VMEC2GK

VMEC equilibrium to gyrokinetics

This script takes a VMEC equilibrium file for an axisymmetric equilibrium and creates the geometric coefficient files required for a gyrokinetics run with GS2 or GX.

Requirements

Script should work on Python3 >=3.6.8 and < 3.9

• numpy
• scipy
• matplotlib
• netCDF4
• multiprocessing

Generating eikcoefs

Edit the relevant parameters in the file ./input_files/eikcoefs_final_input.txt and run the script eikcoefs_final.py

Limitations

For the moment:

• the code only works with up-down-symmetric equilibria
• there is no algorithm to handle more than 2 magnetic wells. Non-trivial to add arbitrary wells. This is only a limitation if you want to use GS2.
• only checks for infinite-n ideal-ballooning stability. There is no guarantee that the equilibrium will be peeling or kink-stable.

Relevant papers

• [Mercier C and Luc N 1974 Technical Report Commission of the European Communities Report No EUR-5127e 140 Brussels]