Journal article

Publication year: 2015

Journal: The Astrophysical Journal

Volume number: 813

Issue number: 1

ISSN: 0004-637X

eISSN: 1538-4357

Open access status: Green

DOI Link: https://doi.org/10.1088/0004-637X/813/1/16

Publisher: American Astronomical Society

Abstract: 
We have measured electron impact ionization for Fe7+ from the ionization threshold up to 1200 eV. The measurements were performed using the TSR heavy ion storage ring. The ions were stored long enough prior to measurements to remove most metastables, resulting in a beam of 94% ground-level ions. Comparing with the previously recommended atomic data, we find that the Arnaud & Raymond cross section is up to about 40% larger than our measurement, with the largest discrepancies below about 400 eV. The cross section of Dere agrees to within 10%, which is about the magnitude of the experimental uncertainties. The remaining discrepancies between our measurement and the Dere calculations are likely due to shortcomings in the theoretical treatment of the excitation-autoionization contribution.

Harvard Citation style: Hahn, M., Becker, A., Bernhardt, D., Grieser, M., Krantz, C., Lestinsky, M., et al. (2015) Storage Ring Cross Section Measurements For Electron Impact Ionization of Fe7+, The Astrophysical Journal, 813(1), Article 16. https://doi.org/10.1088/0004-637X/813/1/16

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. (2015). Storage Ring Cross Section Measurements For Electron Impact Ionization of Fe7+. The Astrophysical Journal. 813(1), Article 16. https://doi.org/10.1088/0004-637X/813/1/16