numerical tokamak
Project Goals
Project Results, 
KKKKET Gyrokinetics Simulations
Related Websites
Publications
Plasma Simulation Group Page

ucla plasma simulation group

 
    A major roadblock in the development of FUSION ENERGY is the mysteriously fast transport of energy out of the PLASMA which lies inside the TOKAMAK vessel.  Our group uses computer simulations to understand the turbulence that causes this energy loss.  We specialize in studying how bulk flow can reduce this turbulence.

project goals
The primary goal of this project is to obtain a predictive capability of plasma particle and heat transport, using physics based simulation models and modern parallel computers, in different magnetic configurations so that a cost-effective design for the next generation fusion devices can be achieved.  Our 'first principles' simulations approach to model plasma transport based on the particle-in-cell method applied to the gyro-drift dynamical equations of motion in external and self consistent electric and magnetic fields.

an image of the ET Tokamak at UCLA picture of the inside of the ET Tokamak
An image of the ET Tokamak at UCLA
K
K
The inside of the ET Tokamak
K
K
Animation of potential 
fluctuations in the 
Numerical Tokamak

projects results
Gyrokinetic Simulations of Pure Global Poloidal Rotation in Tokamaks:
         These simulations are the minimum needed in resolution and particle number: 128 X 128 X 64 and 4 million respectively. The results are applicable to large aspect ratio tokamaks. Presented below are cross-section views of the potential fluctuations with red positive and blue negative. Each case is color autoscaled to the max in its own evolution. (Publications below)
Non-rotating case movie:
Knon-rotation case movie
K

Here we see trapped-ion branch ion temperature gradient mode instabilities develop through the linear phase into nonlinear saturation. These are the modes thought to be responsible for ion heat transport in tokamaks.
K

K
K
K
 

Rotating case movie:

rotating case movie

k
The rotation is global (max at half radius) with global flow shear. The overall speed is at the unity poloidal Mach number. At this speed, trapped ion orbits are destroyed and the drive for these modes vanish. You will see them start to grow, but then die back into noise before reaching nonlinear saturation. This is very good for energy confinement in tokamaks!

k

Energy evolution movie:
K
graph movie
K

The volume averaged electrostatic fluctuation energy for both cases evolves up through linear growth and then saturates. The lower the saturated energy, the better the confinement!
K
K
K
K
K
K
K
K
 

The volume averaged electrostatic fluctuation energy for both cases evolves up through linear growth and then saturates. The lower the saturated energy, the better the confinement!
Simulation Parameters

 
related websites
Research Highlights from NERSC Annual report, 1999
Numerical Tokamak Turbulence Project Home Page
Cyclone Project Home Page 
Fusion Educational web site
UCLA Electric Tokamak Home Page
Colorado University Plasma Simulation Group

K
recent publications
J.-N. Leboeuf, J. M. Dawson, V. K. Decyk, M. W. Kissick, T. L. Rhodes, and R. D. Sydora, "Effect of externally imposed and self-generated flows on turbulence and magnetohydrodynamic activity in tokamak plasmas", Physics of Plasmas 7, p. 1795-1801 (2000)

 McKee, G.R.; Murakami, M.; Boedo, J.A.; Brooks, N.H.; Burrell, K.H.; Ernst, D.R.; Fonck, R.J.; Jackson, G.L.; Jakubowski, M.; La Haye, R.J.; Messiaen, A.M.; Ongena, J.; Rettig, C.L.; Rice, B.W.; Rost, C.; Staebler, G.M.; Sydora, R.D.; Thomas, D.M.; Unterberg, B.; Wade, M.R.; West, W.P. "Impurity-induced turbulence suppression and reducedtransport in the DIII-D tokamak", Physics of Plasmas 7, p. 1870-7 (2000).

 J. M. Dawson, " Role of computer modeling of plasmas in the 21st century", Physics of Plasmas 6, p.4436-43 (1999).

 M. W. Kissick, J.-N. Leboeuf, S. C. Cowley, J. M. Dawson, V. K. Decyk, P.-A. Gourdain, J.-L. Gauvreau, P. A. Pribyl, L. W. Schmitz, R. D. Sydora, and G. R. Tynan, "Radial Electric Field Required to Suppress Ion Temperature Gradient Modes in the Electric Tokamak" , Phys. Plasmas 6, 4722-4727 (1999).

 C. D. Norton, V. Decyk, and J. Slottow, "Applying Fortran 90 and Object-Oriented Techniques to Scientific Applications," Object-Oriented Technology ECOOP'98 Workshop Reader, Ed. by Serge Demeyer and Jan Bosch, Proc. of the European Conf. on Object-Oriented Programming, Brussels, Belgium, July, 1998 [Springer LNCS, Berlin, 1998], p. 462-3 (1999).

 V. K. Decyk, C. D. Norton, and B. K. Szymanski, "How to support inheritance and run-time polymorphism in Fortran 90", Computer Physics Communications 115, p. 9-17 (1998).

Back to Plasma Simulation Group