import freegs
from freegs import geqdsk
from freegs.equilibrium import refine
from freegs.plotting import plotEquilibrium
# Reading MAST equilibrium, up-down symmetric coils
tokamak = freegs.machine.MAST()
#with open("g014220.00200") as f:
with open("mast.geqdsk") as f:
eq = geqdsk.read(f, tokamak, show=True)
# Increase resolution by a factor of 2
eq2 = refine(eq)
# Re-solve, keeping the same control points and profiles
freegs.solve(eq2, eq._profiles, eq.control, rtol=1e-6)
# Save to G-EQDSK
with open("mast-highres.geqdsk", "w") as f:
geqdsk.write(eq2, f)
plotEquilibrium(eq2)
#########################################
# Nonlinear solve
freegs.solve(
eq, # The equilibrium to adjust
profiles, # The toroidal current profile function
constrain) # Constraint function to set coil currents
# eq now contains the solution
print("Done!")
print("Plasma current: %e Amps" % (eq.plasmaCurrent()))
print("Plasma pressure on axis: %e Pascals" % (eq.pressure(0.0)))
tokamak.printCurrents()
##############################################
# Save to G-EQDSK file
from freegs import geqdsk
with open("lsn.geqdsk", "w") as f:
geqdsk.write(eq, f)
##############################################
# Final plot
axis = eq.plot(show=False)
constrain.plot(axis=axis, show=True)