Local field corrections vs. Mermin dielectric function on proton stopping in plasmas

The energy loss of charged particles in a free electron gas is of considerable interest to actual slowing-down problems. This is a topic of relevance to understand the beam-target interaction in the contexts of particle driven fusion. The energy losses of ions moving in an electron gas can be studied through the stopping power of the medium. Large number of calculations of the stopping power of ions and electrons in plasmas has been carried out using the random phase approximation (RPA) in the dielectric formalism. The RPA is usually valid for high-velocity projectiles and in the weak coupling limit of an electron gas. But for partially coupled plasmas, which are subject of much interest for current studies of ICF, RPA it is not sufficient and electron collisions have to be taken into account. In this report electron collisions will be treated through two different ways: the Mermin function or the local field corrections (LFC). Mermin [1] derived an expression for the dielectric function taking account these electron collisions and also preserving the local particle density