MUON RADIOLYSIS IN ALKALI-HALIDES

In order to shed new light on the initial loss of muon spin polarizati on, or so-called ''missing fraction'', which is commonly observed in n on-metallic solids, we have studied muon-induced excitation in various alkali halides by measuring the lu-minescences associated with the ra diative decay of the self-trapped excitons (STE). The result strongly suggests that the spin-exchange interaction between muonium and muon r adiolysis products including STE's causes fast muon depolarization in those materials.