Generation of slow positive muons from solid rare-gas moderators.

We observe the emission of slow ( 50 eV) positive muons (micron sup +) from solid neon, argon, krypton and xenon moderators exposed to a 4.2 MeV incident micron sup + beam. The time of flight spectra for all of the targets studied exhibit a peak with an approximate FWHM of 10 ns, corresponding to an energy spread of about 50 eV. Little or no evidence for diffusion was observed, suggesting a "hot muon" emission mechanism. Of the targets measured, argon was observed to produce the highest yield [(1.8 +- 0.23) X 10 sup (-5) slow micron sup + per incident micron sup +], providing a useful flux for further experimentation.