Equilibrium tools

DREAM provides some Python classes and graphical tools for working with magnetic equilibria in various formats. As described on the page about the _radialgrid-numerical, DREAM uses a LUKE format for equilibrium data. We however also provide a number of classes for converting data from other formats to the LUKE format. Currently, data can be exported from ASDEX Upgrade shotfiles and EQDSK files.

eqget GUI

The eqget GUI can be launched by running the Python script tools/eqget/eqget.py. It allows you to load and visualize magnetic equilibrium data in a number of supported formats (listed above).

Python classes

A number of scripts are provided for working with magnetic equilibria for DREAM. At the time of writing, the following scripts are available:

• AUG.py – loading data from ASDEX Upgrade shotfiles

• EQDSK.py – class for loading data from EQDSK files

• EqFile.py – loading data from LUKE files (standard format used in DREAM)

Examples

ASDEX Upgrade shotfiles

import AUG

...
eq = AUG.get_LUKE(shot=shot, time=time, npsi=80, ntheta=80, filename=None)

# eq.keys() = ['id','Rp','psi_apRp','theta','ptx','pty','ptBx','ptBy','ptBPHI']

EQDSK files

from EQDSK import EQDSK

...
eq = EQDSK(filename, cocos=1, process=True, override_psilim=False)
luke_eq = eq.get_LUKE(npsi=80, ntheta=80)
# or
eq.save_LUKE(filename, npsi=80, ntheta=80)

Note

The parameter override_psilim can be used to work around poorly resolved EQDSK equilibria, for which the poloidal flux of the last closed flux surface (LCFS) is inaccurately specified in the file. If override_psilim=True, the flux surface with psin=1-2e-4 (psin being the normalized poloidal flux, with psin=1 on the LCFS) is used as the LCFS. If a numerical value is specified for override_psilim, the flux surface with psin=1-override_psilim is used as the LCFS.