QUASI-DISCRETIZATION OF THE ELECTRON CONTINUUM EMITTED IN COLLISIONS OF 0.6MEV U(-1)AU-11+ WITH NOBLE-GASES

We have measured relative doubly-differential cross sections for electron emission in collisions of 0.6 MeV u-1 Au11+ projectile ions with He, Ne and Ar targets for laboratory electron-detection angles between 17-degrees and 80-degrees and electron energies from 100 eV to well above the classical binary encounter region. We observe that, independent of the target Z(t), the electron spectra display three characteristic peak-like structures whose energies are nearly invariant with observation angle. These structures are attributed to the diffraction of quasi-free target electrons in the potential of the projectile.