Free Access
Astron. Astrophys. Suppl. Ser.
Volume 142, Number 2, March I 2000
Page(s) 313 - 316
Published online 15 March 2000
DOI: 10.1051/aas:2000152

Astron. Astrophys. Suppl. Ser. 142, 313-316

Atomic data from the IRON Project

XLI. Electron excitation rates among the 3d2 fine-structure levels of Ca-like Fe VII

K.A. Berrington1 - S. Nakazaki2 - P.H. Norrington3

1 - School of Science & Mathematics, Sheffield Hallam University, Sheffield S1 1WB, UK
2 - Department of Materials Science, Faculty of Engineering, Miyazaki University, Miyazaki 889-21, Japan
3 - Department of Applied Mathematics & Theoretical Physics, Queen's University, Belfast BT7 1NN, UK

Received July 30; accepted October 22, 1999


Electron excitation collision strengths of 3d2fine-structure transitions in Ca-like Fe VII are calculated using an R-matrix method, which included the 80 terms arising from the 3d2, 3d4s, 3d4p, 3d4d, 3d4f and 3p53d3 configurations. Extensive autoionizing resonance structures together with channel coupling is therefore explicitly included; relativistic effects are accounted for by a term-coupling transformation. A thermal average is taken to obtain the effective fine-structure collision strength as a function of electron temperature T, for log T(K) = 4.3-6. Open 3p-shell resonances are seen to considerably enhance the background collision strength, by several factors for some of the 3d $^{2}_{j\rightarrow j'}$ transitions.

Key words: atomic data

Copyright The European Southern Observatory (ESO)

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.