ELECTRIC-FIELD DEPENDENCE OF MUONIUM ATOM FORMATION IN SOLID NITROGEN

Muon spin precession signals arising from both muonium (mu(+)e(-) or M u) and diamagnetic muon species have been studied in condensed molecul ar nitrogen in the temperature range 10-78 K. Muonium is formed both i n ''prompt'' epithermal processes and in ''delayed'' convergence of th e thermalized mu(+) with an electron from the muon ionization track. T he latter process is strongly correlated with changes in the electron mobility in solid N-2; it is inhibited by an electric field E similar to 3.5 kV/cm applied in the direction of the muon motion and enhanced by a comparable electric field in the opposite direction, indicating t hat the pf stops on average about 60 nm ''downstream'' of the e(-) lib erated in its last ionization of the medium.