Azimuthal angular dependence of the K-x-ray emission in swift Ne⁷⁺-Ne collisions

Abstract

In swift near symmetric heavy ion atom collisions the inner shell excitation is well described in the framework of electron promotion between quasi-molecular orbitals transiently formed during the collision process [1]. For K-shell excitation the vacancy transfer via 2p_π-2p_σ-rotational coupling plays a dominating role and yields a characteristic dependence of the 2p_σ-vacancy production probability P_2pσ(b) on the impact parameter (b). The conservation of angular momentum, where angular momentum of the nuclear motion is transfered into electronic angular momentum, creates a significant shape of P_2pσ(b). Systematic experimental investigations [1,2] have shown nice agreement with theory [3,4]. Because of the rotational coupling mechanism the 2p_σ-electron should be promoted only into the 2p_πx-orbital (its angular momentum vector is perpendicular to the scattering plane). If all other 2p_π-states would be vacant, a subsequent x-ray emission from the 2p_πx into the isotropic Is state should reflect by its dipole emission pattern directly this selective 2p_πx-promotion.

supported by DRG