Turbulence in stellarators with precise quasisymmetry

We study the turbulence properties of the recently obtained stellarator configurations with precise quasisymmetry [1] using the gyrokinetic code stella [2]. The linear growth rates and nonlinear turbulence levels in multiple flux tubes are compared, using both adiabatic and kinetic electron models. We furthermore investigate whether, in a regime of strongly driven ion temperature gradient turbulence, the quasisymmetric configurations exhibit critical balance scalings similar to tokamaks [3]. Finally, we study the non-adiabatic response of passing electrons [4], which is significant in the precisely quasisymmetric configurations [1] due to their low magnetic shear, affecting both the linear growth rates at low binormal wavenumbers and the saturated turbulence levels.

[1] M. Landreman and E. Paul, Physical Review Letters 128 (2022)

[2] M. Barnes, F. Parra and M. Landreman, Journal of Computational Physics 391 (2019)

[3] M. Barnes, F. Parra and A. Schekochihin, Physical Review Letters 107 (2011)

[4] J. Dominski et al., Physics of Plasmas 22 (2015)