Investigation of the electric field structure in ISX-B plasmas

Technical Report · Tue Apr 01 04:00:00 EST 1986

DOI:https://doi.org/10.2172/5888239· OSTI ID:5888239

Mathew, J.; Hallock, G. A.; Jennings, W. C.; Hickok, R. L.; Wootton, A. J.; Sigmar, D. J.

Plasma potentials have been measured for the first time in neutral-beam-heated tokamak discharges. Radial potential profiles have been obtained for coinjection, counterinjection, and balanced injection discharges as well as for ohmically heated plasmas in the Impurity Study Experiment (ISX-B) tokamak. Within experimental uncertainties, the measured values of potential are consistent with calculations based on radial momentum balance using experimental values of rotation velocities, density, and ion temperature. The measurements were made using a heavy-ion beam probe, with typical plasma conditions of I/sub p/ approx. = 150 kA, B/sub T/ approx. = 12.3 kG, n-bar/sub e/ approx. = 4 x 10/sup 13/ cm/sup -3/, and P/sub b/ approx. = 0.9 MW. A negative potential well depth of about 1.0 kV was observed in ohmically heated plasmas and increased somewhat for balanced injection. Counterinjection resulted in a significantly larger well depth of approximately 3 to 4 kV, while coinjection showed an outward-pointing electric field in the plasma interior. The particle confinement times of both ions and impurities were observed to improve with counterinjection as compared with coinjection.

• Research Organization: Rensselaer Polytechnic Inst., Troy, NY (USA); Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5888239
• Report Number(s): ORNL/TM-9386; ON: DE86008947
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700104* -- Fusion Energy-- Plasma Research-- Plasma Kinetics-Experimental-- (-1987)
BEAM INJECTION
BEAMS
CHARGED PARTICLES
ELECTRIC FIELDS
HEAVY IONS
ION BEAMS
IONS
ISX TOKAMAK
NEUTRAL ATOM BEAM INJECTION
PROBES
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS