Energy loss of heavy ions in dense plasma : I. Linear and nonlinear Vlasov theory for the stopping power
The plasma physics of heavy-ion stopping in fully ionised matter is developed on the basis of the Vlasov-Poisson equations. Particular emphasis is placed on small ion velocities v(p) below the electron thermal velocity v(th) and on nonlinear solutions in the coupling parameter Z = Z(eff)/(n(0)lambda(3,D) between the heavy-ion projectile with effective charge Z(eff) and the plasma with electron density n(0) and Debye length lambda(D). Concerning the stopping power in the low-velocity regime relevant for the Bragg peak at the end of the ion range, results on the friction term dE/dx proportional to v(p) are presented, and an improved dE/dx formula for plasma is derived in a closed form which is readily applicable for stopping power calculations. For v(p) less than v(th), nonlinear results are found to contribute to the stopping power with terms proportional to Z(5/2) for positive ions and terms proportional to Z3 for negative ions, in addition to the basic Z2 term. At high velocities with v(p) greater than v(th), the relevant coupling parameter is Z(v(th)/v(p))3, and nonlinear corrections to the stopping power proportional to Z3/v(5,p) are obtained by extending the work of Ashley, Ritchie and Brandt to the plasma case. An interpolation between the low- and the high-velocity results is given. The application of the present results to heavy-ion energy loss in an electron-cooling line is also discussed.
Bibliographic Reference: Article : Physical Review A, Vol. 43 (1991) No. 4, pp. 1998-2014
Record Number: 199111093 / Last updated on: 1994-12-02
Original language: en
Available languages: en