TOF analysis of reflection of low-energy light ions from solid targets using coaxial impact collision ion scattering spectroscopy (CAICISS)

The energy spectra of He and D particles reflected from the Si(1 1 1)-3×3 Sb surface at the angle of π in the sub-keV regime have been studied by means of a CAICISS system. The quantum efficiency of the microchannel plate for the particle detector in the CAICISS system has been determined as a function of the kinetic energy from the comparison of the experimental peak intensity from Sb atoms in the sub-monolayer regime with the theoretical one. The latter is calculated by use of the elastic scattering cross-section derived from the Thomas–Fermi model of the screened Coulomb potential. The energy spectra of He particles backscattered from the Si(1 1 1) substrate on incidence of 2 keV He+ ions have been also obtained by use of the quantum efficiencies determined and compared with the theoretical ones calculated on the large angle single deflection model.