Effective collision strengths for allowed transitions among the n 
5 degenerate levels of Al XIII
1
Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, UK e-mail: K.Aggarwal@qub.ac.uk
2
Department of Applied Physics, Faculty of Engineering, University of Miyazaki, Miyazaki 889-2192, Japan
Received:
26
October
2007
Accepted:
17
December
2007
Aims.In this paper we report on calculations of collision strengths and effective collision strengths for allowed transitions among the 
5 degenerate levels of Al xiii.
Methods.The Dirac atomic R-matrix code (darc) has been adopted for these calculations.
Results.Collision strengths are reported over a wide energy range below 300 Ryd, and effective collision strengths are provided for electron temperatures of 4.4 ≤ log 
6.8 K.
Key words: atomic data / atomic processes
© ESO, 2008