Production of high density plasma by pellet injection in TFTR

Conference · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5425517

Milora, S L; Schmidt, G L; Combs, S K; Bush, C E; Goldston, R J; Grek, B; Hawryluk, R J; Johnson, D; Mansfield, D; Park, H

High plasma densities have been produced in ohmic and neutral beam heated discharges on TFTR using a repeating pneumatic pellet injector developed at Oak Ridge National Laboratory (ORNL). Line average plasma densities as high as 1 x 10/sup 14/ cm/sup -3/ have been attained by injection of five 2.7 mm deuterium pellets ..delta..n/sub e/ = 2 x 10/sup 14/ cm/sup -3/ over a one-second interval into a stetched neutral beam pulse. Injection of a single large (4 mm) pellet in ohmic discharge has produced highly peaked profiles with nec(o) = 1.8 x 10/sup 14/ cm/sup -3/, n/sub e/(0) tau/sub E/(a) = 6.7 x 10/sup 13/ cm/sup -3/ and n/sub D/(0)Ti(0)tau/sub E/(a) = 8.8 x 10/sup 13/ cm/sup -3/ sKeV. Global confinement in these discharges approaches 0.45 seconds with a central density decay time of 2 seconds. Based on a neoclassical resistivity model and x-ray pulse-height analysis, zeff is <2 in both ohmic and beam-heated plasmas. The energy confinement properties of intermediate density (n/sub e/ (0) = 1 x 10/sup 14/ cm/sup -3/) full beam power (5.7 MW, 80 KVD/sup 0/) discharge have been studied in detail using the TRANSP code. Although the global energy confinement (approx. =2 oums at IP = 2.2 MA) is comparable to gas-fueled discharges, the confinement in the central core is considerably longer and electron heat conduction losses are smaller.

• Research Organization: Oak Ridge National Lab., TN (USA); Princeton Univ., NJ (USA). Plasma Physics Lab.
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5425517
• Report Number(s): CONF-8510266-5; ON: DE86014027
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
&amp; Production
700205 -- Fusion Power Plant Technology-- Fuel
Heating
&amp; Injection Systems
CONFINEMENT
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
PELLET INJECTION
PHYSICAL PROPERTIES
PLASMA CONFINEMENT
PLASMA DENSITY
SPECTRA
TFTR TOKAMAK
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS
X-RAY SPECTRA