Muon spin resonance and pulse radiolysis studies of liquid CS 2

Abstract

An extensive study of positive muon chemistry has been performed in order to clarify the mechanism of the large loss of the muon spin polarization in CS 2. The main technique used in the experiments was “muon spin resonance”. After a brief demonstration of the usefulness of the resonance method, its application to the study of both the diamagnetic muon and the muonium-substituted free radicals in CS 2 are described. The results show an existence of muonium-substituted free radicals in CS 2, but they were stable only in limited conditions. The diamagnetic muon fraction, which is only about 0.2 at first, was found to increase slowly with time. This kind of slow formation of the muon state has been found for the first time by the resonance method in CS 2. From the combination of the obtained results, we infer that the loss of the muon spin polarization is due to reactions of the muonium-substituted free radicals, for which aggregation effect of the substance plays an important role. Results of nanosecond pulse radiolysis of CS 2 are also presented compared with the results of the muon chemistry.