The use of nearaxis magnetic fields for stellarator turbulence simulations
Abstract
The design of turbulence optimized stellarators has so far relied on threedimensional equilibrium codes such as VMEC in order to find the minimum of a given objective function. In this work, we propose a complimentary approach based on the nearaxis expansion to compute the geometry parameters of neoclassicaly optimized stellarators used in turbulence studies. As shown here, the nearaxis expansion can be a reasonable approximation of the geometric parameters relevant for turbulence and stability simulations of the core of existing optimized stellarator designs. In particular, we examine the geometry coefficients that appear in the gyrokinetic equation, the driftreduced fluid equations and the ideal ballooning equation. This approach may allow for the development of new stellarator optimization techniques significantly faster than conventional methods.
 Publication:

Plasma Physics and Controlled Fusion
 Pub Date:
 January 2021
 DOI:
 10.1088/13616587/abc862
 arXiv:
 arXiv:2008.09057
 Bibcode:
 2021PPCF...63a4001J
 Keywords:

 magnetic confinement;
 plasma turbulence;
 nuclear fusion;
 MHD;
 gyrokinetics;
 Physics  Plasma Physics
 EPrint:
 29 pages, 14 figures