Experimental and theoretical studies of theHe2+-He system: Differential cross sections for direct, single-, and double-charge-transfer scattering at keV energies

Abstract

Measurements and calculations of differential cross sections for direct scattering, single charge transfer, and double charge transfer in collisions of 1.5-, 2.0-, 6.0-, and 10.0-keV 'He + with a He target

Theoretical atomic collision physics

“…A paper is in preparation for publication. 61 We have completed calculations of cross sections and rates for quasi-resonant charge transfer in very low-energy collisions, e.g. T=8K to 80K, of 3He+ + 4Iqe (endotherrnic) and 4He+ + 3He (exothermic), using the theory of Thorson and Dclos 76,77 In comparison with the recent experiments of Schauer et.…”

Single- and double-charge transfer in slow He2+–He collisions

“…The interest of these studies was focused particularly on the one-and two-electron capture processes, at both low and high collision energies. Since in this study we shall be interested in the low-energy dynamics of these two processes, we mention here only the most extensive studies performed in the energy region below ∼20 keV/u either experimentally [3][4][5][6][7][8][9][10][11][12][13][14][15] or theoretically [16][17][18][19][20][21][22][23][24][25][26]. The theoretical description of atomic collision processes in this energy region normally requires a molecular representation of electronic states, with the nuclear motion described classically (for energies above ∼0.2 keV/u) or quantum mechanically (for energies below ∼0.2 keV/u).…”

“…A two-electron atomic orbital close-coupling (2e-AOCC) method has also been applied to electron capture processes in the He 2+ -He collision system [22,23] for energies extending down to ∼1 keV/u. We also mention that in [10] the MOCC method was used with the quantum-mechanical description of nuclear motion (QMOCC) for calculation of differential cross sections for single-and double-electron capture processes, as well as for the elastic scattering, employing however a very limited expansion basis (six states for the single-electron capture and two states for the two-electron capture).…”

“…In contrast to the numerous studies of integral SCT and DCT cross sections in He 2+ -He collisions, the differential cross sections of one-and two-electron capture processes in this collision system are rather scarce. Gao et al [10] have measured the SCT, DCT and the direct scattering (DS) differential cross sections for collision energies of 1.5, 2, 6 and 10 keV for 3 He 2+ colliding with 4 He target. Afrosimov et al [6] and Bordenave-Montesquieu and Dagnac [12] (hereafter referred to as B-MD) measured the differential state-selective SCT cross sections at projectile energies of 2-8 keV in 4 He 2+ -4 He collision system.…”

Fully Differential Study of Transfer Ionization Processes?a View into Correlated Many Particle Dynamics

“…Since the single electron capture is related to the population of other molecular states, these have to be included into the basis, but also those calculation are feasible since the late seventies [3]. In the more recent work of Gao et al [4] a fully quantum-mechanical molecular-orbital treatment using the Born-Oppenheimer approximation was used to achieve agreement between theoretical and experimental results for the single differential cross section, also at very small scattering angles.…”