Stark broadening of the hydrogen resonance line L/sub. beta. / in a dense equilibrium plasma

Journal Article · Wed Nov 01 04:00:00 EST 1978 · Phys. Rev., A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.18.2140· OSTI ID:6575306

Gruetzmacher, K; Wende, B

Profiles of L/sub ..beta../ emitted from small hydrogen additions in a dense argon plasma (n/sub e/ = 1, 2, and 3 x 10/sup 23/ m/sup -3/, T approx. = 10/sup 4/ K) were measured under controlled optical depth over wavelength separation ..delta..lambda from lambda/sub L/..beta.. of about eight times the half-halfwidth ..delta..lambda/sub 1/2/. Reabsorption in the boundary layers of the plasma, usually caused by hydrogen as well as argon atoms, was avoided. The Stark profiles P (..delta..lambda) obtained (uncertainty +- 4% for vertical-bar ..delta..lambdavertical-bar /..delta..lambda/sub 1/2/ < or = 4) were found to be for vertical-bar ..delta..lambda vertical-bar /..delta..lambda/sub 1/2/ > 0.6 in good agreement with calculations according to the ''unified'' theories (Vidal et al. and Seidel) and to the modified impact theories (Griem and Bacon). For vertical-bar ..delta..lambda vertical-bar /..delta..lambda/sub 1/2/ < 0.6 deviations remain, particularly in the line center, even when time ordering and ion dynamics (Seidel) are taken into account. These residual discrepancies indicate, in accordance with deviations recently found for L/sub b/, that broadening mechanisms which are not finally identified are efficacious. The experimental L/sub ..beta../ profiles exhibit an asymmetry behavior similar to that calculated by Bacon, yielding that the asymmetry is mainly caused by ion-field inhomogeneities. Using the scale of angular frequencies the change of sign of the asymmetry is found to be at ..delta omega../..delta omega../sub 1/2/ = 0.5, whereas it is predicted by Bacon at ..delta omega../..delta omega../sub 1/2/ = 1.2. The measurements indicate red shifts of the centers of the profiles of about 10/sup -2/..delta omega../sub 1/2/ ( approx. = 10/sup -3/ nm for n/sub e/ = 2 x 10/sup 23/ m/sup -3/).

• Research Organization: Physikalisch-Technische Bundesanstalt, Institut Berlin, Abbestrasse 2-12, D-1000 Berlin 10, Germany
• OSTI ID: 6575306
• Journal Information: Phys. Rev., A; (United States), Journal Name: Phys. Rev., A; (United States) Vol. 18:5; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700102* -- Fusion Energy-- Plasma Research-- Diagnostics
ARGON
ELEMENTS
EMISSION SPECTRA
EQUILIBRIUM PLASMA
LINE BROADENING
LYMAN LINES
NONMETALS
PLASMA
PLASMA DIAGNOSTICS
RARE GASES
SPECTRA
STARK EFFECT