A Real-Time Velocity Diagnostic For NSTX
Authors: M. Podesta and R.E. Bell
Abstract:
A new system for fast measurements of the plasma toroidal velocity has been installed on the
National Spherical Torus Experiment, NSTX [M. Ono et al., Nucl. Fusion 40, 557 (2000)]. The
diagnostic, based on active charge-exchange recombination spectroscopy, can measure at up to six
radial locations with maximum sampling rate of 5 kHz. The system is interfaced in real time with the
NSTX Plasma Control System, in order to feed back on plasma velocity by means of actuators such
as neutral beams and external coils. The paper describes the design criteria and implementation of
the diagnostic. Examples from the initial tests of the system during neon glows are also discussed.
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Submitted to: Review of Scientific Instruments (December 2011)
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Download PPPL-4716 (pdf 294 MB 6 pp)
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