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Title: Energy loss of heavy ions in dense plasma. II. Nonequilibrium charge states and stopping powers

Journal Article · · Physical Review, A; (USA)
;  [1]
  1. Max-Planck-Institut fuer Quantenoptik, D-8046 Garching, Federal Republic of Germany (DE)

The effective charge {ital Z}{sub eff} of fast heavy ions slowing down in hot dense matter is calculated simultaneously with the stopping power {ital dE}/{ital dx}. The various ionization and recombination processes determining {ital Z}{sub eff} are discussed, and corresponding rate coefficients are given; particular attention is paid to dielectronic recombination which turns out to be the dominant capture mechanism in highly ionized target material. Important results are (1) the effective charge of heavy ions passing through matter is considerably higher for fully ionized plasma than for cold target matter; (2) in contrast to stopping in cold targets, where {ital Z}{sub eff} runs through a series of equilibrium charge states essentially determined by the instantaneous projectile velocity, high nonequilibrium charge states of the projectile are found in strongly ionized targets due to reduced recombination and faster stopping; (3) this causes additional range shortening, in some cases by factors 2--7, in particular for relatively low projectile energies ({ital E}{sub ion}{lt}2 MeV/u) and target densities ({ital n}{lt}10{sup 20} cm{sup {minus}3}). Typical results for {ital Z}{sub eff} and {ital dE}/{ital dx} in this parameter region are presented. They are compared with recent experimental data; new experiments are proposed. Concerning applications to heavy-ion-driven inertial fusion, the described effects become relevant at the end of the range, and some illustrative cases are discussed.

OSTI ID:
5906249
Journal Information:
Physical Review, A; (USA), Vol. 43:4; ISSN 1050-2947
Country of Publication:
United States
Language:
English