Reversed-field pinch studies in the Madison Symmetric Torus

Technical Report · Sat Apr 03 04:00:00 EST 1993

DOI:https://doi.org/10.2172/10154656· OSTI ID:10154656

Hokin, S; Almagri, A; Cekic, M; Chapman, B; Crocker, N; Den Hartog, D J; Fiksel, G; Henry, J; Ji, H; Prager, S; Sarff, J; Scime, E; Shen, W; Stoneking, M; Watts, C

Studies of large-size (R = 1.5 m, a = 0.5 m), moderate current (I < 750 kA) reversed-field pinch (RFP) plasmas are carried out in the Madison Symmetric Torus in order to evaluate and improve RFP confinement, study general toroidal plasma MHD issues, determine the mechanism of the RFP dynamo, and measure fluctuation-induced transport and anomalous ion heating. MST confinement has been improved by reduction of magnetic field errors with correction coils in the primary circuit and reduction of impurities using boronization; high densities have been achieved with hydrogen pellet injection. MHD tearing modes with poloidal mode number m = 1 and toroidal mode numbers n = 5--7 are prevalent and nonlinearly couple to produce sudden relaxations akin to tokamak sawteeth. Edge fluctuation-induced transport has been measured with a variety of insertable probes. Ions exhibit anomalous heating, with increases of ion temperature occuring during strong MHD relaxation. The RFP dynamo has been studied with attention to various possible mechanisms, including motion-EMF drive, the Hall effect, and superthermal electrons. Initial profile control experiments have begun using insertable biased probes and plasma guns. The toroidal field capacity of MST will be upgraded during Summer, 1993 to allow low-current tokamak operation as well as improved RFP operation.

• Research Organization: Wisconsin Univ., Madison, WI (United States). Plasma Physics Research
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: FG02-85ER53198
• OSTI ID: 10154656
• Report Number(s): DOE/ER/53198--218; ON: DE93013464
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700310
700330
700350
CHARGED-PARTICLE TRANSPORT
FLUCTUATIONS
ION TEMPERATURE
MAGNETIC CONFINEMENT
MAGNETIC FIELDS
MHD EQUILIBRIUM
PLASMA CONFINEMENT
PLASMA HEATING
PLASMA KINETICS, TRANSPORT, AND IMPURITIES
PLASMA PRODUCTION, HEATING, CURRENT DRIVE, AND INTERACTIONS
REVERSE-FIELD PINCH
TEARING INSTABILITY