Gamma background measurements in the Boulby Undergroundl Laboratory

Abstract

To determine background radiation levels that might influence experiments, we measured in situ gammaray emissions at ten locations in the Boulby Underground Laboratory. For gamma radiation in the energy range of 7–2,734 keV, the counts varied from 6.5 to 28 c s-1. For measurements inside the Lab, the arithmetic mean was 24 c s-1. The sedimentary rocks that surrounded the Lab, halite and mudstone, were characterized by very low activity concentrations of uranium (0.8–7.1 Bq kg-1) and thorium (0.6–3.9 Bq kg-1).