SMuK 2023 – wissenschaftliches Programm

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P: Fachverband Plasmaphysik

P 11: Poster I

P 11.43: Poster

Mittwoch, 22. März 2023, 14:00–15:30, HSZ EG

Validation of theoretical upper bounds on local gyrokinetic instabilities — •Linda Podavini, Per Helander, Gabriel Plunk, and Alessandro Zocco — Max-Planck-Institut für Plamsaphysik, Wndelsteinstraße 1, 17491 Greifswald

Turbulence in magnetic confinement fusion devices is driven by the presence of gyrokinetic microinstabilities. In the last decades these instabilities have been extensively studied considering various assumptions about plasma parameters and magnetic geometry, thus hampering a desirable unified theory.

Only recently, it was shown by Helander and Plunk [1] that it is possible to obtain universal upper bounds on the growth rates of local gyrokinetic instabilities via thermodynamic considerations. These bounds are valid for all possible microinstabilities and they are independent of the magnetic field configuration and some plasma parameters, such as the number of particle species, beta and collisions.

In this work, we compare the theoretical upper bounds on growth rates with numerical and analytical results in different geometries, including stellarator, tokamak and z-pinch. For the numerical results, linear, flux-tube simulations are obtained using the gyrokinetic code stella.

[1] P. Helander and G. G. Plunk, Physical Review Letters, 127, 155001, (2021)