Comparison of the C III, O V, F VI, and Ne VII Delta n = 0 (2-2) line emissions from a laboratory plasma with theoretical predictions and astrophysical observations
Spectra of the Delta n = 0 (2-2) transitions of Be I-like ions, C III, O V, F VI, and Ne VII emitted from the TEXT tokamak, were measured with photometrically calibrated instrumentation and compared to the predictions of several models which differ in their treatment of electron impact excitation, using either the distorted wave or R-matrix approach. It was found that the ions from C III to Ne VII were located near the edge of the plasma, at densities between 10 to the 12th and 13th/cu cm. The experimental line ratios were compared with several sets of computations. Agreement is obtained between the experimental data and computations by using the R-matrix technique. This leads to the conclusion that the effect resonances must be included in collision strength calculations, particularly at low nuclear charge. The results show that the line ratios studied may be used with confidence as electron density diagnostics for laboratory or astrophysical plasmas. 34 references.
- Research Organization:
- Johns Hopkins Univ., Baltimore, MD; NASA, Goddard Space Flight Center, Greenbelt, MD
- OSTI ID:
- 6469432
- Journal Information:
- Astrophys. J.; (United States), Vol. 313
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ASTROPHYSICS
PLASMA DIAGNOSTICS
PLASMA
ELECTRON DENSITY
CARBON
ENERGY-LEVEL TRANSITIONS
FLUORINE
NEON
OXYGEN IONS
SPECTROSCOPY
TOKAMAK DEVICES
CHARGED PARTICLES
CLOSED PLASMA DEVICES
ELEMENTS
FLUIDS
GASES
HALOGENS
IONS
NONMETALS
RARE GASES
THERMONUCLEAR DEVICES
640100* - Astrophysics & Cosmology
700102 - Fusion Energy- Plasma Research- Diagnostics