Observations of giant recombination edges on the Princeton Large Torus tokamak induced by particle transport

Journal Article · Mon Dec 01 04:00:00 EST 1980 · Phys. Rev., A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.22.2769· OSTI ID:7050915

Brau, K; von Goeler, S; Bitter, M; Cowan, R D; Eames, D; Hill, K; Sauthoff, N; Silver, E; Stodiek, W

In this paper we report on the observation of characteristic ''steps'' in the continuum spectrum of high-temperature tokamak plasmas associated with recombination radiation from impurity ions. During special argon-seeded discharges on the Princeton Large Torus tokamak the x-ray spectrum exhibited large enhancements over the bremsstrahlung continuum beginning with energies of 4.1 keV. This corresponds to the radiative capture of free electrons by hydrogenlike argon into the ground state of heliumlike argon. The size of these edges increased to unexpectedly large values with minor radius (decreasing electron temperature), consistent with a departure of the hydrogenlike species from the predictions of corona equilibrium. Hence, the coronal equilibrium equations must be modified to account for the radial transport of argon. A simple particle diffusion model is proposed, with the Ar XVIII radial profiles evaluated from the size of the recombination edges. For the case of moderate density (approx.3 x 10/sup 13/ cm/sup -3/) and temperature (T/sub e/(0)approx.1.5 keV) discharges the outward radial transport velocity is found to be approximately 10 m/sec.

• Research Organization: Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08544
• OSTI ID: 7050915
• Journal Information: Phys. Rev., A; (United States), Journal Name: Phys. Rev., A; (United States) Vol. 22:6; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700104* -- Fusion Energy-- Plasma Research-- Plasma Kinetics-Experimental-- (-1987)
ARGON
CAPTURE
DATA
ELECTRON CAPTURE
ELEMENTS
EXPERIMENTAL DATA
FLUIDS
GASES
IMPURITIES
INFORMATION
NONMETALS
NUMERICAL DATA
PLT DEVICES
RARE GASES
RECOMBINATION
SPECTRA
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS
X-RAY SPECTRA