SIMULTANEOUS DETECTION OF SECONDARY IONS AND PHOTONS PRODUCED BY THE IMPACT OF KEV POLYATOMIC IONS

(CsII-(n = 0-3), low mass organic negative clusters, and H-, in the 20-46 keV energy range, have been used in time-of-flight secondary ion mass spectrometry (TOF-SIMS) experiments to study the relationships between secondary ion and photon emission from a surface. We report on the simultaneous detection of secondary ions and photons produced by the impact of keV polyatomic ions. Our results indicate that, for a CsI target, secondary ions and photons are produced independently of each other through different mechanisms. Secondary ion emission is strongly dependent upon the complexity of the primary ion, i.e. monoatomic or polyatomic. However, photon emission appears to be independent of the primary ion's complexity and depends primarily upon the velocity of the primary ion. Unlike the secondary ion yields, no yield enhancements for the photons were observed due to polyatomic primary ions. Only broad band light emission from the bulk of the target was observed; no line emissions from sputtered species were detected. We compare the yields of both secondary ions and photons that were collected simultaneously, and present a simple model that describes the observed photon yields as a function of both the electronic and nuclear stopping powers of the primary ion.