Measurement of electron collisional excitation rate coefficients for FeX

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1982

OSTI ID:5869353

Wang, J S

Electron collisional excitation rate coefficients were obtained for FeX using a high temperature theta-pinch plasma. Iron atoms were introduced into the plasma by applying a small plasma gun with iron electrodes. The absolute intensities of FeX vacuum-ultraviolet lines were measured using a 2.2m grazing incidence monochromator which was calibrated by the branching ratio technique. The FeX density was determined by measuring the intensity of a forbidden transition at 6374.5A from /sup 2/P/sub (1/2)/ to /sup 2/P/sub (3/2)/ of the FeX ground configuration, assuming populations of the two levels to be in local thermal equilibrium. Electron temperatures and densities were measured by Thomson scattering. Measurements were made for three plasma conditions, and excitation rate coefficients at electron temperatures 95 eV, 45 eV, and 75 eV were obtained absolutely. The maximum error of the experimental rate coefficients was estiamted to be 30% for the first two conditions, and 40% for the third one. The rate coefficients are compared with available theoretical calculations. For the transitions 3p/sup 5/ to 3p/sup 4/3d, the experimental results are in good agreement with theoretical values. For the transitions 3p/sup 5/ to 4p/sup 4/4s, the measured rate coefficients are higher by a factor of 2 to 4. This discrepancy may be explained by the effect of cascading from higher excited states.

• Research Organization: Maryland Univ., College Park (USA)
• OSTI ID: 5869353
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700102 -- Fusion Energy-- Plasma Research-- Diagnostics
700104* -- Fusion Energy-- Plasma Research-- Plasma Kinetics-Experimental-- (-1987)
ATOMS
COLLISIONS
ELECTRON COLLISIONS
ELECTRON DENSITY
ELECTRON TEMPERATURE
ELEMENTS
ENERGY-LEVEL TRANSITIONS
EXCITATION
HOT PLASMA
INELASTIC SCATTERING
IRON
METALS
PINCH EFFECT
PLASMA
SCATTERING
SPECTRA
THETA PINCH
THOMSON SCATTERING
TRANSITION ELEMENTS
ULTRAVIOLET SPECTRA