Photoionization of tungsten ions: experiment and theory for W4+. (3rd April 2017)

• Record Type: Journal Article
• Authors: Müller, A; Schippers, S; Hellhund, J; Kilcoyne, A L D; Phaneuf, R A; McLaughlin, B M
• Is Part Of: Journal of physics. Volume 50:Number 8(2017:Apr. 15)
• Publication Date: 2017-04-03
• Subjects: photoionization -- tungsten ions -- valence shells -- absolute cross sections -- photon-ion merged-beams techniques -- synchrotron radiation -- many-electron atoms; Atoms -- Periodicals; Molecules -- Periodicals; Optics -- Periodicals; Nuclear physics -- Periodicals; 539.6
• DOI: 10.1088/1361-6455/aa65df
• Languages: English
• ISSNs: 0953-4075

Abstract

Abstract: Experimental and theoretical results are reported for single-photon single ionization of the tungsten ion W 4 + . Absolute cross sections have been measured employing the photon-ion merged-beams setup at the Advanced Light Source in Berkeley. Detailed photon-energy scans were performed at 200 meV bandwidth in the 40–105 eV range. Theoretical results have been obtained from a Dirac-Coulomb R-matrix approach employing basis sets of 730 levels for the photoionization of W 4 + . Calculations were carried out for the 4 f 14 5 s 2 5 p 6 5 d 2 3 F J, J = 2, ground level and the associated fine-structure levels with J = 3 and 4 for the W 4 + ions. In addition, cross sections have been calculated for the metastable levels 4 f 14 5 s 2 5 p 6 5 d 2 3 P 0, 1, 2, D 2 1, G 4 1, S 0 1 . A very satisfying agreement of theory and experiment is found for the photoionization cross section of W 4 + which is remarkable given the complexity of the electronic structure of tungsten ions in low charge states.