Search Results - "FONCK, R"

Magnetic Turbulence and Current Drive during Local Helicity Injection by Richner, N J, Bodner, G M, Bongard, M W, Fonck, R J, Nornberg, M D, Reusch, J A

“…Magnetic measurements during dc helicity injection tokamak startup indicate Alfvénic turbulence in the injected current streams mediates magnetic relaxation…”
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Observation of the L-H confinement bifurcation triggered by a turbulence-driven shear flow in a tokamak plasma by Yan, Z, McKee, G R, Fonck, R, Gohil, P, Groebner, R J, Osborne, T H

“…Comprehensive 2D turbulence and eddy flow velocity measurements on DIII-D demonstrate a rapidly increasing turbulence-driven shear flow that develops ∼100  μs…”
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Noninductively Driven Tokamak Plasmas at Near-Unity Toroidal Beta by Schlossberg, D J, Bodner, G M, Bongard, M W, Burke, M G, Fonck, R J, Perry, J M, Reusch, J A

“…Access to and characterization of sustained, toroidally confined plasmas with a very high plasma-to-magnetic pressure ratio (β_{t}), low internal inductance,…”
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Detection of zero-mean-frequency zonal flows in the core of a high-temperature tokamak plasma by Gupta, D K, Fonck, R J, McKee, G R, Schlossberg, D J, Shafer, M W

“…A low-frequency, spectrally broad (Deltaf approximately 10 kHz) poloidal flow structure that peaks near zero frequency is observed in time-resolved…”
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High Confinement Mode and Edge Localized Mode Characteristics in a Near-Unity Aspect Ratio Tokamak by Thome, K E, Bongard, M W, Barr, J L, Bodner, G M, Burke, M G, Fonck, R J, Kriete, D M, Perry, J M, Schlossberg, D J

“…Tokamak experiments at near-unity aspect ratio A≲1.2 offer new insights into the self-organized H-mode plasma confinement regime. In contrast to conventional…”
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Effects of Injected Current Streams on MHD Equilibrium Reconstruction of Local Helicity Injection Plasmas in a Spherical Tokamak by Weberski, J. D., Bongard, M. W., Diem, S. J., Fonck, R. J., Goetz, J. A., Nornberg, M. D., Reusch, J. A., Schaefer, C. E., Sontag, A. C.

“…Open field line currents are intrinsic to DC helicity injection plasma startup and pose a challenge for inferring the plasma equilibrium with standard…”
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Observation of coherent sheared turbulence flows in the DIII-D Tokamak by Jakubowski, M, Fonck, R J, McKee, G R

“…Time-resolved measurements of the turbulent density flow field in a tokamak plasma reveal low-frequency ( approximately 15 KHz), coherent oscillations in the…”
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Localized turbulence suppression and increased flow shear near the q=2 surface during internal-transport-barrier formation by Shafer, M W, McKee, G R, Austin, M E, Burrell, K H, Fonck, R J, Schlossberg, D J

“…Broadband turbulent fluctuations in the plasma density are transiently suppressed when low-order rational q surfaces first appear in negative central magnetic…”
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Tokamak startup using point-source dc helicity injection by Battaglia, D J, Bongard, M W, Fonck, R J, Redd, A J, Sontag, A C

“…Startup of a 0.1 MA tokamak plasma is demonstrated on the ultralow aspect ratio Pegasus Toroidal Experiment using three localized, high-current density sources…”
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Measurement of peeling mode edge current profile dynamics by Bongard, M W, Fonck, R J, Hegna, C C, Redd, A J, Schlossberg, D J

“…Peeling modes, an instability mechanism underlying deleterious edge localized mode (ELM) activity in fusion-grade plasmas, are observed at the edge of limited…”
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Multitude of core-localized shear Alfvén waves in a high-temperature fusion plasma by Nazikian, R, Berk, H L, Budny, R V, Burrell, K H, Doyle, E J, Fonck, R J, Gorelenkov, N N, Holcomb, C, Kramer, G J, Jayakumar, R J, La Haye, R J, McKee, G R, Makowski, M A, Peebles, W A, Rhodes, T L, Solomon, W M, Strait, E J, Vanzeeland, M A, Zeng, L

“…Evidence is presented for a multitude of discrete frequency Alfvén waves in the core of magnetically confined high-temperature fusion plasmas. Multiple…”
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Impurity-induced suppression of core turbulence and transport in the DIII-D tokamak by McKee, G, Burrell, K, Fonck, R, Jackson, G, Murakami, M, Staebler, G, Thomas, D, West, P

“…Turbulence is significantly reduced in a tokamak plasma as a result of neon seeding of an L-mode discharge. Correspondingly, confinement is improved and…”
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The Formation of a Tokamak-like Plasma in Initial Experiments Using an Outboard Plasma Gun Current Source by Battaglia, D. J., Bongard, M. W., Fonck, R. J., Redd, A. J., Sontag, A. C.

“…Solenoid-free tokamak startup via point-source DC helicity injection is demonstrated on the Pegasus Toroidal Experiment using a high current density, low…”
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Non-inductive production of ST plasmas with washer gun sources on the pegasus toroidal experiment by EIDIETIS, N. W, FONCK, R. J, GARSTKA, G. D, UNTERBERG, E. A, WINZ, G. R

“…Formation of tokamak-like plasmas via electrostatic helicity injection in the ultra-low aspect ratio Pegasus Toroidal Experiment is reported. Two low-impurity,…”
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Excitation of toroidal alfven eigenmodes in TFTR by WONG, K. L, FONCK, R. J, COHEN, S, HAMMETT, G. W, JOBES, F. C, MEADE, D. M, MEDLEY, S. S, MUELLER, D, NAGAYAMA, Y, OWENS, D. K, SYNAKOWSKI, E. J, PAUL, S. F, ROBERTS, D. R, FREDRICKSON, E. D, NAZIKIAN, R, PARK, H. K, BELL, M, BRETZ, N. L, BUDNY, R

“…Deuterium neutral beams with energies up to 110 keV were injected into TFTR (Tokamak Fusion Test Reactor) plasmas at low magnetic field such that the beam…”
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Point-Source Helicity Injection Current Drive System for the Pegasus Toroidal Experiment by Redd, A. J., Battaglia, D. J., Bongard, M. W., Fonck, R. J., Hinson, E. T., Kujak-Ford, B. A., Lewicki, B. T., Sontag, A. C., Winz, G. R.

“…Recent Pegasus experiments are developing solenoid-free startup techniques using point-source magnetic helicity injection. These plasma sources, called “plasma…”
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Long-wavelength density turbulence in the TFTR Tokamak by FONCK, R. J, COSBY, G, DURST, R. D, PAUL, S. F, BRETZ, N, SCOTT, S, SYNAKOWSKI, E, TAYLOR, G

“…Long-wavelength ([ital k][sub [perpendicular]][rho][sub [ital i]][lt]1) density turbulence has been measured with good spatial localization in the core region…”
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Magnetic field pitch-angle measurments in the PBX-M tokamak using the motional Stark effect by Levinton, FM, Fonck, RJ, Gammel, GM, Kaita, R, Kugel, HW, Powell, ET, Roberts, DW

“…Polarimetry measurements of the Doppler-shifted H{sub {alpha}} emission from a neutral hydrogen beam on the PBX-M tokamak have been employed in a novel…”
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Attainment of High Normalized Current by Current Profile Manipulation in the Pegasus Toroidal Experiment by Garstka, G. D., Unterberg, E. A., Battaglia, D. J., Bongard, M. W., Eidietis, N. W., Fonck, R. J., Frost, M. J., McGarry, M. B., Sontag, A. C., Squires, B. J., Winz, G. R.

“…Large stable values of normalized current I N are achievable in spherical tori due to the large gradient of the toroidal field across the plasma. This allows…”
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Images of turbulence in a tokamak plasma by McKee, G.R., Fenzi, C., Fonck, R.J.

“…Two-dimensional measurements of density fluctuations in the DIII-D tokamak, obtained with the Beam Emission Spectroscopy diagnostic, have allowed for…”
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