1. Momentum Transport and Rotation Studies
C-Mod co-rotation generated in edge, propagates to core [Lee, Rice et al.]
Need momentum pinch just inside separatrix, and transport of SOL flows across separatrix
No nonlinear gyrokinetic simulations of momentum transport done, except for some initial work for JET by Budny, using GYRO.
Simplified quasilinear theory in slab and cylindrical geometry [Coppi, Shaing, Gurcan et al.]
PLAN:
Analytic work in toroidal geometry.
Simulate momentum transport for C-Mod plasma using GS2 & GYRO, just inside separatrix.
Study off-diagonal contributions and determine conditions for momentum pinch with respect to dominant instability (TEM/ITG). Quantify as function of driving factors.
Develop idealized edge problem, avoiding need for full edge simulation
Explore mechanisms for rotation generation related to steepness of edge profiles
Devise experiments to test
Poloidal Rotation
Poloidal rotation in excess of neoclassical reported on DIII-D [Solomon et al., PoP 05]
After finite lifetime cross-section energy dependence corrected
Error bars on gradients…also single view…
Make TRV neoclassical code available for C-Mod; implement in FITS?
Provides accurate neoclassical poloidal rotation for comparison with CXRS, HIREX Jr.
Study conditions for equilibrium poloidal rotation generation using nonlinear gyrokinetic simulations (GS2/GYRO)
Do we expect a deviation from neoclassical?
D. R. Ernst et al.
2007 C-Mod Ideas Forum