LUMINESCENCE OF SELF-TRAPPED EXCITONS INDUCED BY SINGLE KEV ION-BOMBARDMENT

We have studied the light emission from CsI and NH4Cl films that were bombarded simultaneously with H-, low mass organic, and (CsII- (n = 0- 2) ions in the keV energy range (25-45 keV) at room temperature. Photo ns were detected from the impact of individual primary ions with a sin gle photon counting photomultiplier, and were analyzed using time reso lved and wavelength analysis. For CsI, fast (tau less than or equal to 12 ns) and slow (tau greater than or equal to 650 ns) component decay s were observed for all projectiles used. The fast component's emissio n was similar to 300 nm while the slow component's emission was in the visible. Only a fast component (tau < 3 ns) was observed in the UV re gion for NH4Cl. Our data suggest that the light emission from both sam ples is due to the radiative relaxation of serf-trapped excitons which are produced by electronic interactions between the primary ions and the target atoms.