cosmic-ray induced isotopes. The facility consists of two commercial low-background high purity germanium (HPGe) detectors. A continuum background reduction better than a factor of 10 was achieved by going underground. This paper describes the facility, detector systems, analysis techniques and selected assay results.