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Storage Ring Cross Section Measurements for Electron Impact Ionization of Fe7+

Michael Hahn; A. Becker; D. Bernhardt; M. Grieser; C. Krantz; M. Lestinsky; A. Muller; Oldrich Novotny; R. Repnow; S. Schippers; K. Spruck; A. Wolf; Daniel Wolf Savin

Title:
Storage Ring Cross Section Measurements for Electron Impact Ionization of Fe7+
Author(s):
Hahn, Michael
Becker, A.
Bernhardt, D.
Grieser, M.
Krantz, C.
Lestinsky, M.
Muller, A.
Novotny, Oldrich
Repnow, R.
Schippers, S.
Spruck, K.
Wolf, A.
Savin, Daniel Wolf
Date:
Type:
Articles
Department(s):
Astrophysics Laboratory
Volume:
814
Persistent URL:
Book/Journal Title:
The Astrophysical Journal
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.
Subject(s):
Storage rings
Electron impact ionization
Astrophysics
Publisher DOI:
https://doi.org/10.1088/0004-637X/813/1/16
Item views
23
Metadata:
text | xml
Suggested Citation:
Michael Hahn, A. Becker, D. Bernhardt, M. Grieser, C. Krantz, M. Lestinsky, A. Muller, Oldrich Novotny, R. Repnow, S. Schippers, K. Spruck, A. Wolf, Daniel Wolf Savin, , Storage Ring Cross Section Measurements for Electron Impact Ionization of Fe7+, Columbia University Academic Commons, .

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