Charge state and nonlinear stopping power of heavy ions in a fully ionized plasma

Abstract

Due to the high nonequilibrium charge states specific to heavy ions, the plasma regime with coupling parameters l/ND < 1 and Zp/ND > 1 (ND ∼ number of electrons in a Debye sphere, Zp mean charge state of the projectile) is of interest for the applications. In this regime the stopping power cannot be obtained by a linearization of the Vlasov-Poisson system, but forcing a fully nonlinear treatment. In the present paper the Vlasov-Poisson system is solved numerically by using the capability of the new generation of massively parallel supercomputers. The results are compared with the standard dielectric theory and a binary collision approach. Charge-state calculations are performed, accounting for all relevant features of the atomic processes and the spectra characteristic to heavy ions in dense plasma targets. The results show good agreement with experimental measurement for medium and heavy ions penetrating a Z-pinch device.