STRONG PROJECTILE-ENERGY DEPENDENCE OF THE AUGER-LINE INTENSITY AT 0-DEGREES DUE TO COULOMB FOCUSING IN FAST PROTON-NEON COLLISIONS

The variation of the intensity of the Ne K-L(2,3)L(2,3)(D-1(2)) Auger line due to postcollision interaction has been measured as a function of the projectile energy at 0 degrees (+/- 1.4 degrees) observation an gle in 0.8-3.2 MeV H+-Ne collisions. The-measured Anger-electron yield normalized to the theoretical or experimental total K-shell ionizatio n cross section shows a strong enhancement when the projectile velocit y is smaller than the Auger-electron velocity. The general agreement b etween the present experimental data and continuum distorted wave calc ulations provides a clear evidence that the observed impact-energy dep endence is mostly due to the post-collision Coulomb focusing exerted b y the projectile on the Auger electron.