Auger transition probabilities and electron emission cross sections for vacancy decay into the 2$p\pi$-orbital in the Ne$^+$–Ne quasimolecule

The paper reports the calculation of the probabilities of Auger transitions taking place in the process of filling a vacancy on the 2$p\pi$-orbital in an Ne$^+$–Ne quasimolecule, a short-lived system which arises when the ion and atom approach each other and decays when they fly apart. Calculations for various ionization degrees of the quasimolecule particles were performed for the first time. It was found out that the system ionization degree increases very significantly (from 2 to 6) with increasing collision energy and decreasing distance of the particles closest approach. Using of the quantum mechanical approach and taking into account the collision dynamics made it possible to quantitatively describe for the first time the experimental Auger electron spectra of a complex many-electron quasimolecule. The contribution of the transition from the initial 3$d\pi$–3$d\pi$ state to the 2$p\pi$ orbital was shown to be predominant among the whole variety of possible Auger decay channels.