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High-resolution measurements, line identification, and spectral modeling of K-alpha transitions in Fe XVIII-Fe XXVA detailed analysis of the iron K-alpha emission spectrum covering the wavelength region from 1.840 to 1.940 A is presented. Measurements are made with a high-resolution Bragg crystal spectrometer on the Princeton Large Torus (PLT) tokamak for plasma conditions which closely resemble those of solar flares. A total of 40 features are identified, consisting of either single or multiple lines from eight charge states in iron, Fe XVIII - Fe XXV, and their wavelengths are determined with an accuracy of 0.1-0.4 mA. Many of these features are identified for the first time. In the interpretation of our observations we rely on model calculations that determine the ionic species abundances from electron density and temperature profiles measured independently with nonspectroscopic techniques and that incorporate theoretical collisional excitation and dielectronic recombination rates resulting in the excitation of the 1s2sr2ps configurations. The model calculations also include the effect of diffusive ion transport. Good overall agreement between the model calculations and the observations is obtained, which gives us confidence in our line identifications and spectral modeling capabilities. The results are compared with earlier analyses of the K-alpha emission from the Sun.
Document ID
19930053813
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Beiersdorfer, P.
(NASA Headquarters Washington, DC United States)
Phillips, T.
(Lawrence Livermore National Lab. Livermore, CA, United States)
Jacobs, V. L.
(U.S. Navy, Naval Research Lab. Washington, United States)
Hill, K. W.
(NASA Headquarters Washington, DC United States)
Bitter, M.
(NASA Headquarters Washington, DC United States)
Von Goeler, S.
(Princeton Univ. NJ, United States)
Kahn, S. M.
(California Univ. Berkeley, United States)
Date Acquired
August 16, 2013
Publication Date
June 1, 1993
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 409
Issue: 2
ISSN: 0004-637X
Subject Category
Plasma Physics
Accession Number
93A37810
Funding Number(s)
CONTRACT_GRANT: NAGW-2688
CONTRACT_GRANT: DE-AC02-76CH-03073
CONTRACT_GRANT: W-7405-ENG-48
Distribution Limits
Public
Copyright
Other

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