Influence of laser field on stopping power of energetic ions in solids

We study the influence of a high-intensity laser field on inelastic interac tions between a swift ion and a solid target, describing the excitations of the electron gas in the target by the hydrodynamic model. By linearizing t he hydrodynamic equations, we derive general expressions for the induced po tential and the ion stopping power which depend on the intensity and the fr equency of the laser. For high-velocity ions, semi-analytical expressions f or the stopping power are obtained and the effects of the laser field on th e stopping power are discussed. Moveover, the Barkas (or Z(1)(3)) effect on the stopping power is evaluated within the second-order perturbation appro ach to the hydrodynamic equations, and its dependance on laser frequency is described. (C) 2001 Published by Elsevier Science B.V.