Parameter dependences of ion thermal transport due to toroidal ITG turublence

摘要

The non-liner 3-D toroidal gyrokinetic simulation code PG 3EQ is used to study toroidal ion temperature gradient (ITG) driven turbulence -a key cause of the anomalous transport that limits tokamak plasma performance. Surveys of Xi versus E 罛 and toroidal shear show that (a) the maximum growth rate is not a good predictor of the E×B shear required to suppress turbulent transport, (b) there is often a 'plateau region' in which E×B shear significantly reduces the maximum linear growth rate but not the transport and (c) the parallel velocity shear component of toroidal velocity shear can negate much of the transport reduction by the E ×　B shear.