PPPL-4063 is available in <a href="PPPL-4063.pdf">pdf</a> format (1.4 MB).

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<b>Plasma Shape Control on the National Spherical Torus Experiment (NSTX) 
using Real-time Equilibrium Reconstruction</b>
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<b>Authors:</b> D.A. Gates, J.R. Ferron, M. Bell, T. Gibney, R. Johnson, R.J. Marsala, D. Mastrovito, J.E. Menard, D. Mueller, B. Penaflor, S.A. Sabbagh, and T. Stevenson
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<b>Date of PPPL Report:</b> April 2005
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<b>Published in:</b> Nuclear Fusion <b>46</b>:1 (January 2006) 17&ndash;23</p>


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Plasma shape control using real-time equilibrium reconstruction has been implemented on the National Spherical Torus Experiment (NSTX). The rtEFIT code originally developed for use on DIII-D was adapted for use on NSTX. The real-time equilibria provide calculations of the flux at points on the plasma boundary, which is used as input to a shape control algorithm known as isoflux control. The flux at the desired boundary location is compared to a reference flux value, and this flux error is used as the basic feedback quantity for the poloidal-field coils on NSTX. The hardware that comprises the control system is described, as well as the software infrastructure. Examples of precise boundary control are also presented.




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