g-bar collision strengths for Rydberg levels (trac #365)

reported by: @CloudyLex

Title:  
Scaling of collision strengths for highly-excited states of ions of the H- and He-like sequences
Authors:    
Fernández-Menchero, L.; Del Zanna, G.; Badnell, N. R.
Affiliation:    
AA(Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK luis.fernandez-menchero@drake.edu; Present address: Department of Physics and Astronomy, Drake University, 2507 University Avenue Des Moines, IA 50311, USA), AB(Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, CB3 0WA, UK), AC(Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK)
Publication:    
Astronomy & Astrophysics, Volume 592, id.A135, 9 pp. (A&A Homepage)
Publication Date:   
08/2016
Origin: 
EDP Sciences
Astronomy Keywords: 
atomic data, Sun: corona, techniques: spectroscopic
DOI:    
10.1051/0004-6361/201628484
Bibliographic Code: 
2016A&A...592A.135F
Abstract

Emission lines from highly-excited states (n ? 5) of H- and He-like ions have been 
detected in astrophysical sources and fusion plasmas. For such excited states, R-
matrix or distorted wave calculations for electron-impact excitation are very 
limited, due to the large size of the atomic basis set needed to describe them. 
Calculations for n ? 6 are also not generally available. We study the behaviour of 
the electron-impact excitation collision strengths and effective collision strengths 
for the most important transitions used to model electron collision dominated 
astrophysical plasmas, solar, for example. We investigate the dependence on the 
relevant parameters: the principal quantum number n or the nuclear charge Z. We 
also estimate the importance of coupling to highly-excited states and the 
continuum by comparing the results of different sized calculations. We provide 
analytic formulae to calculate the electron-impact excitation collision strengths 
and effective collision strengths to highly-excited states (n ? 8) of H- and He-like 
ions. These extrapolated effective collision strengths can be used to interpret 
astrophysical and fusion plasma via collisional-radiative modelling.

Tables of atomic data for Si xiii and S xv are only available at the CDS via 
anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via 
http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/592/A135

Migrated from https://www.nublado.org/ticket/365

{
    "status": "new",
    "changetime": "2019-02-04T13:02:49Z",
    "_ts": "1549285369825011",
    "description": "{{{\nTitle:\t\nScaling of collision strengths for highly-excited states of ions of the H- and He-like sequences\nAuthors:\t\nFern\u00e1ndez-Menchero, L.; Del Zanna, G.; Badnell, N. R.\nAffiliation:\t\nAA(Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK luis.fernandez-menchero@drake.edu; Present address: Department of Physics and Astronomy, Drake University, 2507 University Avenue Des Moines, IA 50311, USA), AB(Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, CB3 0WA, UK), AC(Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK)\nPublication:\t\nAstronomy & Astrophysics, Volume 592, id.A135, 9 pp. (A&A Homepage)\nPublication Date:\t\n08/2016\nOrigin:\t\nEDP Sciences\nAstronomy Keywords:\t\natomic data, Sun: corona, techniques: spectroscopic\nDOI:\t\n10.1051/0004-6361/201628484\nBibliographic Code:\t\n2016A&A...592A.135F\nAbstract\n\nEmission lines from highly-excited states (n ? 5) of H- and He-like ions have been \ndetected in astrophysical sources and fusion plasmas. For such excited states, R-\nmatrix or distorted wave calculations for electron-impact excitation are very \nlimited, due to the large size of the atomic basis set needed to describe them. \nCalculations for n ? 6 are also not generally available. We study the behaviour of \nthe electron-impact excitation collision strengths and effective collision strengths \nfor the most important transitions used to model electron collision dominated \nastrophysical plasmas, solar, for example. We investigate the dependence on the \nrelevant parameters: the principal quantum number n or the nuclear charge Z. We \nalso estimate the importance of coupling to highly-excited states and the \ncontinuum by comparing the results of different sized calculations. We provide \nanalytic formulae to calculate the electron-impact excitation collision strengths \nand effective collision strengths to highly-excited states (n ? 8) of H- and He-like \nions. These extrapolated effective collision strengths can be used to interpret \nastrophysical and fusion plasma via collisional-radiative modelling.\n\nTables of atomic data for Si xiii and S xv are only available at the CDS via \nanonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via \nhttp://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/592/A135\n}}}",
    "reporter": "gary",
    "cc": "",
    "resolution": "",
    "time": "2016-08-26T22:02:48Z",
    "component": "atomic/molecular data base",
    "summary": "g-bar collision strengths for Rydberg levels",
    "priority": "good to do",
    "keywords": "",
    "version": "trunk",
    "milestone": "no milestone",
    "owner": "nobody",
    "type": "enhancement"
}

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g-bar collision strengths for Rydberg levels (trac #365) #367