COLLISION STRENGTHS AND RATE COEFFICIENTS FOR ELECTRON-IMPACT EXCITATION IN HE-I - AN EXTRAPOLATION OF R-MATRIX CALCULATIONS TO HIGHER ELECTRON-IMPACT ENERGIES

Citation
Ac. Lanzafame et al., COLLISION STRENGTHS AND RATE COEFFICIENTS FOR ELECTRON-IMPACT EXCITATION IN HE-I - AN EXTRAPOLATION OF R-MATRIX CALCULATIONS TO HIGHER ELECTRON-IMPACT ENERGIES, Monthly Notices of the Royal Astronomical Society, 264(2), 1993, pp. 402-410
Citations number
16
Categorie Soggetti
Astronomy & Astrophysics
ISSN journal
00358711
Volume
264
Issue
2
Year of publication
1993
Pages
402 - 410
Database
ISI
SICI code
0035-8711(1993)264:2<402:CSARCF>2.0.ZU;2-Z
Abstract
Extrapolations to higher electron impact energies of collision strengt hs calculated using the R-matrix method are presented for electric dip ole allowed transitions of neutral helium. The extrapolations are base d on a spline fit constrained by the high-energy limiting behaviour de duced from the Bethe approximation. This fit allows the calculation of the rate coefficients over a wide temperature range. The possibility of calculating collision rates in a non-equilibrium plasma is also dis cussed.