Absolute cross sections for L-shell photoionization of the ions N, N, O, O, F, F and Ne

¹ Laboratoire d'Interaction des Rayons X avec la Matière (LIXAM), UMR 8624 du CNRS, University Paris-Sud, Bât. 350, 91405 Orsay, France e-mail: jean-marc.bizau@lixam.u-psud.fr
² Department of Physics and Astronomy, University of Aarhus, 8000 Aarhus C, Denmark e-mail: kjeldsen@phys.au.dk
³ Laboratoire de Chimie Physique- Matière et Rayonnement (LCP-MR), Université Pierre et Marie Curie, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France
⁴ CEA/DAM Ile-de-France, Département de Physique Théorique et Appliquée, BP 12, 91680 Bruyères-le-Châtel, France

Received: 5 January 2005
Accepted: 4 February 2005

Abstract

Absolute photoionization cross sections for the ions N²⁺, N³⁺, O³⁺, O⁴⁺, F³⁺, F⁴⁺ and Ne⁴⁺ are measured using the merged-beam technique, combining the synchrotron radiation from an undulator at the storage ring ASTRID with ions produced by an ECR ion source. The spectral structures and the development of the cross sections along iso-electronic sequences are discussed. The experimental data are compared with R-matrix calculations from the Opacity Project and other sources, MCDF calculations, as well as the model functions provided by verner et al. (1996). In general, good agreement between experiment and calculations is observed for the magnitude of the continuum cross sections whereas very significant discrepancies are present for the resonance structures. The experimental data are also available in electronic form at the CDS.