AN APPARATUS FOR ION-SURFACE COLLISIONAL PROCESS STUDIES AND SURFACE-ANALYSIS

An experimental setup allowing both surface and interface analysis and ion-surface collisional process studies is described. It consists of an ion beam line which provides 1-80 keV mass analysed rare gas and al kali-metal ions, and an UHV chamber. This one is equipped with two tim e of flight systems which allow energy and mass analysis of scattered and recoiled particles at scattering angles 180 degrees and in the ran ge 0-165 degrees. In addition a fixed electrostatic hemispherical anal yser can record either the positive ions or the emitted electrons, at an angle of 90 degrees from the ion beam. The versatility of the appar atus is illustrated with data on dean Si (111) surface and on impurity - or Cs-covered Si surface: chemical and crystallographic structure an alysis, depth profile, ion fractions and ion-induced electron spectros copy.