Interpretation of the I-Regime and transport associated with relevant heavy particle modes

Journal Article · Sun Jan 15 00:00:00 EST 2012 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3671944· OSTI ID:22043563

Coppi, B; Zhou, T ^[1]

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1. Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

The excitation of a novel kind of heavy particle [B. Coppi et al., Phys. Rev. Lett. 17, 377 (1966); B. Coppi and T. Zhou, MIT(LNS) Report HEP 09/04, 2009, Cambridge, MA [Phys. Lett. A 375, 2916 (2011)]] mode at the edge of the plasma column is considered as the signature of the I-confinement Regime [R. McDermott et al., Bull. Am. Phys. Soc. 53, 112 (2008); R. McDermott et al., Phys. Plasmas 16, 056103 (2009); E. Marmar et al., Bull. Am. Phys. Soc. 54, 97 (2009); D. Whyte et al., Nucl. Fusion 50, 105005 (2010); A. Hubbard et al., Phys. Plasmas 18, 056115 (2011)]. The outward transport of impurities produced by this mode is in fact consistent with the observed expulsion of them from the main body of the plasma column (a high degree of plasma purity is a necessary feature for fusion burning plasmas capable of approaching ignition). Moreover, the theoretically predicted mode phase velocity, in the direction of the electron diamagnetic velocity, has been confirmed by relevant experimental analyses [I. Cziegler, private communication (2010)] of the excited fluctuations (around 200 kHz). The plasma ''spontaneous rotation'' in the direction of the ion diamagnetic velocity is also consistent, according to the accretion theory [B. Coppi, Nucl. Fusion 42, 1 (2002)] of this phenomenon, with the direction of the mode phase velocity. Another feature of the mode that predicted by the theory is that the I-Regime exhibits a knee of the ion temperature at the edge of the plasma column, but not one of the particle density as the mode excitation factor is the relative main ion temperature gradient exceeding the local relative density gradient. The net plasma current density appearing in the saturation stage of the relevant instability, where the induced particle and energy fluxes are drastically reduced, is associated with the significant amplitudes of the poloidal magnetic field fluctuations [D. Whyte et al., Nucl. Fusion 50, 105005 (2010); A. Hubbard et al., Phys. Plasmas 18, 056115 (2011)] observed to accompany the density fluctuations. The theoretical implications of the significant electron temperature fluctuations [A. White, private communication (2011)] observed are discussed.

• OSTI ID: 22043563
• Journal Information: Physics of Plasmas, Vol. 19, Issue 1; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOUNDARY LAYERS
CONFINEMENT
DENSITY
ELECTRIC CURRENTS
ELECTRON TEMPERATURE
EXCITATION
FLUCTUATIONS
INSTABILITY
ION TEMPERATURE
IONS
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
PHASE VELOCITY
PLASMA
PLASMA DENSITY
PLASMA DIAMAGNETISM
PLASMA IMPURITIES
ROTATION
TEMPERATURE GRADIENTS