Atomic data from the IRON Project. XXIII. Relativistic excitation rate coefficients for Fe XXII with inclusion of radiation damping
Abstract
New collision strengths have been calculated for 990 transitions among 45 fine structure n=2 and n=3 levels of Fe XXII. The relativistic BreitPauli formulation of the Rmatrix method was employed in the close coupling approximation, with radiation damping of autoionizing resonances included for the first time in the calculations of excitation rate coefficients. It is found that, at low temperatures, the relativistic effects considerably enhance rate coefficients for the intercombination transitions, and the radiation damping effect reduces those for a few transitions. It is also found that resonances due to coupling with the n=3 levels significantly enhance rate coefficients for the transitions to lowlying levels at intermediate and high temperatures, and for the transitions to the n=2 highlying levels at all temperatures. It is expected that the new data, tabulated at a wide range of temperatures, would lead to a revision of the spectral diagnostics of Fe XXII in laboratory and astrophysical sources, in particular the Xray spectra observed from solar flares and tokamaks. Table 3, 4 and 5 for complete data for Fe XXII are only available in electronic form at the CDS via anonymous ftp to cdsarc.ustrasbg.fr (130.79.128.5) or via http://cdsweb.ustrasbg.fr/Abstract.html
 Publication:

Astronomy and Astrophysics Supplement Series
 Pub Date:
 June 1997
 DOI:
 10.1051/aas:1997352
 Bibcode:
 1997A&AS..123..575Z
 Keywords:

 ATOMIC DATA;
 SUN: FLARES;
 XRAYS: GENERAL