Inelastic processes in 1-1000 keV/u collisions of Be^q+(q= 2–4) ions with atomic and molecular hydrogen

Abstract

Owing to the use of beryllium in fusion reactors and the consequent need to model and diagnose plasmas containing this species of impurity, cross sections are presented here for inelastic collisions of 1-1000 keV/u Be q+ (q=2-4) with H and H 2. In particular, the classical trajectory Monte Carlo technique is used to compute total cross sections for (i) ionization, (ii) state-selective excitation, and (iii) state-selective charge transfer.

Charge transfer cross section calculation and evaluation for Be[sup q+]+H collisions

“…The 'underestimation' of the total capture cross section by the CB approximation is due to the fact that only the contribution of n=2 and n=3 channels was included in the total cross section. The n-state-selective cross sections for electron capture to the Be + (1s 2 nl)(n=2,3,4) states obtained by the QMOCC and AOCC methods are shown in figure 4, and compared with the PSS results [15], CTMC results [12] and CB results [13]. Our QMOCC results are coincident with the AOCC results and the PSS results [15] on the whole.…”

“…On the theoretical side, systematic cross section calculations for the Be q+ +H (q=2-4) charge exchange collisions have been performed using the classical trajectory Monte Carlo (CTMC) method by Schultz et al [12]. The CoulombBorn (CB) approximation and the boundary corrected continuum intermediate state (BCCIS) approximation are employed by Das et al [13,14] for q=1-3 and for q=1-4, respectively, in the energy range of 25-200keV/u for the total cross section and in the range of 40-200 keV/u for the state-selective cross sections.…”

“…Except our works, the perturbed stationary states (PSS), classical trajectory Monte Carlo (CTMC) and CB methods were employed to study electron capture process by Wetmore et al [15], Schultz et al [12] and Das et al [13,14] at energies above 0.05keV/u.…”

“…The results obtained by the CTMC [12], PSS [15] and CB [13] methods are shown in the same figure for comparison. It can be seen that our QMOCC and AOCC results are in good mutual agreement in the overlapping energy range, as well as with the PSS results of Wetmore et al [15] up to energies of about 3keV/u.…”

X-ray and extreme ultraviolet emissions from comets

“…In particular, it can provide data for a large number of n, l states. While the method was primarily developed for single-electron ion-atom, i.e., bare-ion plus H, collisions, it has been extended to treat H 2 targets (Meng et al, 1990;Schultz et al, 1996) and partially-stripped ions Raković et al, 2001). CTMC is a very robust method for providing the necessary SEC data relevant to EUV/x-ray emission from Jupiter since the collision energies of the precipitating ions are greater than 10 keV/u.…”