Classical and semi-classical treatments of Li³⁺, Ne¹⁰⁺+H(1s) collisions

Abstract

We perform molecular close-coupling and impact-parameter classical trajectory Monte Carlo calculations of total and partial cross sections for capture and ionization in collisions of highly charged ions on H(1s). We first consider Li3++H(1s) as a benchmark to ascertain the complementarity of the methods, and then Ne10++H(1s), which has been scarcely studied up to now, and has recently become of interest for fusion plasma research.

Calculation of ionization and total and partial charge exchange cross sections for collisions of C6+ and N7+ with H

“…For the lowest n levels shown in Fig. 8, the microcanonical CTMC partial cross sections agree with the semiclassical data, but, as the collision energy increases the microcanonical cross sections show an unphysical rapid fall as n increases, as it was found in previous works [29][30][31]33].…”

“…Similar comparisons for H(n=1) can be found in reference [29]. Previous calculations on Li 3+ , B 5+ and Ne 10+ + H collisions [30,29,33] showed that the hydrogenic-CTMC treatment provides accurate ionization and total and n-resolved electron capture cross sections for n n max , where n max is the most populated level of the ion A (q−1)+ formed in the CX reaction. The microcanonical-CTMC treatment leads in general to more accurate CX cross sections into low-lying states, as explained in detail in [29].…”

“…13 we have plotted the present hydrogenic CTMC total CX cross sections for C 6+ and N 7+ projectiles colliding with ground-state and excited hydrogen atoms. together with those for Li 3+ and Ne 10+ + H(1s) [30] and for Ar 18+ + H(1s) collisions [31], obtained with a similar approximation. We can observe a correct behaviour of the scaling law suggested by Foster [9].…”

“…However, it has been shown that the CTMC method [28,23,29] provides reliable total cross sections for all processes at E 15 keV/amu. In particular, the use of improved initial distributions has allowed to evaluate state selective CX cross sections for several systems [30][31][32][33], which have been merged with semiclassical calculations to provide sets of recommended data. This method has been recently applied to calculate excitation cross sections in [34].…”

Plasma code for astrophysical charge exchange emission at X-ray wavelengths

“…In the high-speed regime (v ∼ v 0 ), the collision dynamics become more important for the capture process, and the peak population level is gradually smeared out among several adjacent shells. We compiled the velocity-dependent, n-resolved cross sections for reactions involving Be, B, C, N, O, Ne, and Fe ions from theoretical calculations (Ryufuku 1982;Shipsey et al 1983;Fritsch & Lin et al 1984;Belkić et al 1992;Toshima & Tawara 1995;Harel et al 1998;Raković et al 2001;Errea et al 2004;Nolte et al 2012;Wu et al 2011Wu et al , 2012Mullen et al 2015). As shown in Fig.…”