def test_readwrite():
"""Test reading/writing to a file round-trip"""
tokamak = freegs.machine.MAST_sym()
eq = freegs.Equilibrium(
tokamak=tokamak,
Rmin=0.1,
Rmax=2.0,
Zmin=-1.0,
Zmax=1.0,
nx=17,
ny=17,
boundary=freegs.boundary.freeBoundaryHagenow,
)
profiles = freegs.jtor.ConstrainPaxisIp(1e4, 1e6, 2.0)
# Note here the X-point locations and isoflux locations are not the same.
# The result will be an unbalanced double null configuration, where the
# X-points are on different flux surfaces.
xpoints = [(1.1, -0.6), (1.1, 0.8)]
isoflux = [(1.1, -0.6, 1.1, 0.6)]
constrain = freegs.control.constrain(xpoints=xpoints, isoflux=isoflux)
freegs.solve(eq, profiles, constrain, maxits=25, atol=1e-3, rtol=1e-1)
memory_file = io.BytesIO()
with freegs.OutputFile(memory_file, "w") as f:
f.write_equilibrium(eq)
with freegs.OutputFile(memory_file, "r") as f:
read_eq = f.read_equilibrium()
assert tokamak == read_eq.tokamak
assert allclose(eq.psi(), read_eq.psi())
#!/usr/bin/env python
import freegs
#########################################
# Create the machine, which specifies coil locations
# and equilibrium, specifying the domain to solve over
tokamak = freegs.machine.TestTokamak()
eq = freegs.Equilibrium(tokamak=tokamak,
Rmin=0.1, Rmax=2.0, # Radial domain
Zmin=-1.0, Zmax=1.0, # Height range
nx=65, ny=65, # Number of grid points
boundary=freegs.boundary.freeBoundaryHagenow) # Boundary condition
#########################################
# Plasma profiles
profiles = freegs.jtor.ConstrainPaxisIp(1e3, # Plasma pressure on axis [Pascals]
2e5, # Plasma current [Amps]
2.0) # Vacuum f=R*Bt
#########################################
# Coil current constraints
#
# Specify locations of the X-points
# to use to constrain coil currents
xpoints = [(1.1, -0.6), # (R,Z) locations of X-points
start_resolution = 17
nrefinements = 5 # Number of refinements. Minimum 2
rtol = 1e-10 # Relative tolerance in Picard iteration
location = (1.2, 0.1) # Location to record values at
############################################
# Generate low resolution solution
tokamak = freegs.machine.TestTokamak()
eq = freegs.Equilibrium(
tokamak=tokamak,
Rmin=0.1,
Rmax=2.0, # Radial domain
Zmin=-1.0,
Zmax=1.0, # Height range
nx=start_resolution,
ny=start_resolution, # Number of grid points
boundary=freegs.boundary.freeBoundaryHagenow)
profiles = freegs.jtor.ConstrainPaxisIp(
1e3, # Plasma pressure on axis [Pascals]
2e5, # Plasma current [Amps]
2.0) # Vacuum f=R*Bt
xpoints = [
(1.1, -0.6), # (R,Z) locations of X-points
(1.1, 0.8)
]
# Plasma equilibrium (Grad-Shafranov) solver
import freegs
# Boundary conditions
import freegs.boundary as boundary
profiles = freegs.jtor.ConstrainPaxisIp(
1e4, # Plasma pressure on axis [Pascals]
1e6, # Plasma current [Amps]
1.0) # fvac = R*Bt
eq = freegs.Equilibrium(Rmin=0.1,
Rmax=2.0,
Zmin=-1.0,
Zmax=1.0,
nx=65,
ny=65,
boundary=boundary.fixedBoundary)
# Nonlinear solver for Grad-Shafranov equation
freegs.solve(
eq, # The equilibrium to adjust
profiles) # The toroidal current profile function
print("Done!")
# Plot equilibrium
from freegs.plotting import plotEquilibrium
plotEquilibrium(eq)
#!/usr/bin/env python
import freegs
#########################################
# Create the machine, which specifies coil locations
# and equilibrium, specifying the domain to solve over
tokamak = freegs.machine.MAST()
eq = freegs.Equilibrium(
tokamak=tokamak,
Rmin=0.1,
Rmax=2.0, # Radial domain
Zmin=-2.0,
Zmax=2.0, # Height range
nx=65,
ny=65) # Number of grid points
#########################################
# Plasma profiles
profiles = freegs.jtor.ConstrainPaxisIp(
3e3, # Plasma pressure on axis [Pascals]
7e5, # Plasma current [Amps]
0.4) # vacuum f = R*Bt
#########################################
# Coil current constraints
#
# Specify locations of the X-points
#!/usr/bin/env python
#
# Example demonstrating functions for creating and finding X-points
import freegs
# Plotting routines
from freegs.plotting import plotEquilibrium, plotCoils, plotConstraints
import matplotlib.pyplot as plt
tokamak = freegs.machine.TestTokamak()
eq = freegs.Equilibrium(tokamak=tokamak, nx=256,ny=256)
##########################################################
# Calculate currents in coils to create X-points
# in specified locations
#
xpoints = [(1.1, -0.8), # (R,Z) locations of X-points
(1.1, 0.8)]
control = freegs.control.constrain(xpoints=xpoints)
control(eq) # Apply control to Equilibrium eq
psi = eq.psi()
print("=> Solved coil currents, created X-points")
ax = plotEquilibrium(eq, show=False)
plotCoils(tokamak.coils, axis=ax)
profiles = freegs.jtor.ConstrainBetapIp(0.1, 1e6, 1.0)
resolutions = [33, 65, 129, 257, 513] #, 1025]
boundaries = [("A", 0.1, 2.0, -1.0, 1.0), ("B", 0.5, 1.75, -0.8, 1.1)]
for n in resolutions:
for bndry_name, Rmin, Rmax, Zmin, Zmax in boundaries:
# Re-create objects so no state is retained between runs
tokamak = freegs.machine.TestTokamak()
eq = freegs.Equilibrium(
tokamak=tokamak,
Rmin=Rmin,
Rmax=Rmax, # Radial domain
Zmin=Zmin,
Zmax=Zmax, # Height range
nx=n,
ny=n) # Number of grid points
freegs.solve(
eq, # The equilibrium to adjust
profiles, # The toroidal current profile function
constrain, # Constraint function to set coil currents
rtol=1e-6,
show=False)
# Save solution for later analysis
with open("test-02-" + bndry_name + "-" + str(n) + ".pkl", "wb") as f:
pickle.dump(n, f)
pickle.dump((bndry_name, Rmin, Rmax, Zmin, Zmax), f)
