PPPL-3485 is available in <a href="PPPL-3485.pdf">pdf</a> or 
<a href="PPPL-3485.ps">postscript</a> formats.

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<b>Status of Far Infrared Tangential Interferometry/Polarimetry (FIReTIP) on NSTX</b>
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Authors: H.K. Park, S. Edwards, L. Guttadora, B. Deng, C.W. Domier, K.C. Lee, M. Johnson, and N.C. Luhmann, Jr.
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<b>Date of PPPL Report:</b> August 2000
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<b>To be presented at:</b> the 24th International Infrared and Millimeter Waves (IR&amp;M) Conference to be held in Beijing, China, September 11-15, 2000.</p>

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The Influence of paramagnetism and diamagnetism will significantly alter the vacuum toroidal magnetic field in the spherical torus. Therefore, plasma parameters dependent upon B<sub>T</sub> such as the q-profile and the local beta value need an independent measurement of B<sub>T</sub>(r,t). The multi-chord Tangential Far Infrared Interferometer/Polarimeter (FIReTIP) system currently under development for the National Spherical Torus Experiment (NSTX) will provide temporally and radially resolved toroidal field profile [B<sub>T</sub>(r,t)] and 2-D electron density profile [n<sub>e</sub>(r,t)] data. A two-channel interferometer will be operational this year and the full system will be ready by 2002.
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