Electronic sputtering of nitrogen from carbon induced by swift highly charged ions

Electronic sputtering of nitrogen on carbon was studied as a function of the electronic energy loss dE/dx and the projectile charge q with swift highly charged heavy ions (Z=6-73, q=6-54, E=6-13 MeV/u). The fluence dependence of low energy electron yields induced by swift heavy ions allows to deduce the cross section σN2/C for sputtering of nitrogen from carbon. A strong correlation of this desorption cross section (or the sputtering yield) is found with the parameter dE/dx and in a lesser extend with q. The dependence on q is close to the cubic charge dependence observed for the emission of H+ secondary ions which are believed to be emitted from the very surface. On the other hand, the dependence on dE/dx is close to a quadratic one thus rather pointing towards a thermal evaporation-like effect. (orig.)