Soft X-ray Tangential Imaging of the NSTX Core Plasma by Means of a MPGD Pin-hole Camera [electronic resource].

Published: Washington, D.C. : United States. Dept. of Energy. Office of Science, 2003.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
Physical Description: 864 Kilobytes pages : digital, PDF file
Additional Creators: United States. Department of Energy. Office of Science and United States. Department of Energy. Office of Scientific and Technical Information

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Summary

A fast X-ray system based on a Micro Pattern Gas Detector has been used, for the first time, to investigate emission from the plasma core of the National Spherical Tokamak eXperiment (NSTX) at the Princeton Plasma Physics Laboratory. The results presented in this work demonstrate the capability of such a device to measure with a time resolution of the order of 1 ms the curvature and the elongation of the X-ray iso-emissivity contours, under various plasma conditions. Also, comparisons with the magnetic surface structure calculated by the EFIT code show good agreement between reconstructed flux surface and the soft X-ray emissions (SXR) for poloidal beta values up to 0.6. For greater values of beta, X-ray iso-emissivity contours become circular, while magnetic flux surface reconstructions yield elongation 1.5 < k < 2.2. The X-ray images have been acquired with a (statistical) signal to noise ratio (SNR) per pixel of about 30. Thanks to the direct and efficient X-ray conversion and its operation in a photon counting mode, this new diagnostic tool allows the routine investigation of the plasma core with a sampling rate of 1 kHz and extremely high SNR under all experimental conditions in NSTX.

Report Numbers

E 1.99:pppl-3844
pppl-3844

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Note

Published through SciTech Connect.
07/24/2003.
"pppl-3844"
R. Kaita; S.A. Sabbagh; M. Finkenthal; D. Pacella; D. Stutman; M. Leigheb; R. Bellazzini; A. Brez.
Princeton Plasma Physics Lab., NJ (US)

Type of Report and Period Covered Note

Topical;

Funding Information

AC02-76CH03073

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