Atomic data from the IRON Project. XXXII. On the accuracy of the effective collision strength for the electron impact excitation of the quadrupole transition in AR III

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

11

Atomic And Molecular Data

Scientific paper

Since te[Burgess et al. (1997)]{bur97} have recently questioned the accuracy of the effective collision strength calculated in the IRON Project for the electron impact excitation of the 3ssp23p sp4 \ sp1 D -sp1 S quadrupole transition in Ar iii, an extended R-matrix calculation has been performed for this transition. The original 24-state target model was maintained, but the energy regime was increased to 100 Ryd. It is shown that in order to ensure convergence of the partial wave expansion at such energies, it is necessary to take into account partial collision strengths up to L=30 and to ``top-up'' with a geometric series procedure. By comparing effective collision strengths, it is found that the differences from the original calculation are not greater than 25% around the upper end of the common temperature range and that they are much smaller than 20% over most of it. This is consistent with the accuracy rating (20%) previously assigned to transitions in this low ionisation system. Also the present high-temperature limit agrees fairly well (15%) with the Coulomb-Born limit estimated by Burgess et al., thus confirming our previous accuracy rating. It appears that Burgess et al., in their data assessment, have overextended the low-energy behaviour of our reduced effective collision strength to obtain an extrapolated high-temperature limit that appeared to be in error by a factor of 2.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Atomic data from the IRON Project. XXXII. On the accuracy of the effective collision strength for the electron impact excitation of the quadrupole transition in AR III does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Atomic data from the IRON Project. XXXII. On the accuracy of the effective collision strength for the electron impact excitation of the quadrupole transition in AR III, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Atomic data from the IRON Project. XXXII. On the accuracy of the effective collision strength for the electron impact excitation of the quadrupole transition in AR III will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-992016

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.