Ion cyclotron range of frequencies stabilization of sawteeth on Tokamak Fusion Test Reactor

Journal Article · Wed Jul 01 04:00:00 EDT 1992 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860484· OSTI ID:7105020

Phillips, C K; Hosea, J; Marmar, E; Phillips, M W; Snipes, J; Stevens, J; Terry, J; Wilson, J R; Bell, M; Bitter, M; Boivin, R; Bush, C; Cheng, C Z; Darrow, D; Fredrickson, E; Goldfinger, R; Hammett, G W; Hill, K; Hoffman, D; Houlberg, W ; Hsuan, H; Hughes, M; Jassby, D; McCune, D; McGuire, K; Nagayama, Y; Owens, D K; Park, H; Ramsey, A; Schilling, G; Schivell, J; Smithe, D N; Stratton, B; Synakowski, E; Taylor, G; Towner, H; White, R; Zweben, S ^[1]

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1. Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

Results obtained from experiments utilizing high-power ion cyclotron range of frequencies (ICRF) heating to stabilize sawtooth oscillations on Tokamak Fusion Test Reactor (TFTR) (Hawryluk {ital et} {ital al}., Plasma Phys. Controlled Fusion {bold 33}, 1509 (1991)) are reviewed. The key observations include existence of a minimum ICRF power required to achieve stabilization, a dependence of the stabilization threshold on the relative size of the ICRF power deposition profile to the {ital q}=1 volume, and a peaking of the equilibrium pressure and current profiles during sawtooth-free phases of the discharges. In addition, preliminary measurements of the poloidal magnetic field profile indicate that {ital q} on axis decreases to a value of 0.55{plus minus}0.15 after a sawtooth-stabilized period of {similar to}0.5 sec has transpired. The results are discussed in the context of theory, which suggests that the fast ions produced by the ICRF heating suppress sawteeth by stabilizing the {ital m}=1 magnetohydrodynamic (MHD) instabilities believed to be the trigger for the sawtooth oscillations. Though qualitative agreement is found between the observations and the theory, further refinement of the theory coupled with more accurate measurements of experimental profiles will be required in order to complete quantitative comparisons.

• DOE Contract Number: AC02-76CH03073
• OSTI ID: 7105020
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 4:7; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340 -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
700350* -- Plasma Production
Heating
Current Drive
& Interactions-- (1992-)
CLOSED PLASMA DEVICES
CONFINEMENT
FLUID MECHANICS
HEATING
HYDRODYNAMICS
INSTABILITY
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MECHANICS
PLASMA CONFINEMENT
PLASMA HEATING
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
STABILIZATION
TFTR TOKAMAK
THERMONUCLEAR DEVICES
TOKAMAK DEVICES