My current research interests are about tokamak micro-turbulence. At the core, we recently discovered a natural fueling mechanism that helps to maintain the main core deuterium and tritium (DT) density profiles. In H-mode plasmas dominated by ion-temperature gradient (ITG) driven turbulence, cold DT ions near the edge will naturally pinch radially inward towards the core. Fueling using shallow pellet injection or supersonic gas jets is augmented by an inward pinch of could DT fuel. This effect may also apply to the edge pedestal density buildup and explain the density peaking problem of the core.
The other subject I am studying is gyrokinetic simulations of the edge pedestal. The turbulence from simulation results peaks at the position of strongest pressure gradient and hence the bottom of Er. The dominant linear instability appears to be caused by the strong density gradient. It requires kinetic electrons but is not due to trapped electrons, and it is nearly insensitive to ion and electron temperature gradients. There are signs of electron drift wave and kinetic ballooning mode. The characteristics of the pedestal instability are important in determining the width and height of the pedestal.