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Measurement of Stark width of some Ar I transitions and the investigation of local thermodynamic equilibrium (LTE) in an atmospheric d. c. argon plasma jet

Thesis/Dissertation ·
OSTI ID:7057904
The Stark widths of seven Ar I transitions are reported. Axial line shape data from an atmospheric d.c. argon plasma jet were Abel-inverted to obtain radial line shapes. The electron-density was determined by Stark width measurements of the hydrogen H{sub {beta}} transition. In the electron-density region of {le}6 {times} 10{sup 22} m{sup {minus}3} the experimental Ar I Stark widths are fitted to a linear dependence on the electron-density. Values of Stark width extrapolated to other electron densities are compared to measurements reported in the literature on the 4s-4p array. Experimental values are up to 45% smaller than those predicted by Griem's theory of Stark broadening. Conditions for local thermodynamic equilibrium (LTE) to exist in an atmospheric argon plasma jet were studied. The experiment measures the emission coefficient of seven Ar I transitions and the line shape of the hydrogen H{sub beta} transition. After transforming the side-on data into radial space the excited neutral argon atom-density and the electron-density are determined. It is found LTE does not exist below an electron-density of 6 {times} 10{sup 33} m{sup {minus}3} in the experimental conditions.
Research Organization:
Idaho Univ., Moscow, ID (USA)
OSTI ID:
7057904
Country of Publication:
United States
Language:
English