Rmatrix electronimpact excitation data for the Belike isoelectronic sequence
Abstract
Aims: Emission lines from ions in the Belike isoelectronic sequence can be used for reliable diagnostics of temperature and density of astrophysical and fusion plasmas over a wide range of temperatures. Surprisingly, interpolated data is all that is available for a number of astrophysically important ions.
Methods: We have carried out intermediate coupling frame transformation Rmatrix calculations which include a total of 238 finestructure levels in both the configuration interaction target and closecoupling collision expansions. These arise from the configurations 1s^{2} 2 {s, p} nl with n = 37, and l = 04 for n ≤ 5 and l = 02 for n = 6,7.
Results: We obtain ordinary collision strengths and Maxwellaveraged effective collision strengths for the electronimpact excitation of all the ions of the Belike sequence, from B^{+} to Zn^{26+}. We compare with previous Rmatrix calculations and interpolated values for some benchmark ions. We find good agreement for transitions n = 22 with previous Rmatrix calculations but some disagreements with interpolated values. We also find good agreement for the most intense transitions n = 23 which contribute via cascade to the (n = 2) diagnostic radiating levels.
These data are made available in the archives of APAP via http://www.apapnetwork.org and OPENADAS via http://open.adas.ac.uk
 Publication:

Astronomy and Astrophysics
 Pub Date:
 June 2014
 DOI:
 10.1051/00046361/201423864
 Bibcode:
 2014A&A...566A.104F
 Keywords:

 atomic data;
 techniques: spectroscopic