Multibody collision contribution to the slowing down of charged particles through metals

Abstract

Investigating charged particle transport through solid matter is important in those fields, such as particle induced x-ray emission analysis, where quantifying and identifying the reactions produced in the medium are of fundamental interest. A rigorous approach by solving the transfer equation means to face many difficulties most of which arise from the long range nature of the Coulomb interactions, involving more than one particle simultaneously. The common practice of neglecting the multibody collisions, though correct for rarefied neutral gases, often leads to very poor approximations, when charged particles move through dense matter. Here, we discuss a numerical simulation of the Fokker-Planck equation where the multibody collisions are taken into account. The model allows to calculate point-wise the distribution of energy and momentum transferred to the target.