Hydrogen reflection and H α emission

Abstract

In order to investigate the relation between H α emission and the kinetics of reflected particles at a solid surface, D α (656.10 nm) and He I (578.76 nm) spectra emitted from reflected particles under D + and He + bombardment are analyzed in terms of incident ion energy, target material and surface impurity. With increasing incident ion energy, both D α and He I emissions show blue shifts and line broadenings, whereas the total photon intensity decreases. The intensity also increases with the atomic number ( Z number) of the target materials, and the relation between the intensity and Z number is very similar to that found between the reflection coefficients calculated by a Monte Carlo simulation and Z number. From quantitative photon emission measurements, the yield of D α emitting particle normalized to the number of incident deuteron is found to be in the range 10 −2 to 10 −3, depending on the incident energies and target materials. The emission yield is mainly dependent on the velocity of the reflected particles and the effect of electronic structure of target materials, as far as metals are concerned, seems to be small.