Experimental study of μ --atomic and μ --molecular processes in pure helium and deuterium--helium mixtures
V.M. Bystritsky, V.F. Boreiko, W. Czapliński, M. Filipowicz, V.V. Gerasimov, O. Huot, P.E. Knowles, F. Mulhauser, V.N. Pavlov, N.P. Popov, L.A. Schaller, H. Schneuwly, V.G. Sandukovsky, V.A. Stolupin, V.P. Volnykh, J. Woźniak
Abstract
We present experimental results of
μ
--atomic and
μ
--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 muonic x--ray
K
series transitions relative intensities in
(μ
3,4
He
)
∗
atoms in pure helium as well as in helium--deuterium mixture. The muon stopping powers ratio between helium and deuterium atoms and the
dμ
3
He
radiative decay probability of for two different helium densities in
D
2
+
3
He
mixture were also determined. Finally, the
q
He
1s
probability for a
dμ
atom formed in an excited state to reach the ground state was measured and compared with theoretical calculations using a simple cascade model.