Abstract
We report calculations of collision strengths and effective collision strengths for 26 allowed transitions among the n≤ 5 degenerate levels of atomic hydrogen for which the close-coupling (CC) and Born approximations have been used. Results are listed over a wide range of energies (up to 100 Ryd) and temperatures (up to 107 K), sufficient for applications over a variety of plasmas, including fusion. Similar results have also been calculated for deuterium, but they negligibly differ with those of hydrogen.
Highlights
Hydrogen is the most abundant element in the universe and, atomic data for its emission lines are very important for various studies of astrophysical plasmas
The calculations were based on the close-coupling R-matrix method and reported results for both collision strengths (Ω) and effective collision strengths (Υ), obtained after integrating the Ω data over a Maxwellian distribution of electron velocities—see a review by Henry [6]
Practically the only reliable Υ data available for a larger number of transitions are those of Aggarwal et al Irrespective of theaccuracy of these data, a major deficiency in the literature is that results for fine structure transitions, which are allowed among the degenerate levels of states, such as 3p 2 P1/2,3/2 –3d 2 D3/2,5/2 and 4d 2 D3/2,5/2 –4f 2 F5/2,7/2, are not yet available
Summary
Hydrogen is the most abundant element in the universe and, atomic data for its emission lines are very important for various studies of astrophysical plasmas. They presented their results for Ω only graphically, corresponding numerical data can be obtained, in a very fine energy mesh, from their website http://utf.mff.cuni.cz/data/hex They did not report the corresponding data for Υ, which are required for the modelling or diagnostics of the plasmas, and neither can be calculated from their numerical data (except at very low temperatures), because of the limited energy range, below 1 Ryd. practically the only reliable Υ data available for a larger number of transitions are those of Aggarwal et al Irrespective of the (in)accuracy of these (or other available) data, a major deficiency in the literature is that results for fine structure transitions, which are allowed among the degenerate levels of states, such as 3p 2 P1/2,3/2 –3d 2 D3/2,5/2 and 4d 2 D3/2,5/2 –4f 2 F5/2,7/2 , are not yet available. We perform calculations for deuterium (D) because it is part of fusion fuel
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