CXLIV. K-capture in the decay of chlorine 36

A search for the existence of K-capture in ^(36)C1 has been made using a proportional tube spectrometer with labelled methyl chloride as a gaseous source. A peak which was observed in the beta spectrum corresponded to the K-radiation of sulphur and indicated the presence of K-capture. The branching ratio K/β^- was found to be (l·7±0·1)%. A scintillation spectrometer failed to detect any gamma-ray lines above 20 kev with intensity greater than 10^(-4) of the beta intensity, so the observed K-capture transition goes to the ground state of ^(36)S.