EXTREME-ULTRAVIOLET SPECTROSCOPY OF Fe VI-Fe XV AND ITS DIAGNOSTIC APPLICATION FOR ELECTRON BEAM ION TRAP PLASMAS

Journal Article · Sun May 10 00:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/696/2/2275; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21300612

Liang, G Y; Baumann, T M; Lopez-Urrutia, J R. Crespo; Epp, S W; Tawara, H; Gonchar, A; Mokler, P H; Ullrich, J ^[1]

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1. Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)

Extreme-ultraviolet spectra of intermediately ionized iron ions (Fe VI-Fe XIV) in the wavelength range of 125.0-265.0 A have been measured at the Heidelberg electron beam ion trap. Emission spectra were recorded sequentially while varying the electron energy over the range of 75-544 eV in steps of 5 eV. The observed spectra clearly show the evolution of each ionic stage as a function of the electron energy, allowing to distinguish the emission lines from neighboring ion charge species and helping to disentangle possible line blends. The collisional-radiative modeling satisfactorily reproduces the measurement. A comparison with previous astrophysical observations (Sun) reveals that some weak emissions may originate from Fe VI and Fe VII, resulting in incorrect assignment of transition lines. The calculated polarization effects due to nonthermal (monoenergetic) electrons are found to be negligible for most of the emission lines at low-energy electron impact, except for a few lines whose polarization can be over 20%. By line ratio technique, the effective electron density in the trap was estimated to be 7.1{sup +2.4} {sub -3.0} x 10{sup 9}-3.4{sup +0.5} {sub -0.5} x 10{sup 10} cm{sup -3}, slightly depending on the ion charge state.

• OSTI ID: 21300612
• Journal Information: Astrophysical Journal, Vol. 696, Issue 2; Other Information: DOI: 10.1088/0004-637X/696/2/2275; Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
ASTROPHYSICS
CHARGE STATES
ELECTRON BEAMS
ELECTRON DENSITY
EMISSION SPECTRA
EV RANGE
EXTREME ULTRAVIOLET RADIATION
EXTREME ULTRAVIOLET SPECTRA
IRON IONS
POLARIZATION
SIMULATION
SPECTROSCOPY
SUN
TRAPS
WAVELENGTHS