(a) Spectrogram of Mirnov coil [black-1, red-2, green-3, blue-4, cyan-5, magenta-6]. (b) Voltage for neutral beam sources “A,” “B,” and “C.” (c) Neutron rate (black) and total injected beam power (red). (d) Plasma current.
(a) Electron density profile. (b) Electron (red) and ion (black) temperature profiles. (c) Rotation profile at 0.285 s for shot shown in Fig. 1.
Cross section of NSTX showing locations of soft x-ray camera chords (red and blue), range of reflectometer array measurements (green bar), and toroidal arrays of Mirnov coils (black squares). Blue and red arcs are tangency radii for soft x-ray chords. Solid black curve is poloidal projection of limiter surfaces.
(a) Spectrogram of magnetic fluctuations showing sequence of avalanche events; colors indicate toroidal mode numbers [black-1, red-2, green-3, blue-4, cyan-5, magenta-6]. (b) Neutron rate showing drops of at avalanches.
(a) Spectrogram of 50 GHz interferometer. (b) rms fluctuation level from 30 to 200 kHz of 50 GHz (red), 42 GHz (blue), and 30 GHz (green) reflectometers. (c) rms fluctuation level from 30 to 200 kHz for Mirnov coil (black) and 50 GHz reflectometer (red).
(a) Local soft x-ray emissivity (solid lines) and chord integrated (dashed lines) profiles. (b) Chord integrated soft x-ray fluctuations for mode (red-upper camera, blue-lower camera).
Polarization measurement of edge magnetic fluctuations. (a) Relative phase of toroidal Mirnov coil array (blue squares), Mirnov coil oriented to measure toroidal fluctuations (red circle). (b) Amplitudes of magnetic fluctuations. (c) Lissajous figure showing polarization of magnetic fluctuations.
Energy spectrum of fast ions from tangentially viewing NPA and neutron rate showing drops of at avalanches.
TRANSP simulation of neutron rate (in red) assuming He prefill, injection of deuterium neutral beams and recycling of 13% D, and 87% He compared to measured rate (black).
Ion distribution function at on the outboard midplane as calculated in TRANSP.
q-profiles from LRDFIT equilibrium reconstructions at time of initial TAE activity, 0.25 s (blue), at time of avalanche being analyzed, 0.285 s (green), and comparison of q-profiles for shots 124 780 (red) and 124 781 (black).
Continuum as calculated with NOVA for the modes. Also shown, on right, are representative eigenmode solutions. Solutions found in Boozer coordinates (blue), equal arc coordinates (red), and higher resolution equal arc coordinates (black).
Three “degenerate” eigenmodes of the equal arcs solutions shown in Fig. 11.
(a) Spectrogram showing TAE activity. (b) Evolution of q(0) and deduced from equilibrium reconstruction and (c) neutron rate.
Variations in the core q-profile for the NOVA simulations shown in Fig. 13.
Continuum corresponding to the four q-profile variations shown in Fig. 12. The corresponding eigenmodes for each q-profile are shown to the right (labeled by the frequency in kilohertz).
TAE gap corrected for sheared rotation. Eigenmodes are shown to the right; the numbers indicate the frequency in kilohertz.
Simulated density profiles at peak and minimum for mode at half of the peak amplitude: blue—density perturbation from displacement, red—density perturbation from displacement and compression, scaled up by 2.
Comparison of reflectometer data with NOVA eigenmode structures for four modes: (a) 85.2 kHz with no Doppler corrections, (b) 69.4 kHz with no Doppler corrections, (c) 115.2 kHz with Doppler corrections, and (d) 108.8 kHz with Doppler correction.
Pitch of magnetic fluctuations relative to equilibrium field; black–NOVA and red-experiment.
Best NOVA eigenmode fits for the and modes.
The percent of fast ions lost vs normalized mode amplitudes (red), losses with only mode (blue).
The four bars indicate percentages of fast-ion losses in the indicated energy ranges.
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