Effective charge state in a tokamak with a graphite wall and a graphite limiter (TM-G)

Journal Article · Sat Nov 01 04:00:00 EST 1986 · Sov. J. Plasma Phys. (Engl. Transl.); (United States)

OSTI ID:6778690

Palov, Y D; Petrov, D P; Solntsev, A M; Stefanovskii, A M; Terebkov, A L; Shcherbak, A F

Several methods have been used to evaluate the effective ionization Z/sub eff/ in a tokamak with an all-graphite first wall and a graphite limiter (the TM-G). The injection of a small amount of carbon into the plasma during laser bombardment of the graphite wall was used to measure Z/sub eff/ in addition to conventional methods, based on the plasma conductivity and the bremsstrahlung intensity in the visible region. Since carbon is essentially the only impurity in the hydrogen plasma of the TM-G (the oxygen ion density is tens of time lower than the density of carbon ions; other impurities are not detected spectrally), the temporal and amplitude characteristics of the additional intensity of the CV line and the soft x-ray emission which appear as a result were used to calculate the densities of C/sup +5/ and C/sup +6/ ions at the discharge axis. These results were also used to calculate the ''excess factor'' for the intensity of the x-ray emission of the plasma. For discharges in which the electron temperature at the axis of the plasma column, T/sub e/(0), is below 900 eV, and for average plasma densities n-bar/sub e/ up to 7x10/sup 13/ cm/sup -3/, all of the methods yield effective plasma charge states less than 1.5.

• Research Organization: I. V. Kurchatov Institute of Atomic Energy, Moscow
• OSTI ID: 6778690
• Journal Information: Sov. J. Plasma Phys. (Engl. Transl.); (United States), Journal Name: Sov. J. Plasma Phys. (Engl. Transl.); (United States) Vol. 12:11; ISSN SJPPD
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
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ANNULAR SPACE
CARBON
CHARGE STATE
CLOSED PLASMA DEVICES
CONFIGURATION
ELECTROMAGNETIC RADIATION
ELEMENTAL MINERALS
ELEMENTS
GRAPHITE
IMPURITIES
INSTABILITY
IONIZATION
IONIZING RADIATIONS
LIMITERS
MINERALS
NONMETALS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
RADIATIONS
SPACE
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TOROIDAL CONFIGURATION
X RADIATION