Enhanced lower hybrid penetration via intense multi-microsecond pulses

Conference · Tue Jan 01 00:00:00 EST 1991

OSTI ID:5003847

Cohen, R H; Rognlien, T D ^[1]; Bonoli, P T; Porkolab, M ^[2]

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1. Lawrence Livermore National Lab., CA (United States)
2. Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center

Applying lower-hybrid power in short, intense pulses can overcome Landau damping, allowing penetration into the core of reactor-grade plasmas. We present theoretical description of the absorption which accounts for transient collisional effects as well as nonlinear broadening of the resonant plateau. We show results from ray-tracing calculations which include the nonlinear absorption. We also derive the conditions required for pump depletion by parametric instabilities, and assess density depletion by ponderomotive effects, scattering by low-frequency background fluctuations, and filamentation. Consideration of all of the aforementioned effects as well as potential source availability and launcher requirements leads to the consideration of scenarios based on 5--10 GW 30--100 {mu}s pulses for the ITER Conceptual Design. Experimental tests of the concept can be done by launching waves with high enough parallel wavenumber that the resonant electrons are only moderately far out on the tail of the distribution function. The experiments could entail checking the predicted variation of the penetration with the duration and peak power of the pulses as well as the launcher area. We give sample experimental parameters for the Microwave Tokamak Experiment (MTX), Alcator C-Mod, Versator, and D3-D. 15 refs., 3 figs.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5003847
• Report Number(s): UCRL-JC-108019; CONF-910869-20; ON: DE92002180; TRN: 91-031412
• Resource Relation: Conference: 9. topical conference on radio frequency power in plasmas, Charleston, SC (United States), 12-14 Aug 1991
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
TOKAMAK DEVICES
LOWER HYBRID HEATING
ABSORPTION
LANDAU DAMPING
PARAMETRIC INSTABILITIES
PENETRATION DEPTH
PULSES
TESTING
CLOSED PLASMA DEVICES
DAMPING
HEATING
HIGH-FREQUENCY HEATING
INSTABILITY
PLASMA HEATING
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
THERMONUCLEAR DEVICES
700101* - Fusion Energy- Plasma Research- Confinement
Heating
& Production