INELASTIC MEAN FREE-PATH OF H-TO-100 KEV IN CARBON-FILM( AND HE+ WITHTHE ENERGY OF SIMILAR)

The energy loss distributions of H+ and He+ with similar to 100 keV tr ansmitted through carbon films with a thickness of similar to 6 nm hav e been measured by means of high-resolution (similar to 30 eV) ion ene rgy loss spectroscopy. The zero energy loss peaks have been observed. The presence and effect of pinholes in films is inferred from the H-2( +) transmission yield. Assuming that the intensity ratio of the zero e nergy loss peak over the sum of this peak and the main energy loss pea k follows an exponential decrease with the film thickness, the inelast ic mean free path was derived as 0.6 and 0.9 nm for H+ and He+ at 100 keV and these values are compared with the experimental values for equ ivelocity electrons and also with the calculated values for equiveloci ty electrons, positrons and protons.