Nemeth A. Excitation and dielectronic recombination of zinc and cadmium ions at electron-ion collisions

Object of investigation: The role of subvalent (n-1)d10 - shell in the mechanisms of excitation and dielectronic recombination of zinc and cadmium ions at collisions with slow electrons. Aim of studies: Elucidation of general regularities and peculiarities of excitation and dielectronic recombination of zinc and cadmium ions at collisions with monoenergetic electrons and clarification of the influence of relativistic, correlation and resonant effects on the mechanisms of these processes. Method of investigation: method of orthogonal crossed electron and ion beams with observation of radiation at the right angle to the crossing-beam plane combined with photon spectroscopy. Scientific novelty of the results. The resonant excitation of separate componenets of the resonant doublet of the ions under investigation is shown to be related mostly to the electron decay of atomic autoionizing states being formed at the capture of the incident electron by an ion with simultaneous excitation of the ion electron from the subvalent (n-1)d10 - shell. The structure at the excitation functions below the excitation thresholds for the resonant levels of Zn+ and Cd+ ions is shown to result from the dielectronic satellites which essentially distort the real behaviour of the resonant line excitation function at the threshold. At the collisions of electrons with Cd+ ions radiation with maximal efficiency at the wavelength l = 325.4 nm at the electron energy 3.81 eV is revealed, resulting from the radiative decay of Cd (4d9 5s2 5p) 1P1 autoionizing states to the Rydberg 4d10 5s nl - levels of Cd atom in the dielectronic recombination process. A considerable contribution of resonant processes into the excitation of Zn+ and Cd+ ions and high probability of the dielecronic recombination of these ions at their collisions with monoenergetic electons are shown to be related to the essential influenece of relativistic and correlation effects upon the mechanisms of these processes. Implementation: planned. Sphere of application: plasma physics, astrophysics, quantum electronics.