Mini-EBIS report on electron capture in slow collisions of multiply charged ions with neutral targets

Abstract

The status of cross section measurements carried out with a Mini-EBIS- is reported, here. Single- and multiple-electron transfer processes in collisions of Arq+ (q = 6, 7, 8, 9, and 11) with H2 and He, and those of C4+ with Ne, Ar and Kr have been investigated at low energies ranging from 0.075 eV/amu to 275 eV/amu and from 0.33 eV/amu to 667 eV/amu, respectively. All data of single-electron transfer cross sections measured for Arq+ −H2 and −He systems shows a similar tendency to converge toward the Langevin cross section at the low energy end. In the C4+ −Ne system, double-electron transfer is predominant at high energies and it is dominated by the backward scattering at low energies. From the observation of recoil ions produced in C4+ −Ar and −Kr collisions, it is found that the angular distribution of the multiple-electron transfer collisions shifts toward the backward direction in the center-of-mass frame with decreasing collision energy and four-electron transfer processes take place. The importance of the orbiting effect due to the polarization force and the backward scattering are enhanced in the single- and multiple-electron transfer collisions of highly charged ions at low energies.