Contamination of α-particle detectors by desorption of 222Rn progeny from metal surfaces

Abstract

Radon-222 progeny collected on filter substrates and other large surfaces desorb from these surfaces by α- and β-recoil processes, and other mechanisms. Because of this, an α-particle detector such as silicon-barrier detector, used routinely in the assessment of 222Rn progeny, can become contaminated to the extent that it precludes its further use for accurate low-activity counting. This paper presents data regarding surface contamination of α-particle detectors after long counting periods of 222Rn progeny samples.