Electron-impact excitation of Fe II: Effective collision strengths for optically allowed fine-structure transitions

Journal Article · Sun Nov 15 04:00:00 EST 2009 · Atomic Data and Nuclear Data Tables

DOI:https://doi.org/10.1016/j.adt.2009.08.002· OSTI ID:21333876

In this paper, we present collision strengths and Maxwellian averaged effective collision strengths for the electron-impact excitation of Fe II. We consider specifically the optically allowed lines for transitions from the 3d{sup 6}4s and 3d{sup 7} even parity configuration states to the 3d{sup 6}4p odd parity configuration levels. The parallel suite of Breit-Pauli codes are utilized to compute the collision cross-sections where relativistic effects are included explicitly in both the target and the scattering approximation. A total of 100 LS or 262-jj levels formed from the basis configurations 3d{sup 6}4s, 3d{sup 7} and 3d{sup 6}4p were included in the wavefunction representation of the target, including all doublet, quartet and sextet terms. The Maxwellian averaged effective collision strengths are computed across a wide range of electron temperatures from 100 to 100,000 K, temperatures of importance in astrophysical and plasma applications. A detailed comparison is made with previous works and significant differences were found to occur for some of the transitions considered. We conclude that in order to obtain converged collision strengths and effective collision strengths for these allowed transitions it is necessary to include contributions from partial waves up to L = 50 explicitly in the calculation, and in addition, account for contributions from even higher partial waves through a 'top up' procedure.

• OSTI ID: 21333876
• Journal Information: Atomic Data and Nuclear Data Tables, Journal Name: Atomic Data and Nuclear Data Tables Journal Issue: 6 Vol. 95; ISSN ADNDAT; ISSN 0092-640X
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
APPROXIMATIONS
ASTROPHYSICS
CROSS SECTIONS
ELECTRON TEMPERATURE
ELECTRONS
EXCITATION
FINE STRUCTURE
PARITY
PARTIAL WAVES
PLASMA
RELATIVISTIC RANGE
SCATTERING
WAVE FUNCTIONS