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in subjects: "Alfven Waves"  
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Resonant Toroidal Alfven Eigenmodes (RTAEs) in Neutral Beam Heated Reverse Magnetic Shear Plasmas on TFTR

Description: Resonant Toroidal Alfven Eigenmodes (RTAEs) [1, 2] excited by neutral beam ions are observed in the region of the internal transport barrier in enhanced reverse shear (ERS) plasmas on TFTR. These modes occur in multiples of the same toroidal mode number in the range n=2-4 and appear as highly localized structures near the minimum in the q-profile with frequency near to that expected for TAEs. Unlike regular TAEs, these modes are observed in plasmas where the birth velocity of beam ions is well … more
Date: November 1, 1999
Creator: Cheng, C. Z.; G. Y. Fu; Gorelenkov, N. N.; Nazikian, R. & Budny, R. V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experiments on Ion Cyclotron Damping at the Deuterium Fourth Harmonic in DIII-D

Description: Absorption of fast Alfven waves by the energetic ions of an injected beam is evaluated in the DIII-D tokamak. Ion cyclotron resonance absorption at the fourth harmonic of the deuteron cyclotron frequency is observed with deuterium neutral beam injection (f = 60 MHz, B{sub T} = 1.9 T). Enhanced D-D neutron rates are evidence of absorption at the Doppler-shifted cyclotron resonance. Characteristics of global energy confinement provide further proof of substantial beam acceleration by the rf. In m… more
Date: May 1, 1999
Creator: Pinsker, R. I.; Petty, C. C.; Baity, F. W.; Bernabei, S.; Greenough, N.; Heidbrink, W. W. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Observation of Modes at Frequencies Near the Second Alfvin Gap in TFTR

Description: Modes has been observed in the frequency range of the second Alfvenic gap in H-minority ICRF heated plasmas in TFTR. This observation is surprising in that the second gap is generally considered to be small in circular cross section plasmas. The mode is inferred to be a core mode, i.e., localized in some sense within the q=1 surface. This follows from the observation that the time dependence of the mode frequency is consistent with the changes in the central density, with the appearance of the … more
Date: April 1, 1999
Creator: E., Fredrickson.; Van Dam, J. W.; Budny, R. V.; Darrow, D.; Fu, G. Y.; Hosea, J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Low frequency RF current drive. Final report, January 1, 1988--May 31, 1997

Description: This report starts with a summary of research done on the Phaedrus Tandom Mirror concept and how this research led to the design and construction of the Phaedrus-T Tokamak. Next it gives a more detailed description of the results from the last four years of research, which include the following areas: (1) first experimental demonstration of AWCD (Alfven Wave Current Drive); (2) current drive location and loop voltage response; (3) trapping and current drive efficiency; and (4) reflectometry.
Date: May 1, 1999
Creator: Hershkowitz, N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Stability Properties of Toroidal Alfven Modes Driven by Fast Particles

Description: In this report, the issues of Alfven mode stability in advanced tokamak regimes are addressed based on recent developments in theory, computational methods, and progress in experiments. The instability of Toroidal Alfven Eigenmodes (TAE) is analyzed for spherical tokamaks, such as the National Spherical Torus Experiment NSTX at the Princeton Plasma Physics Laboratory using the NOVA-K code. Chirping modes in the Alfven frequency range observed in JT-60U during the NNBI heating at energies eb0= 3… more
Date: November 1, 1999
Creator: Cheng, C. Z.; Hill, K.; Gorelenkov, N. N.; Bernabei, S. & al, et
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Fast Particle Excitation of TAEs in NSTX

Description: A broad spectrum of TAEs may be unstable in NSTX. TAEs are found having global radial structure. Alfven continuum gap exist even at high beta plasma, when TAE modes are present. TAEs may have strong drive {gamma}/{omega} > 30%, which requires developing of nonperturbative codes for more robust calculations. Single and two mode calculations predict highest beam ion losses totaling in high beta high-q{sub 0} plasmas {approximately} 30% of the NBI ion population with FLR effects included, where… more
Date: June 1, 1999
Creator: Cheng, C. Z.; Fu, G. Y.; Gorelenkova, M. V.; Gorelenkov, N. N. & others], S. Kaye
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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