Single, double, and triple ionization of C(1+) ions by single photons is investigated in the energy range of 286-326 eV, i.e., in the range from the lowest-energy K-vacancy resonances to well beyond ...the K-shell ionization threshold. Clear signatures of C(1+)(1s2s(2)2p(2) (2)D,(2)P) resonances are found in the triple-ionization channel. The only possible mechanism producing C(4+)(1s(2)) via these resonances is direct triple-Auger decay, i.e., a four-electron process with simultaneous emission of three electrons.
Experimental and theoretical cross sections are reported for single-photon single ionization of W5+ ions. Absolute measurements were conducted employing the photon-ion merged-beams technique. ...Detailed photon-energy scans were performed at (67 10) meV resolution in the 20-160 eV range. In contrast to photoionization of tungsten ions in lower charge states, the cross section is dominated by narrow, densely-spaced resonances. Theoretical results were obtained from a Dirac-Coulomb R-matrix approach employing a basis set of 457 levels providing cross sections for photoionization of W5+ ions in the 4 f 14 5 s 2 5 p 6 5 d 2 D 3 2 ground level as well as the 4 f 14 5 s 2 5 p 6 5 d 2 D 5 2 and 4 f 14 5 s 2 5 p 6 6 s 2 S 1 2 metastable excited levels. Considering the complexity of the electronic structure of tungsten ions in low charge states, the agreement between theory and experiment is satisfactory.
Synopsis Electron-impact ionisation cross sections of tungsten ions in the energy range from the ionisation threshold to 1000 eV were measured. The experimental cross sections are compared with ...results from sub-configuration averaged distorted wave calculations. Derived plasma rate coefficients are provided for convenient use in plasma modelling.
Synopsis Photoprocesses of the endohedral fullerene ions Sc3N@C80+ and Sc3N@C80− in the gas phase have been experimentally investigated with emphasis on the specific effects of the encapsulated ...trimetallic nitride cluster Sc3N on the observed reaction yields. Clear evidence of photoexcitation near the Sc L edge is obtained with the dominating contributions visible in the one- and two-electron-removal channels. The experiments are accompanied by model calculations employing density functional theory (DFT).
Cross sections for photoionization and photofragmentation of singly, doubly and triply charged Lu3N@C80 ions have been measured using the photon-ion merged-beams technique at the PETRA III ...synchrotron light source. The measured spectra exhibit prominent resonance features at energies around the carbon K edge. In contrast to that, no signatures of the nitogen K and lutetium M edges have been found in the experimentally investigated reaction channels.
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