Stopping of low-energy highly charged ions in dense plasmas

Abstract

Stopping power of low-energy, highly charged projectiles in cold dense plasmas was numerically investigated to search realistic parameters for beam–plasma interaction experiments using ≈10–100 keV/u projectiles delivered by a 1.7 MV electrostatic accelerator. In order to evaluate the energy loss, a simple Molecular Dynamics (MD) computer code was applied. If the projectile velocity was as low as the thermal velocity of plasma electrons, and the projectile charge was sufficiently high, nonlinear stopping was observed even for weakly nonideal plasma targets with Γ ≈ 0.1 . According to a numerical analysis on the charge state distribution coupled with an energy loss calculation, projectiles with such a high charge state are rapidly lost by the strong recombination owing to electrons loosely trapped by the projectile, as well as the residual hydrogen atoms in the plasma.