Researchers have discovered a new method that allows them to manipulate the self-generated rotation of charged plasma gas within fusion facilities called tokamaks.
This new method could help move along the realization of fusion as a source of energy for generating electricity, the Princeton Plasma Physics Laboratory and DOE reported.
The huge international tokamak ITER that is currently under construction in France is so large that it will be difficult for it to provide proper rotation through external means, which is essential to its function. Rotation stabilizes instabilities in plasma, while sheared rotation (the difference in velocities between two "bands" of rotating plasma) suppresses plasma turbulence, allowing gas to retain its high temperature without increasing energy costs.
Tokamaks generally produce rotation by heating plasma with neuteral beams, causing it to spin. In intrinsic rotation, rotating particles instead accelerate the plasma in the opposite direction. The research team produced intrinsic rotation by moving the "X-point, which is the dividing point between magnetically confined plasma and plasma that has escaped confinement. This method not onlt altered the edge rotation, but also altered the rotation within the super-hot core of the plasma where the fusion reactions occurred.
The findings suggest the method could allow the X-point to be used as a "control knob" to adjust the actions within fusion plasmas, allowing researchers to access different intrinsic rotation profiles.
The findings were published in a recent edition of the journal Physical Review Letters.
