NSTX-U Equilibrium Diagnostic Measurement
Capabilities – January 2015
(black – available
for experiments, blue – under active development)
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Physics
Measurement
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Typical range
and coverage
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Spatial;
Temporal Resolution
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Typical
Precision
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Available
Diagnostic Techniques
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Comment
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Contact
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Coil currents
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0-130 kA
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follow pulse shape.
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1.0%
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Rogowski coil on buswork; Hall effect
transducers at power supplies
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For EFIT/LRDFIT equilibrium
reconstruction
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S. Gerhardt – PPPL
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Plasma current, Ip,
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0-2 MA
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2-5 kHz
sampling rate
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1.0%
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2 Rogowski coils around plasma outside vacuum vessel
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For EFIT/LRDFIT reconstruction
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S. Gerhardt – PPPL
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Equilibrium Poloidal Field and Flux
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Variable spatial resolution
2-5 kHz sampling rate
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1-3%
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2D
and 3D solenoids (Mirnov coils) inside vv, flux loops inside and outside vv
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For EFIT/LRDFIT reconstruction
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S. P. Gerhardt-PPPL
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Plasma Equilibrium Reconstruction
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10 mm absolute
1 ms
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Solutions
of the Grad-Shafranov Equation Constrained by Measurements
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Between shot analysis with the EFIT
code; post-experiment analysis with EFIT and LRDFIT
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S. Sabbagh – CU, J. Menard-PPPL
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Plasma kinetic energy
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> 10 kJ
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1 ms
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1 kJ
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Diamagnetic loop
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EFIT/LRDFIT constraint, uses TF coil
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S. Gerhardt - PPPL
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B field pitch (for determination of q(R) using LRDFIT or EFIT)
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3 cm core, 2 cm edge, 10 ms (target 5
ms)
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≥ 0.2°
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Motional Stark effect based on collisionally-induced-
fluorescence (MSE/CIF)
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18 channels, presently
applies correction for toroidal rotation, requires heating beam source A.
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H. Yuh, F. Levinton – Nova Photonics
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target - 3 cm core, 2 cm edge, 10 ms
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target ≥ 0.2°
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Motional Stark effect based on laser-induced-fluorescence
(MSE/LIF) using DNB
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10 channels, Requires compact, radial
DNB
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Y. Sechrest, F. Levinton – Nova Photonics
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TBD (probably ~2 MHz)
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1
mm radial polarimeter
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Provides line integral constraint, in
conjunction with electron
density profile input
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S. Kubota - UCLA
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Compact array of microwave receiving antennas. Two antennas can
be configured to launch microwaves for imaging reflectometry.
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Measures plasma emission up to 40 GHz with sub-millisecond time
resolution.
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Synthetic Aperture Microwave Imaging (SAMI)
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Measures EBW emission as a function of poloidal and toroidal
angle, allowing high radial resolution measurements of edge magnetic field
pitch. Also can be configured for imaging relectometry to measure edge plasma
flows.
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G. Taylor – PPPL
R. Vann – University of York, UK
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B field magnitude, P(R)
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5 cm core, 2 cm edge, 10 ms
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>5 Gauss
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Motional Stark effect based on laser-induced-fluorescence
(MSE/LIF) using DNB
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10 channels, Requires compact, radial
DNB
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Y. Sechrest, F. Levinton – Nova Photonics
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