Observation of four-electron Auger processes

29th International Conference on Photonic, Electronic, and Atomic Collisions

Müller, A.^1 ; Borovik, A.^1 ; Buhr, T.^1,2 ; Hellhund, J.^1 ; Holste, K.^1,3 ; Kilcoyne, A.L.D.^4 ; Klumpp, S.^5 ; Martins, M.^5 ; Ricz, S.^1,6 ; Viefhaus, J.^7 ; Schippers, S.^1,3

Institut für Atom- und Molekülphysik, Justus-Liebig-Universität Giessen, Giessen

35392, Germany^1

Physikalisch-Technische Bundesanstalt, Braunschweig

38116, Germany^2

I. Physikalisches Institut, Justus-Liebig-Universität Giessen, Giessen

35392, Germany^3

Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley

CA

94720-8225, United States^4

Institut für Experimentalphysik, Universität Hamburg, Hamburg

22761, Germany^5

Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen

4001, Hungary^6

FS-PE, DESY, Hamburg

22607, Germany^7

关键词: Absolute cross sections;    Autoionization process;    Branching ratio;    Decay mechanisms;    Four electrons;    Multiple ionization;    Radiative stabilization;    Synchrotron radiation facility;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/635/1/012033/pdf
DOI  :  10.1088/1742-6596/635/1/012033

来源: IOP

【 摘 要 】

Multiple ionization of ions subsequent to absorption of a single photon has been studied employing a photon-ion merged-beam setup at the PETRA III synchrotron radiation facility of DESY in Hamburg. Absolute cross sections for single, double and triple ionization of C+ions were measured with emphasis on specific well defined terms of K-shell excited C+. In particular, the terms C+(1s2s22p2 2D,2P) were excited from the ground level of C+. Subsequent autoionization processes resulted in the production of C2+, C3+and C4+ions. The associated decay mechanisms are single-Auger, double-Auger and triple-Auger decay. The observation of C4+products arising from C+(1s2s22p2 2D,2P) unambiguously confirmed the existence of triple-Auger decay, i.e., a process in which 4 electrons interact with one another such that one fills the K-shell vacancy and the others are simultaneously ejected. The experiment yields branching ratios for the Auger decay channels as well as individual decay rates for autoionization and radiative stabilization of the C+(1s2s22p2 2D,2P) terms.