Chen Geng

I am a theoretical PhD student at University of York. My research focuses on the physics drive of the unstable collisionless microtearing modes (MTMs) in fusion plasmas. My supervisors are Prof Howard Wilson and Dr David Dickinson. MTMs can lead to anomalous heat transport in tokamak devices, therefore they are important for improving the confinement. Previous theories show that the drive of the mode requires finite collision frequency; however, we have found collisionless MTM-like instabilities in GS2 simulations in both slab and toroidal geometries. To date, we have proved that, in slab geometry, the mode is associated with a higher order harmonic of the electron temperature gradient (ETG) mode, where the finite Larmor radius (FLR) effects from electrons are important for the physics model. The physics of the toroidal mode is to be further studied.