Observation of low energy mu(+) emission from solid surfaces.

Energetic positive muons were injected into the back of thin moderators (Lithium-Fluoride, Quartz and Copper), and the transmitted beam energy analyzed. The mu(+) time of flight spectra for Lithium-Fluoride and Quartz were observed to have two components; a narrow distribution of slow (10 eV) mu(+) (rate = (1.6 +- 0.35)x10(-7) per incident mu(+) for Lithium- Fluoride) and a broad epithermal component (0-2 keV), while the data for Copper indicated only an epithermal contribution. Slow (10 eV) negative muonium ions (mu(+)e(-)e(-) were also observed for the first time in vacuum.