Muonium Formation in Noble Gases and Noble-Gas Mixtures

Abstract

In an experiment at the Clinton P. Anderson Meson Physics Facility, no muonium formation was found in pure He or Ne, and abundant formation in Ar and Xe. A small Xe admixture (0.1%) in He and Ne resulted in abundant muonium formation, due to the process in which Xe serves as an electron donor to a low-energy positive muon. These results are qualitatively consistent with our knowledge of relevant atomic collision cross sections.