Experimental study of μ-atomic and μ-molecular processes in pure helium and deuterium-helium mixtures -: art. no. 032723

We present experimental results of mu-atomic and mu-molecular processes induced by negative muons in pure helium and helium-deuterium mixtures. The experiment was performed at the Paul Scherrer Institute (Switzerland). We measured relative intensities of muonic x-ray K series transitions in (mu He-3,He-4)(*) atoms in pure helium as well as in helium-deuterium mixtures. The d mu He-3 radiative decay probabilities for two different helium densities in D-2+He-3 mixture were also determined. Finally, the q(1s)(He) probability for a d mu atom formed in an excited state to reach the ground state was measured and compared with theoretical calculations using a simple cascade model.