H.R. STRAUSS

New York University, New York, NY, USA

L.E. SUGIYAMA

Massachusetts Institute of Technology, Cambridge, MA, USA

G.Y. FU, W. PARK, J.BRESLAU, D. MONTICELLO

Princeton Plasma Physics Laboratory, Princeton, NJ, USA

- Physics
- MHD
- 2 Fluid, neoclassical
- hybrid
- ``artificial sound" for parallel equilibration

- parallelization
- shared memory, OMP
- and distributed memory, MPI

- Mesh
- unstructured mesh of triangles and quadrilaterals in poloidal pl anes
- 4th order finite differencing or pseudo spectral in the toroidal direction

- initialization from the VMEC code (working on PIES)

Ideal and Resistive MHD

- Ideal MHD
- ideal limit is too low.

- Resistive MHD
- resistive ballooning modes unstable for all .
- Stellarators tend to be resistive interchange unstable, so the resistive modes are not stabilized at small resistivity, as in tokamaks.

Two fluid

- two fluid equations (Sugiyama and Park, PoP 2000)
- resistive modes are stabilized by diamagnetic drifts.
- realistic value of the Hall parameter
- Ideal modes can be stabilized, raising limit.

Hall parameter

where is toroidal mode number. Ideal modes are stable if

can be stable,

- Hot particle kinetic effects can cause TAE modes in stellarators. TAE modes are confirmed by frequency and linear scaling of growth rate with hot particle . The growth rate in a two period stellarator is lower than in a tokamak with the same profiles and average boundary shaping.

- PIES restart file used to generate M3D input file
- compared vacuum case with islands

Summary

- Two Fluid essential for equilibrium and stability
- Kinetic TAE calculations
- PIES - M3D Comparison
- need to include vacuum region for free boundary computations