Deterioration of Luminescent Phosphors under Positive Ion Bombardment

The reduction of cathodoluminescence efficiency of phosphors has been observed after bombarding with H+, H2+, He+, Ne+, N2, and A+ ions having energies from 1 to 25 kev. Detectable deterioration could be observed after a bombardment of less than 10−9 coul/mm2 of ions (5×1011 ions/cm2). The deterioration could be annealed out at temperatures between 450° and 700°C. Results indicate that light 25-kev ions probably penetrate 0.1μ to 0.2μ into the phosphor.