SCATTERING AND RECOILING IMAGING CODE (SARIC)

A new classical ion trajectory simulation program based on the binary collision approximation has been developed in order to support the res ults of time-of-flight scattering and recoiling spectrometry (TOF-SARS ) and scattering and recoiling imaging spectrometry (SARIS). The code was designed to provide information directly related to the TOF-SARS a nd SARIS measurements and to operate efficiently on small personal com puters. The calculation uses the Ziegler-Biersack-Littmark (ZBL) unive rsal screening function or the Moliere screening function to simulate the three-dimensional motion of atomic particles and includes simultan eous collisions involving several atoms. For TOF-SARS, the program cal culates the energy and time-of-flight distributions of scattered and r ecoiled particles, polar (incident) angle a-scans, and azimuthal angle delta-scans. For SARIS, the program provides images of the scattering and recoiling intensities in polar exit angle and azimuthal angle (be ta, delta)-space. A two-dimensional reliability factor (R) has been de veloped in order to obtain a quantitative comparison of experimental a nd simulated images. Examples of simulations are presented for Ni{100} , {110} and {111} surfaces and a Pt{111} surface. The R-factor is used to quantitatively compare the simulated Pt{111} image to an experimen tally emulated image.