Dirac R -matrix method for the calculation of x-ray line polarization
Abstract
We have developed a method within the Dirac R -matrix theory to calculate x-ray line polarization resulting from electron-impact excitation to excited-state magnetic sublevels of complex ions. We apply this method to the excitation of two well-known x-ray lines of Fe XVII, 3C (λ=15.015Å) and 3D (λ=15.262Å) . We find strong resonance effects which contribute to complicated energy dependence in the polarization. Our results show large differences, up to 30% or more, from earlier theoretical work, and thus provide a stimulus for direct experimental measurement of the 3C and 3D line polarizations and further theoretical studies.
- Publication:
-
Physical Review A
- Pub Date:
- June 2009
- DOI:
- 10.1103/PhysRevA.79.062715
- Bibcode:
- 2009PhRvA..79f2715C
- Keywords:
-
- 34.80.Dp;
- 32.30.Rj;
- 34.80.Nz;
- Atomic excitation and ionization by electron impact;
- X-ray spectra;
- Spin dependence of cross sections;
- polarized electron beam experiments