Measurement of hydrogen n-. cap alpha. -line Stark profiles in a turbulent plasma

Journal Article · Mon Nov 01 04:00:00 EST 1976 · Phys. Rev., A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.14.1853· OSTI ID:7348676

Nee, T A; Griem, H R

Two hydrogen n-..cap alpha.. transitions, n = 13 ..-->.. 12 at lambda88.7 ..mu..m and n = 12 ..-->.. 11 at lambda69.0 ..mu..m, were observed in a large-diameter theta discharge at electron densities between 10/sup 14/ and 3 x 10/sup 14/ cm/sup -3/. Line profiles were measured with a Czerny-Turner infrared monochromator and a Ge:Ga photodetector at liquid-helium temperature. Both n-..cap alpha.. lines exhibit strong and symmetric satellite features, with intensities comparable to their parent lines and displacements close to the electron plasma frequency ..omega../sub p/. These satellites can be interpreted in terms plasmon-atom collisions if long-wavelength fluctuations in this turbulent plasma are enhanced by a factor of approximately-greater-than 10/sup 3/ above the thermal level at T/sub e/ approx. = 0.7 eV. As an independent estimate for the level of turbulence, the continuum emission in the regions corresponding to ..omega../sub p/ and 2..omega../sub p/ was measured, and found to be well above the level expected for a thermal plasma. Comparison with fluid theory, after radiative transfer corrections, shows satisfactory consistency with the n-..cap alpha.. satellite diagnostics. (AIP)

• Research Organization: Department of Physics and Astronomy, University of Maryland, College Park, Maryland 20742
• OSTI ID: 7348676
• Journal Information: Phys. Rev., A; (United States), Journal Name: Phys. Rev., A; (United States) Vol. 14:5; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700102* -- Fusion Energy-- Plasma Research-- Diagnostics
CRYOGENIC FLUIDS
ELEMENTS
FLUIDS
HYDROGEN
LINE BROADENING
NONMETALS
PLASMA
PLASMA DIAGNOSTICS
STARK EFFECT
TURBULENCE