Rmatrix electronimpact excitation data for the Mglike isoelectronic sequence
Abstract
Aims: Emission lines from ions in the Mglike isoelectronic sequence can be used as reliable diagnostics of temperature and density of astrophysical and fusion plasmas over a wide range of parameters. Data in the literature are quite lacking, there are no calculations for many of the ions in the sequence.
Methods: We have carriedout intermediate coupling frame transformation Rmatrix calculations which include a total of 283 finestructure levels in both the configuration interaction target and closecoupling collision expansions. These arise from the configurations 1s^{2} 2s^{2} 2p^{6} 3 {s,p,d} nl with n = 4,5, and for l = 04.
Results: We obtain ordinary collision strengths and Maxwellaveraged effective collision strengths for the electronimpact excitation of all the ions of the Mglike sequence, from Al^{+} to Zn^{18 +}. We compare our results with those from previous Rmatrix and distorted waves calculations, where available, for some benchmark ions. We find good agreement with the results of previous calculations for the transitions n = 33. We also find good agreement for the most intense transitions n = 34. These transitions are important for populating the upper levels of the main diagnostic lines.
These data are made available in the APAP archive via http://www.apapnetwork.org, CHIANTI via http://www.chiantidatabase.org and openADAS via http://open.adas.ac.uk
 Publication:

Astronomy and Astrophysics
 Pub Date:
 December 2014
 DOI:
 10.1051/00046361/201424849
 Bibcode:
 2014A&A...572A.115F
 Keywords:

 atomic data;
 techniques: spectroscopic