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(EXP2/09) Comprehensive Energy Transport Scalings Derived from DIII-D Similarity Experiments

C. C. Petty, T. C. Luce, D. R. Baker, J. C. DeBoo, J. S. deGrassie, P. Gohil, R. J. Groebner, R. I. Pinsker, R. Prater, D. M. Thomas, R. E. Waltz

General Atomics P.O. Box 5608, San Diego, California 92186-5608, U.S.A.

F. W. Baity, M. R. Wade

Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, U.S.A.

B. W. Rice
Lawrence Livermore National Laboratory, Livermore, California 94551-9900, U.S.A.

Abstract.  The dependences of heat transport on the dimensionless plasma physics parameters has been measured for both L-mode and H-mode plasmas on the DIII-D tokamak. Heat transport in L-mode plasmas has a gyroradius scaling that is gyro-Bohm-like for electrons and worse than Bohm-like for ions, with no measurable beta or collisionality dependence; this corresponds to having an energy confinement time that scales like $\tau_{E}^{}$ $\propto$ n^0.5P^-0.5. H-mode plasmas have gyro-Bohm-like scaling of heat transport for both electrons and ions, weak beta scaling, and moderate collisionality scaling. In addition, H-mode plasmas have a strong safety factor scaling ( $\chi$ $\sim$ q²) at all radii. Combining these four dimensionless parameter scalings together gives an energy confinement time scaling for H-mode plasmas like $\tau_{E}^{}$ $\propto$ B^-1$\rho^{-3.15}_{}$$\beta^{0.03}_{}$$\nu^{-0.42}_{}$q₉₅^-1.43 $\propto$ I^0.84B^0.39n^0.18P^-0.41L^2.0, which is similar to empirical scalings derived from global confinement databases.

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