Spectral study of adiabatic plasma compression in a tokamak

Journal Article · Sun May 01 04:00:00 EDT 1977 · Sov. J. Plasma Phys. (Engl. Transl.); (United States)

OSTI ID:5233532

Kaganskii, M G; Kalmykov, S G; Lebedev, S V; Shakhovets, K G

The line emission of impurity ions in the visible and UV regions has been studied. The spatial distribution of the emission intensity yields the radial profile of the electron temperature in the ohmic-heating regime, which precedes the magnetic compression of the plasma. The temperature profile is constructed with the help of experimental results on Thomson scattering of a laser beam. The profile T/sub e/(r) in the compressed plasma is determined from the time evolution of the intensities of the spectral lines. This profile is substantially asymmetric, because of an outward displacement of the inner magnetic surfaces as the result of an increase in ..beta../sub j/. Calculations on the basis of the plasma properties show that ..beta../sub j/ increases from 0.6 to 2.0--2.5 in the course of the compression. The maximum electron temperature in the compressed plasma is approx.400 eV, which is higher by a factor or 1.7 than that calculated under the assumption of purely adiabatic heating. The implication is an improvement in the thermal insulation of the plasma. The energy lifetime increases from 150 ..mu..sec in the case of ohmic heating to 800 ..mu..sec in the compressed plasma. The time evolution of the radial profile of the intensity of the O V line confirms the efficiency of the heating of the plasma by the magnetic field. The plasma density increases by a factor of three during the compression, in accordance with the adiabatic law.

• Research Organization: A. F. Ioffe Physicotechnical Institute, Academy of Sciences of the USSR, Leningrad
• OSTI ID: 5233532
• Journal Information: Sov. J. Plasma Phys. (Engl. Transl.); (United States), Journal Name: Sov. J. Plasma Phys. (Engl. Transl.); (United States) Vol. 3:3; ISSN SJPPD
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
ADIABATIC COMPRESSION HEATING
CLOSED PLASMA DEVICES
HEATING
IMPURITIES
PHYSICAL PROPERTIES
PLASMA HEATING
SPECTRA
THERMAL CONDUCTIVITY
THERMAL INSULATION
THERMODYNAMIC PROPERTIES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TUMAN DEVICES
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA