Direkt zum Inhalt
  1. Publizieren |
  2. Suche |
  3. Browsen |
  4. Neuzugänge rss |
  5. Open Access |
  6. Rechtsfragen |
  7. EnglishCookie löschen - von nun an wird die Spracheinstellung Ihres Browsers verwendet.

High-precision soft X-ray transition measurements of neon-like mid-Z ions using ultra monochromatic synchrotron radiation

Kühn, Steffen

[thumbnail of phdthesis_steffen_kuehn.pdf]
Vorschau
PDF, Englisch
Download (47MB) | Nutzungsbedingungen

Zitieren von Dokumenten: Bitte verwenden Sie für Zitate nicht die URL in der Adresszeile Ihres Webbrowsers, sondern entweder die angegebene DOI, URN oder die persistente URL, deren langfristige Verfügbarkeit wir garantieren. [mehr ...]

Abstract

For more than 40 years, most astrophysical observations and laboratory studies of two key soft X-ray diagnostic 2p-3d transitions, 3C and 3D, in Fe XVII ions found oscillator-strength ratios f3C/ f3D disagreeing with theory. This discrepancy hampered the proposed plasma diagnostic utility based on the observed intensity ratios ever since. In previous laboratory measurements, the ratio was determined by scrutinizing the photon emission of an electron-impact excited plasma. First X-ray laser spectroscopy experiments at a free-electron laser (FEL) confirmed the discrepancy between experiments and theory independently of electron-excitation cross sections that could have falsified previous laboratory measurements. In this thesis, the 3C/3D oscillator-strength ratio was measured by resonantly exciting the transitions utilizing highly brilliant and monochromatic X-ray synchrotron light. Thereby, two proposed systematical effects that could have lowered the results of the FEL measurements were excluded. The final result f3C/ f3D = 3.51(7) of this work is in excellent agreement with the newest state-of-the-art theoretical predictions and appears to finally resolve the long-lasting conundrum. Additionally, for the first time, the individual natural linewidths of lines 3C and 3D, among others, were determined with an uncertainty of � 15%. The findings of this thesis now allow the observed intensity ratios of 3C and 3D to enable their usefulness in the diagnostics of astrophysical spectra.

Dokumententyp: Dissertation
Erstgutachter: Crespo López-Urrutia, apl. Prof. Dr. José Ramón
Ort der Veröffentlichung: Heidelberg
Tag der Prüfung: 21 Juli 2021
Erstellungsdatum: 02 Aug. 2021 13:26
Erscheinungsjahr: 2021
Institute/Einrichtungen: Fakultät für Physik und Astronomie > Dekanat der Fakultät für Physik und Astronomie
Zentrale und Sonstige Einrichtungen > Max-Planck-Institute allgemein > MPI fuer Kernphysik
DDC-Sachgruppe: 530 Physik
Leitlinien | Häufige Fragen | Kontakt | Impressum |
OA-LogoDINI-Zertifikat 2013Logo der Open-Archives-Initiative