Double-K-vacancy states in electron-impact single ionization of metastable two-electron N5+(1s2s 3S1) ions

The role of hollow states intermediately produced in electron-impact ionization of metastable He-like N5+(1s2s3S1) ions has been investigated in detail. A crossed-beam setup and suitable experimental techniques were employed for the measurement of accurate absolute cross sections and precise energy-...

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Bibliographic Details
Main Authors: Mϋller, A., Borovik, A., Huber, K., Schippers, S., Fursa, Dmitry, Bray, Igor
Format: Journal Article
Published: American Physical Society 2014
Online Access:http://hdl.handle.net/20.500.11937/23527
Description
Summary:The role of hollow states intermediately produced in electron-impact ionization of metastable He-like N5+(1s2s3S1) ions has been investigated in detail. A crossed-beam setup and suitable experimental techniques were employed for the measurement of accurate absolute cross sections and precise energy-scan data. Fine structures arising from K-shell excitations and associated resonances have been observed for this two-electron ion with less than ±0.5 eV uncertainty on the energy scale. Fine details, such as interference of the reaction pathways of direct ionization and excitation with capture of the incident electron followed by double-Auger decay, could be revealed. Ab initio calculations based on the convergent close coupling (CCC) approach are in good agreement with the experiment.