Resonance enhanced electron impact excitation for P-like Cu XV**Project supported by the National Natural Science Foundation of China (Grant Nos. 11076009 and 11374062), the Chinese Association of Atomic and Molecular Data, the Chinese National Fusion Project for ITER (Grant No. 2015GB117000), and the Leading Academic Discipline Project of Shanghai, China (Grant No. B107).

Abstract

Employing both the Dirac R-matrix and the relativistic distorted wave with independent process and isolated resonance approaches, we report resonance enhanced electron impact excitation data (specifically, effective collision strengths) among the lowest 41 levels from the n = 3 configurations of Cu XV. The results show that the latter approach can obtain resonance contributions reasonably well for most excitations of Cu XV, though a comparison between the two approaches shows that the close-coupling effects are truly significant for rather weak excitations, especially for two-electron excitations from the 3s3p4 to 3s23p23d configuration. Resonance contributions are significant (more than two orders of magnitude) for many excitations and dramatically influence the line intensity ratios associated with density diagnostics.