Background in Liquid Scintillation Counting Systems

This paper gives estimates, for a particular radiocarbon dating system, of two possible sources of residual background occurring in coincident liquid scintillation arrangements - the natural radioactivity of the phototubes and optical feedback between them. The formr was found to contribute about 1.8 c.p.m. or 13% of the background, but there was no evidence of any significant contribution from the latter.