Gyrokinetics

A vital challenge for magnetic fusion is to improve plasma confinement by reducing the strength of turbulence. Turbulence scatters particles across magnetic field lines, thereby causing the plasma to leak particles and energy. This limits the achievable temperature gradient and determines whether the core of the plasma is hot enough for fusion reactions to occur. Understanding and predicting turbulence is a titanic theoretical challenge that we address here at SPC using the gyrokinetic model. This is a five-dimensional system of nonlinear integro-differential equations tailored to the unique plasma conditions in the core of fusion devices. Although analytic solutions are possible in simplified limits, the gyrokinetic equations are typically solved using some of the world’s largest supercomputers. In this way, we gain unrivaled insight into the physics of turbulence, as we strive to understand how to achieve the best possible plasma performance.