Description
By optimizing a compact stellarator quasi-omnigenous configuration[1] toward negative toroidally averaged triangularity, we demonstrate a substantial reduction in radial heat transport driven by ion-temperature-gradient (ITG) turbulence with adiabatic electrons. Crucially, this improvement is obtained without degrading other key performance metrics, including ballooning stability, neoclassical confinement, magnetic-field quasi-symmetry, and plasma volume. These results echo earlier findings in tokamaks, where negative triangularity has been associated with some of the strongest reductions in turbulence-induced transport [2]. Our study therefore suggests that toroidally averaged triangularity—an easily and rapidly computed quantity in stellarators—can be used as a practical proxy to guide stellarator optimization toward improved ITG turbulence performance, significantly lowering the computational cost of full-scale numerical optimization.
References
[1] DA Spong et al. Nuclear Fusion 6, 711 (2001)
[2] JM Duff et al. Physics of Plasmas 29, 012303 (2022)