J/ApJ/767/47 Fe13+, Fe16+, Fe17+ cross-section measurements (Hahn+, 2013)
Storage ring cross section measurements for electron impact single and double
ionization of Fe13+ and single ionization of Fe16+ and Fe17+.
Hahn M., Becker A., Bernhardt D., Grieser M., Krantz C., Lestinsky M.,
Muller A., Novotny O., Repnow R., Schippers S., Spruck K., Wolf A.,
Savin D.W.
<Astrophys. J., 767, 47 (2013)>
=2013ApJ...767...47H 2013ApJ...767...47H
ADC_Keywords: Atomic physics
Keywords: atomic data; atomic processes; methods: laboratory
Abstract:
We report measurements of electron impact ionization for Fe13+,
Fe16+, and Fe17+ over collision energies from below threshold to
above 3000eV. 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
(1992ApJ...398..394A 1992ApJ...398..394A) is more than 30% larger, while that of Dere
(2007, J/A+A/466/771) 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.
Description:
Cross section measurements for Al-like Fe13+, Ne-like Fe16+, and
F-like Fe17+ were performed using the TSR heavy ion storage ring.
This facility is located at the Max-Planck-Institut fur Kernphysik in
Heidelberg, Germany.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 30 428 Fe13+ single ionization cross section
table3.dat 30 161 Fe16+ single ionization cross section
table4.dat 30 142 Fe17+ single ionization cross section
table6.dat 30 246 Fe13+ double ionization cross section
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See also:
J/ApJ/767/123 : FeXIV, FeXV and FeXVI transitions (Ferland+, 2013)
J/ApJ/760/80 : Fe9+ and Fe10+ cross-section measurements (Hahn+, 2012)
J/A+A/518/A64 : Na-like iso-electronic sequence. II. (Liang+, 2010)
J/A+A/466/771 : Ionization rate coefficients for elements H to Zn (Dere+, 2007)
J/A+A/459/307 : Fe XVIII Benchmarking atomic data (Del Zanna+, 2006)
J/A+AS/97/443 : Fluorescence for Be to Zn (Kaastra+ 1993)
Byte-by-byte Description of file: table[2346].dat
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Bytes Format Units Label Explanations
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1- 7 F7.2 eV E [315/3212] Collision energy
9- 19 E11.4 cm2 sigma Cross section
21- 30 E10.4 cm2 e_sigma Statistical uncertainty in sigma (1)
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Note (1): In addition, there is a systematic uncertainty of 16% in the
magnitude of the cross section (see the text).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 17-Nov-2014