Electron impact excitation of Al XIII: A relativistic approach^*

¹ Department of Pure and Applied Physics, The Queen's University of Belfast, Belfast BT7 1NN, Northern Ireland, UK e-mail: K.Aggarwal@qub.ac.uk
² Department of Physics, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK

Received: 10 November 2004
Accepted: 29 November 2004

Abstract

Energy levels, radiative rates, collision strengths, and effective collision strengths for all transitions up to and including the  levels of Al XIII have been computed in the jj coupling scheme including relativistic effects. All partial waves with angular momentum have been included, and resonances have been resolved in a fine energy grid in the threshold region. Collision strengths are tabulated at energies above thresholds in the range  Ryd, and results for effective collision strengths, obtained after integrating the collision strengths over a Maxwellian distribution of electron velocities, are tabulated over a wide temperature range of  K. The importance of including relativistic effects in a calculation is discussed in comparison with the earlier available non-relativistic results.