Opened 4 years ago

#290 new enhancement

atomic data for Be seq

Reported by: Gary J. Ferland Owned by: nobody
Priority: good to do Milestone:
Component: atomic/molecular data base Version: trunk
Keywords: Cc:


R-matrix electron-impact excitation data for the Be-like iso-electronic sequence
Fernández-Menchero, L.; Del Zanna, G.; Badnell, N. R.
AA(Department of PhysicsUniversity of Strathclyde, Glasgow, G4 0NG, UK ), AB(Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, CB3 0WA, UK), AC(Department of PhysicsUniversity of Strathclyde, Glasgow, G4 0NG, UK )
Astronomy & Astrophysics, Volume 566, id.A104, 11 pp. (A&A Homepage)
Publication Date:	
EDP Sciences
Astronomy Keywords:	
atomic data, techniques: spectroscopic
Bibliographic Code:	

Aims: Emission lines from ions in the Be-like 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 R-matrix 
calculations which include a total of 238 fine-structure levels in both the configuration 
interaction target and close-coupling collision expansions. These arise from the 
configurations 1s2 2 {s, p} nl with n = 3-7, and l = 0-4 for n ? 5 and l = 0-2 for n = 6,7. 

Results: We obtain ordinary collision strengths and Maxwell-averaged effective collision 
strengths for the electron-impact excitation of all the ions of the Be-like sequence, from 
B+ to Zn26+. We compare with previous R-matrix calculations and interpolated values for 
some benchmark ions. We find good agreement for transitions n = 2-2 with previous R-
matrix calculations but some disagreements with interpolated values. We also find good 
agreement for the most intense transitions n = 2-3 which contribute via cascade to the (n 
= 2) diagnostic radiating levels.

These data are made available in the archives of APAP via 
and OPEN-ADAS via

GJF: Collision rates for some C III lines differ by 2x from previous work.

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