Interplay between magnetic shear and triangularity in ion temperature gradient and trapped electron mode dominated plasmas

Abstract

Local gyrokinetic simulations, performed with the GENE code, are used to investigate the interaction between (negative) triangularity $\delta$ and magnetic shear $s$ , in both ion temperature gradient and trapped electron mode dominated plasmas. Magnetic shear turns out to influence in a non-trivial way the effect of negative triangularity. Also, $\delta <0$ is found to lead to a reduction of fluxes when $s>1$ but not anymore when shear is reduced. In certain parameter regimes, this effect can be inverted, up to obtaining higher fluxes when $\delta <0$ with respect to its $\delta >0$ counterpart.