Picture of a black hole

Strathclyde Open Access research that creates ripples...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of research papers by University of Strathclyde researchers, including by Strathclyde physicists involved in observing gravitational waves and black hole mergers as part of the Laser Interferometer Gravitational-Wave Observatory (LIGO) - but also other internationally significant research from the Department of Physics. Discover why Strathclyde's physics research is making ripples...

Strathprints also exposes world leading research from the Faculties of Science, Engineering, Humanities & Social Sciences, and from the Strathclyde Business School.

Discover more...

The agreement of Breit-Pauli and Dirac R-matrix collision strengths for iron peak elements: an Fe14+ case study

Berrington, K.A. and Ballance, C.P. and Griffin, D.C. and Badnell, N.R. (2005) The agreement of Breit-Pauli and Dirac R-matrix collision strengths for iron peak elements: an Fe14+ case study. Journal of Physics B: Atomic, Molecular and Optical Physics, 38 (11). pp. 1667-1678. ISSN 0953-4075

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

In calculating collision strengths and excitation rates for electron impact on moderately ionized iron peak elements, one might question whether the Breit-Pauli R-matrix method is sufficiently accurate as compared with the Dirac R-matrix method. We test this for Fe14+ by removing as far as possible any variation in algorithmic features, such as the energy mesh and target state expansion, as opposed to genuine differences between the two approaches. We find the average difference between the Breit-Pauli and Dirac R-matrix effective collision strengths is only 6%, which confirms the hypothesis that if one gets the Dirac and Breit-Pauli target states close, and resolves the resonances adequately (we use up to 384101 points), then the Dirac and Breit-Pauli collision strengths are in good agreement. We finally tabulate the best converged effective collision strengths for T = 10(5)-10(7) K for all transitions involving the lowest 10 levels of Fe14+.