(e,2e) processes on atomic targets (Ne, Ar) and molecular targets (CH4, N2, CO2): Role of electron-nucleus scattering

摘要

The momentum distributions of the recoil ions were measured for the single ionization of atomic targetsn(Ne, Ar) and of molecular targets (CH4, N2, CO2) at incident electron energies ranging from 80 to 220 eV by usingnthe reaction microscope. It was found that there are a remarkable number of recoil ions with large longitudinalnmomenta, and the relative contribution of these ions for Ne (e, 2e) reactions decreases faster than that for Arn(e, 2e) reactions with the incident electron energy increasing. This observed feature can be qualitatively interpretednby the different effective potential of the target core experienced by the electrons. The appearance of the largenlongitudinal momentum recoil ions for CH4, N2, and CO2 (e, 2e) reactions indicates that the strong interactionnbetween the electron and the component-atoms target core in the molecules plays a significant role in the singlenionization of small molecular targets. Depending on the independent atom model, we can intuitively understandnthe characteristics of the momentum distributions of the recoil ions CH+n4 , N+n2 , and CO+n2 , respectively.