Journal article

Publication year: 2013

Journal: The Astrophysical Journal

Volume number: 767

Issue number: 1

ISSN: 0004-637X

eISSN: 1538-4357

Open access status: Green

DOI Link: https://doi.org/10.1088/0004-637X/767/1/47

Publisher: American Astronomical Society

Abstract: 
We report measurements of electron impact ionization for Fe13+, Fe16+, and Fe17+ over collision energies from below threshold to above 3000 eV. The ions were recirculated using an ion storage ring. Data were collected after a sufficiently long time that essentially all the ions had relaxed radiatively to their ground state. For single ionization of Fe13+, we find that previous single pass experiments are more than 40% larger than our results. Compared to our work, the theoretical cross section recommended by Arnaud & Raymond is more than 30% larger, while that of Dere is about 20% greater. Much of the discrepancy with Dere is due to the theory overestimating the contribution of excitation-autoionization via n = 2 excitations. Double ionization of Fe13+ is dominated by direct ionization of an inner shell electron accompanied by autoionization of a second electron. Our results for single ionization of Fe16+ and Fe17+ agree with theoretical calculations to within the experimental uncertainties.

Harvard Citation style: Hahn, M., Becker, A., Bernhardt, D., Grieser, M., Krantz, C., Lestinsky, M., et al. (2013) Storage ring cross section measurements for electron impact single and double ionization of Fe13+ and single ionization of Fe16+ and Fe17+, The Astrophysical Journal, 767(1), Article 47. https://doi.org/10.1088/0004-637X/767/1/47

APA Citation style: Hahn, M., Becker, A., Bernhardt, D., Grieser, M., Krantz, C., Lestinsky, M., Müller, A., Novotny, O., Repnow, R., Schippers, S., Spruck, K., Wolf, A., & Savin, D. (2013). Storage ring cross section measurements for electron impact single and double ionization of Fe13+ and single ionization of Fe16+ and Fe17+. The Astrophysical Journal. 767(1), Article 47. https://doi.org/10.1088/0004-637X/767/1/47