Electron impact single ionization of the He-isoelectronic sequence

Abstract

In this work, triply differential cross sections for single electron emission due to electron impact on the Heisoelectronic sequence are calculated by using a Born-C3 model. The influence of the nuclear charge on the angular distributions is analyzed. The validity of a scaling law initially derived in the framework of photodouble-ionization is discussed.

Theoretical study of the double ionization of the He isoelectronic sequence by protons and antiprotons

“…The remaining point to consider is the possible existence of an overall magnitude scaling for the FDCS as found in photo -double-ionization studies and (e,2e) studies [28][29][30][31][32]. In first place we discuss whether the initial state, the final state and the transition matrix scale with Z T or not.…”

“…Hence, the explicit inclusion of the interelectronic interaction distorts any possible scaling behavior [32]. As Z T increases, it is well known that the relevance of the electron-electron interaction decreases in the initial state [28,31,33]. From the analysis we performed above for Fig.…”

“…From the Schroedinger equation for the present 4-body problem, it is possible to obtain, in the large Z T limit, a charge independent universal equation in which the projectile and electrons energies scale with the square of the nuclear charge [28,[30][31][32]42]:…”

“…In third place, we analyze the scaling properties of the FDCS. In previous works, scalings for the FDCS for different target nucleus charges were calculated for different processes as atomic photo-double-ionization (PDI) of two electron ions [28,29], single ionization of atoms by electron impact [30,31] or double ionization of the isoelectronic series of He by electron impact [32,33]. In this work we contribute to the subject by showing the substantial differences that arise in the angular distributions when low nuclear charges are considered in a scaled regime.…”