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Author: Jan G Weiland
Requested Type: Pre-Selected Invited
Submitted: 2018-02-18 09:41:44


Contact Info:
Chalmers University of Technology and Euratom-VR A
Sven Hultins gata 2
Gothenburg, Vastra Got   41296

Abstract Text:
Already in 1976, Adam et. al. found that trapped electron modes driven by the magnetic drift resonance, could have roughly a factor 4 larger growth rates when evaluated by numerical means without expansion1.This was for a kinetic description.The first corresponding fluid calculations were made in 19892. The validity of the fluid model was shown in 20153. This was for the case of drift modes in general where both the electron and ion drift resonances could be included. The symmetry of trapped electron and trapped ion branches was demonstrated in the kinetic case by Liu in 19694. The strong similarity of the trapped ion and free ions in 2d then justifies our full system of trapped electron and ITG modes2. In the fluid case the instability is very similar to a cold beam-plasma instability. Marginal stability occurs at the fluid magnetic drift resonance. This means that the ion response should not be expanded for the ITG branch and the electron response not for the TE mode5. The fluid resonance in the energy equation leads to enhanced poloidal rotation. We then recover internal transport barriers, the L-H transition and the nonlinear Dimits upshift6,7. It was also recently shown that our reactive fluid closure leads to the correct level of drift wave transport7. A further strong indication of the validity of our model is that it reproduces the experimental power scaling of the energy confinement time. The most recent result is that Alpha heating reduces the slope of the H-mode barrier of ITER (AAPPS-2017).
1. J.C. Adam, W.M. Tang and P.H. Rutherford, Phys Fluids 19, 561 ((1976)
2. J. Weiland, A. Jarmen and H. Nordman, Nucl. Fusion 29, 1810 (1989)
3. J. Weiland, C.S. Liu and A. Zagorodny, J. Plasma Physics 81, 905810101 (1985)
4. C.S. Liu, Phys. Fluids 12 1489 (1969)
5. J. Weiland Physica Scripta 90, 088009 (2015)
6. G.Q. Wang, J. Ma and J. Weiland Physica Scripta 90, 065604 (2015)
7. J. Weiland and A. Zagorodny, Phys. Plasmas 23, 102307 (2016)

Plasma Properties, Equilibrium, Stability and Transport