Electron-impact excitation rates of Na-like ions

¹ Department of Materials Science, Faculty of Engineering, Miyazaki University, Miyazaki 889-2192, Japan
² Institute of Space and Astronautical Science, Yoshinodai, Sagamihara 229-8510, Japan

Send offprint request to: S. Nakazaki

Received: 20 January 1998
Accepted: 30 March 1998

Abstract

Electron excitation collision strengths for all the transitions among 3s, 3p, 3d, 4s, 4p, 4d, 4f states of the five Na-like ions Al III, Si IV, S VI, Ar VIII and Ca X are calculated in the R-matrix approximation. Eleven target terms are included in the expansion of the total wavefunction. These collision strengths are averaged over a Maxwellian velocity distribution to obtain effective collision strengths as a function of electron temperature. The resulting values are compared with the results of previous less elaborate calculations to find some disagreements.