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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 $\tau_E \propto n^{0.5}P^{-0.5}$. 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 ($\chi \sim q^2$) at all radii. Combining these four dimensionless parameter scalings together gives an energy confinement time scaling for H-mode plasmas like $\tau_E \propto B^{-1}\rho^{-3.15}\beta^{0.03}\nu^{-0.42}q_{95}^{-1.43} \propto I^{0.84}B^{0.39}n^{0.18}P^{-0.41}L^{2.0}$, which is similar to empirical scalings derived from global confinement databases.

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