Coarse-grained gyrokinetics for the critical ion temperature gradient in stellarators
We present a modified gyrokinetic theory to predict the critical gradient that determines the linear Inhalers onset of the ion temperature gradient (ITG) mode in stellarator plasmas.A coarse-graining technique is applied to the drift curvature, entering the standard gyrokinetic equations, around local minima.Thanks to its simplicity, this novel for