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Direct electron heating by 60 MHz fast waves on DIII-D

Description: Efficient direct electron heating by fast waves has been observed on the DIII-D tokamak. A four strap antenna with (0,{pi},0,{pi}) phasing launched up to 1.6 MW of fast wave power with {vert bar}n{sub {parallel}}{vert bar} {approx} 11. This {vert bar}n{sub {parallel}}{vert bar} is suitable for strong electron interaction in ohmic target plasmas (T{sub e} {le} 2 keV). Ion cyclotron absorption was minimized by keeping the hydrogen fraction low ({lt}3%) in deuterium discharges and by operating at … more
Date: October 1, 1991
Creator: Petty, C. C.; Pinsker, R. I.; Mayberry, M. J.; Chiu, S. C.; Luce, T. C.; Prater, R. (General Atomics, San Diego, CA (United States)) et al.
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Partner: UNT Libraries Government Documents Department
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Fundamental and second harmonic hydrogen fast-wave heating on DIII-D

Description: Ion cyclotron resonance heating (ICRH) with fast waves has been investigated on D3-D in both the fundamental hydrogen minority (32 MHz, 2.14 T) and second harmonic hydrogen majority (60 MHz, 1.97 T) regimes. The main purpose of these experiments was to characterize the fast wave coupling and propagation in preparation for upcoming fast wave current drive (FWCD) experiments. For the fundamental minority regime, the electron and ion heating, global confinement, and radiated power fraction are com… more
Date: October 1, 1991
Creator: Petty, C. C.; Pinsker, R. I.; Mayberry, M. J.; Prater, R. (General Atomics, San Diego, CA (United States)); Porkolab, M.; Bonoli, P. T. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center) et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Fast wave current drive antenna performance on DIII-D

Description: Fast wave current drive (FWCD) experiments at 60 MHz are being performed on the DIII-D tokamak for the first time in high electron temperature, high {beta} target plasmas. A four-element phased-array antenna is used to launch a directional wave spectrum with the peak n{sub {parallel}} value ({approx equal} 7) optimized for strong single-pass electron absorption due to electron Landau damping. For this experiment, high power FW injection (2 MW) must be accomplished without voltage breakdown in t… more
Date: October 1, 1991
Creator: Mayberry, M. J.; Pinsker, R. I.; Petty, C. C.; Chiu, S. C.; Jackson, G. L.; Lippmann, S. I. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Fast Wave Heating and Current Drive in DIII-D Discharges With Negative Central Shear

Description: The noninductive current driven by fast Alfven waves (FWCD) has been applied to discharges in DIII-D with negative central shear. Driven currents as high as 275 kA have been achieved with up to 3 MW of fast wave power with the efficiency and profile as predicted by theory-based modeling. When counter-current FWCD was applied to discharges with negative central shear, the negative shear was strengthened and prolonged, showing that FWCD can help to control the current profile in advanced tokamak … more
Date: October 1, 1996
Creator: Prater, R.; Austin, M. E. & Baity, F. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Fast wave current drive antenna performance on DIII-D

Description: Fast wave current drive (FWCD) experiments at 60 MHz are being performed on the DIII-D tokamak for the first time in high electron temperature, high {beta} target plasmas. A four-element phased-array antenna is used to launch a directional wave spectrum with the peak n{sub {parallel}} value ({approx_equal} 7) optimized for strong single-pass electron absorption due to electron Landau damping. For this experiment, high power FW injection (2 MW) must be accomplished without voltage breakdown in t… more
Date: October 1, 1991
Creator: Mayberry, M. J.; Pinsker, R. I.; Petty, C. C.; Chiu, S. C.; Jackson, G. L.; Lippmann, S. I. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Fast wave at 433 MHz on FTU by a folded waveguide launcher

Description: The use of fast wave (FW) power to interact directly with electrons is a useful tool for central heating of high density, high temperature plasmas and for electron current drive (CD). Direct electron heating by FW has been observed on JET and TFTR and, although FW absorption is weak at low {beta}, successful electron heating and CD have been achieved on DIII-D at Te=2--3keV. The folded waveguide (FWG) is a promising new concept for ICRF launchers having the advantage of compact, rigid structure… more
Date: October 1, 1993
Creator: Barbato, E.; De Marco, F.; Jaeger, E. F.; Carter, M. D.; Hoffman, D. J.; Baity, F. W. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

4 MW upgrade to DIII-D FWCD system: System commissioning and initial operation

Description: The initial installation of the 4 MW fast wave current drive (FWCD) upgrade started in 1992 with the purchase of two ABB/Thomcast AG rf power amplifiers. These amplifiers cover the frequency range 30 MHz to 120 MHz. A maximum output power of over 2 MW between 30 MHz and 80 MHz and 1 MW at 120 MHz were the specification requirements. The system as installed is comprised of the two mentioned rf amplifiers, coaxial transmission and matching components, rf phase and amplitude monitoring, and a SUN … more
Date: October 1995
Creator: Cary, W. P.; Callis, R. W.; de Grassie, J. S.; Harris, T. E.; O`Neill, R. C.; Pinsker, R. I. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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