A set of experiments is reviewed which makes use of the emission of mu
onic deuterium from the surface of a layer of solid hydrogen. The beha
viour of muons in a solid target system has been studied via detection
of muon decay electrons, muonic X-rays, and fusion products (neutrons
and charged particles). The emission of muonic deuterium is understoo
d to result from the Ramsauer-Townsend scattering minimum. The energy
distribution of the emitted atoms ranges from tenths of eV to about 10
eV, and can be controlled to some extent. A proposal is described to
use muonic tritium emission to measure the energy dependence of muonic
molecular formation.