Details

Autor(en) / Beteiligte

• Brown, G V
• Beiersdorfer, P
• Chen, H
• Scofield, J H
• Boyce, K R
• Kelley, R L
• Kilbourne, C A
• Porter, F S
• Kahn, S M
• Szymkowiak, A E

Titel

Energy-dependent excitation cross section measurements of the diagnostic lines of Fe XVII

Ist Teil von

• Physical review letters, 2005-01, Vol.96

Ort / Verlag

United States

Erscheinungsjahr

2005

Quelle

APS_美国物理学会过刊

Beschreibungen/Notizen

• By implementing a large-area, gain-stabilized microcalorimeter array on an electron beam ion trap, the electron-impact excitation cross sections for the dominant x-ray lines in the Fe XVII spectrum have been measured as a function of electron energy up to greater than three times the threshold energy, establishing a benchmark for atomic calculations. The results reveal a consistent overestimation by recent calculations of the excitation cross section of the resonance transition, which is shown to be at the root of several long-standing problems associated with modeling solar and astrophysical Fe XVII spectra. The data do not show strong contributions from resonance excitation contrary to recent statements in the literature.