Theoretical Investigation on Excitation, Ionization and Capture in H(1 s , 2 s ) + H(1 s , 2 s ) Collisions

Abstract

Cross sections of electron-loss in H(ls)+ H(ls) collisions and total collisional destruction of H(2s) in H(ls) + H(2s) collisions are calculated by four-body classical-trajectory Monte Carlo (CTMC) method and compared with previous theoretical and experimental data over the energy range of 4–100 keV. For the former a good agreement is obtained within different four-body CTMC calculations, and for the incident energy Ep > 10keV, comparison with the experimental data shows a better agreement than the results calculated by the impact parameter approximation. For the latter, our theory predicts the correct experimental behaviour, and the discrepancies between our results and experimental ones are less than 30%. Based on the successive comparison with experiments, the cross sections for excitation to H(2p), single- and double-ionization and H- formation in H(2s)+H(2s) collisions are calculated in the energy range of 4–100keV for the first time, and compared with those in H(ls)+H(ls) and H(ls)+H(2s) collisions.

Excitation cross sections in a collision between two ground-state hydrogen atoms

“…Figure 7 shows our present excitation cross sections of the target from the 1s state into the 2p state as a function of impact energy. Figure 7 also shows the previous results of the 2p target excitation channels by CHEN Lan-Fang et al [20], using the CTMC calculation, and by Bottcher and Flannery [14], using the four-state symmetrised exchange calculation. It can be seen that the present CTMC results for 2p target excitation cross sections are close to the previous classical simulation of CHEN Lan-Fang et al [20].…”

“…Figure 7 also shows the previous results of the 2p target excitation channels by CHEN Lan-Fang et al [20], using the CTMC calculation, and by Bottcher and Flannery [14], using the four-state symmetrised exchange calculation. It can be seen that the present CTMC results for 2p target excitation cross sections are close to the previous classical simulation of CHEN Lan-Fang et al [20]. Moreover our present results are in good agreement with the experimental data of Morgan et al [21].…”

“…Red circles: presents CTMC results for 2p excitation cross sections of the target, defined by equation (17). Green triangles: the CTMC calculation by CHEN Lan-Fang et al [20]. Dark yellow dashed-double-dots: four-state results of Shingal et al [18].…”