Dynamo-free plasma in the reversed-field pinch: Advances in understanding the reversed-field pinch improved confinement mode
نویسندگان
چکیده
J. K. Anderson, J. Adney, A. Almagri, A. Blair, D. L. Brower, M. Cengher, B. E. Chapman, S. Choi, D. Craig, D. R. Demers, D. J. Den Hartog, B. Deng, W. X. Ding, F. Ebrahimi, D. Ennis, G. Fiksel, C. B. Forest, P. Franz, J. Goetz, R. W. Harvey, D. Holly, B. Hudson, M. Kaufman, T. Lovell, L. Marrelli, P. Martin, K. McCollam, V. V. Mirnov, P. Nonn, R. O’Connell, S. Oliva, P. Piovesan, S. C. Prager, I. Predebon, J. S. Sarff, G. Spizzo, V. Svidzinski, M. Thomas, and M. D. Wyman The University of Wisconsin, Madison, Wisconsin and the Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas The University of California at Los Angeles, Los Angeles, California 90095 CompX, Del Mar, California 92014 Rensselaer Polytechnic Institute, Troy, New York 12180 Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Padova, Italy
منابع مشابه
New Observations Concerning the Origin and Consequences of MHD Activity in the MST Reversed Field Pinch
Reversed Field Pinch (RFP) plasmas exhibit a broad spectrum of MHD activity. The instability underlying much of this activity in the standard RFP discharge has been identified as resistive tearing and is well modelled by nonlinear, resistive MHD. In recent years two additional types of discharge have been produced: those with reduced tearing activity leading to improved confinement and those wi...
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Operation of a heavy ion beam probe (HIBP) on a reversed field pinch is unique from other toroidal applications because the magnetic field is more temporal and largely produced by plasma current. Improved confinement, produced through the transient application of a poloidal electric field which leads to a reduction of dynamo activity, exhibits gradual changes in equilibrium plasma quantities. A...
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Magnetic field fluctuations (and the associated current perturbation) have been measured in the core of a high-temperature reversed-field pinch using a newly developed fast-polarimetry system. Radial magnetic field fluctuation levels of approximately 1% are measured in standard-reversed-field pinch discharges which increase to approximately 4% during the sawtooth crash (enhanced dynamo). The fl...
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Results obtained on the Madison Symmetric Torus (MST) reversed-field pinch [Fusion Technol. 19, 13 1 ( 199 1) ] after installation of the design poloidal field winding are presented. Values of Be, = 2~, nd) T&/B s (a) 12% are achieved in low-current (I = 220 kA) operation; here, n, and T, are central electron density and temperature, and Be (a) is the poloidal magnetic field at the plasma edge....
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The first experimental study of the MHD dynamo in a quasi-single-helicity (QSH) reversed-field pinch toroidal plasma is presented. In QSH plasmas, a dominant wave number appears in the velocity fluctuation spectrum. This velocity component extends throughout the plasma volume and couples with magnetic fluctuations to produce a significant MHD dynamo electric field. The narrowing of the velocity...
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First measurements of the current-density profile in the core of a high-temperature reversed-field pinch are presented. The current-density profile is observed to peak during the sawtooth cycle and broaden promptly at the crash. This change in profile can be linked to magnetic relaxation and the dynamo which is predicted to drive antiparallel current in the plasma core. For high-confinement dis...
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