BACKSCATTERING OF NITROGEN-IONS FROM A COLD NICKEL SURFACE COVERED WITH CONDENSED RARE-GASES UNDER N-2(-BOMBARDMENT() ION)

Energy spectra of dissociated nitrogen ions scattered from a cold (100 ) nickel surface covered by films of condensed rare gases under N-2(+) ion bombardment were examined at chosen values of angles between axis of ion beam and the target surface (incidence angles) and different d ensity of films. An extremly large broadening of the energy spectrum o f dissociated nitrogen ions at a detection angle of Theta = 150 degree s (with respect to the axis of ion beam) was found, that was inconsist ent with existing models. It is assumed that the broadening of the ene rgy spectrum is, first, a result of registration of the ions which hav e been scattered from the substrate atoms over angles smaller than the detection angle and then multiply scattered inside the film of conden sed gases, causing them to be directed to the detector. Secondly, broa dening additionally arises from redistribution of the kinetic energy b etween partners of the bombarding molecule. Copyright (C) 1996 Elsevie r Science Ltd