Effective collision strengths for fine-structure forbidden transitions among the 2s22p3 levels of Ne IV


Autoria(s): Ramsbottom, C. A.; Bell, K. L.; Keenan, F. P.
Data(s)

21/01/1998

Resumo

<p>Effective collision strengths for electron-impact excitation of the N-like ion NeIV are calculated in the close-coupling approximation using the multichannel R-matrix method. Specific attention is given to the 10 astrophysically important fine-structure forbidden transitions among the <sup>4</sup>S<sup>o</sup>, <sup>2</sup>D<sup>o</sup> and <sup>2</sup>P<sup>o</sup> levels in the 2s<sup>2</sup>2p<sup>3</sup> ground-state configuration. The expansion of the total wavefunction incorporates the lowest 11 LS eigenstates of NeIV, consisting of eight n = 2 terms with configurations 2s<sup>2</sup>2p<sup>3</sup>, 2s2p<sup>4</sup> and 2p<sup>5</sup>, together with three n = 3 states of configuration 2s<sup>2</sup>2p<sup>2</sup>3s. We present in graphical form the effective collision strengths obtained by thermally averaging the collision strengths over a Maxwellian distribution of velocities, for all 10 fine-structure transitions, over the range of electron temperatures log T(K) = 3.6 to log T(K) = 6.1 (the range appropriate for astrophysical applications). Comparisons are made with the earlier, less sophisticated close-coupling calculation of Giles, and excellent agreement is found in the limited temperature region where a comparison is possible [log T(K) = 3.7 to log 7(K) = 4.3]. At higher temperatures the present data are the only reliable results currently available.</p>

Identificador

http://pure.qub.ac.uk/portal/en/publications/effective-collision-strengths-for-finestructure-forbidden-transitions-among-the-2s22p3-levels-of-ne-iv(91587791-6562-4600-8ebd-6f55a78b8cc8).html

http://www.scopus.com/inward/record.url?scp=0000899344&partnerID=8YFLogxK

Idioma(s)

eng

Direitos

info:eu-repo/semantics/restrictedAccess

Fonte

Ramsbottom , C A , Bell , K L & Keenan , F P 1998 , ' Effective collision strengths for fine-structure forbidden transitions among the 2s22p3 levels of Ne IV ' Monthly Notices of the Royal Astronomical Society , vol 293 , no. 3 , pp. 233-238 .

Palavras-Chave #Atomic processes #Line: Formation #/dk/atira/pure/subjectarea/asjc/1900/1912 #Space and Planetary Science
Tipo

article