Theory of ion Bernstein wave induced shear suppression of turbulence

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · Physics of Plasmas; (United States)

DOI:https://doi.org/10.1063/1.870650· OSTI ID:7067711

Craddock, G G ^[1]; Diamond, P H ^[2]; Ono, M; Biglari, H ^[3]

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1. National Energy Research Supercomputer Center, Lawrence Livermore National Laboratory, Livermore, California 94551-9900 (United States)
2. University of California at San Diego, La Jolla, California 92093-0319 (United States) General Atomics, La Jolla, California 92138 (United States)
3. Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

The theory of radio frequency induced ion Bernstein wave- (IBW) driven shear flow in the edge is examined, with the goal of application of shear suppression of fluctuations. This work is motivated by the observed confinement improvement on IBW heated tokamaks [Phys. Fluids B [bold 5], 241 (1993)], and by previous low-frequency work on RF-driven shear flows [Phys. Rev. Lett. [bold 67], 1535 (1991)]. It is found that the poloidal shear flow is driven electrostatically by both Reynolds stress and a direct ion momentum source, analogous to the concepts of helicity injection and electron momentum input in current drive, respectively. Flow drive by the former does not necessarily require momentum input to the plasma to induce a shear flow. For IBW, the direct ion momentum can be represented by direct electron momentum input, and a charge separation induced stress that imparts little momentum to the plasma. The derived [ital E][sub [ital r]] profile due to IBW predominantly points inward, with little possibility of direction change, unlike low-frequency Alfvenic RF drive. The profile scale is set by the edge density gradient and electron dissipation. Due to the electrostatic nature of ion Bernstein waves, the poloidal flow contribution dominates in [ital E][sub [ital r]]. Finally, the necessary edge power absorbed for shear suppression on Princeton Beta Experiment-Modified (PBX-M) [9[ital th] [ital Topical] [ital Conference] [ital on] [ital Radio] [ital Frequency] [ital Power] [ital in] [ital Plasmas], Charleston, SC, 1991 (American Institute of Physics, New York, 1991), p. 129] is estimated to be 100 kW distributed over 5 cm.

• DOE Contract Number: W-7405-ENG-48; FG03-88ER53275
• OSTI ID: 7067711
• Journal Information: Physics of Plasmas; (United States), Journal Name: Physics of Plasmas; (United States) Vol. 1:6; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
ALFVEN WAVES
BERNSTEIN MODE
CLOSED PLASMA DEVICES
CONFINEMENT
ELECTROMAGNETIC RADIATION
FLUCTUATIONS
HEATING
HYDROMAGNETIC WAVES
OSCILLATION MODES
PLASMA CONFINEMENT
PLASMA HEATING
RADIATIONS
RADIOWAVE RADIATION
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TURBULENCE
VARIATIONS