Tokamak options

Option	Description	Default
N_norm_prefactor	Prefactor that multiplys ny_total to give the normalization factor for the total number of points in contours. The normalisation factor is used to scale the grid spacing with the total number of points, which keeps the spacing functions consistent when the resolution is changed	1.0
extrapolate_profiles	Use an exponential decay for the pressure outside the separatrix, based on the value and gradient at the plasma edge	False
finecontour_Nfine	Number of points on each FineContour. Increase for more accurate interpolation or distance calculations	100
finecontour_atol	Absolute tolerance for refinement of FineContours	1e-12
finecontour_diagnose	Print and display some information to help diagnose failures in FineContour refinement and adjustment	False
finecontour_extend_prefactor	Prefactor to increase estimate for number of points to extend FineContour when y_boundary_guards>0. May be useful to decrease in case of FineContour creation failures if the target end is very close to a region with problematic psi (e.g. coils, centre column). If the value is too small, may result in extrapolation using FineContour points which is likely to be poorly constrained.	2.0
finecontour_maxits	Maximum number of iterations for refinement and adjustment of a FineContour	200
finecontour_overdamping_factor	Damping factor 0<f<=1 used to stabilise iterations in FineContour.equaliseSpacing. Values towards 0 are most stable but make the smallest updates. Values towards 1 are less stable but potentially faster.	0.8
leg_extend	Extend divertor legs by this length [m]	0.0
leg_extend_lower_inner	Extend lower inner divertor leg	0.0
leg_extend_lower_outer	Extend lower outer divertor leg	0.0
leg_extend_upper_inner	Extend upper inner divertor leg	0.0
leg_extend_upper_outer	Extend upper outer divertor leg	0.0
leg_refine_atol	Tolerance used when iteratively refining the position of start points of legs around an X-point.	1e-05
leg_refine_maxits	Maximum number of iterations for iterative refinement of start points of legs around an X-point.	1000
leg_trace_atol	Tolerance used when calling scipy.integrate.solve_ivp to follow the divertor legs. Default is 0.01*refine_atol.	2e-10
nx_core	Number of radial points in the core	5
nx_inter_sep	Number of radial points in the inter-separatrix region	0
nx_pf	Number of radial points in the PF region Note: Currently can’t be varied due to BOUT++ limitations	5
nx_sol	Number of radial points in the SOL	5
nx_sol_inner	Number of radial points in the outer SOL. Note: Currently can’t be varied due to BOUT++ limitations	5
nx_sol_outer	Number of radial points in the inner SOL. Note: Currently can’t be varied due to BOUT++ limitations	5
ny_inner_divertor	Number of poloidal points in the inner divertor(s)	4
ny_inner_lower_divertor	Number of poloidal points in the inner, lower divertor	4
ny_inner_sol	Number of poloidal points in the inboard SOL upstream of the X-point(s)	4
ny_inner_upper_divertor	Number of poloidal points in the inner, upper divertor	4
ny_outer_divertor	Number of poloidal points in the outer divertor(s)	4
ny_outer_lower_divertor	Number of poloidal points in the outer, lower divertor	4
ny_outer_sol	Number of poloidal points in the outboard SOL upstream of the X-point(s)	4
ny_outer_upper_divertor	Number of poloidal points in the outer, upper divertor	4
ny_sol	Number of poloidal points in the SOL upstream of the X-point(s)	8
orthogonal	Is grid orthogonal?	True
poloidal_spacing_delta_psi	Small increment in psi used to find vector along grad(psi) at end of separatrix segment. Use None for an automatically selected increment.	None
poloidal_spacing_method	Method to use for poloidal spacing function: ‘sqrt’ for getSqrtPoloidalSpacingFunction; ‘monotonic’ for getMonotonicPoloidalDistanceFunc; ‘linear’ for getLinearPoloidalDistanceFunc	sqrt
poloidalfunction_diagnose	Print and plot extra information to diagnose when a poloidal spacing function has an error	False
psi_core	Unnormalised poloidal flux value at the core boundary, used in mesh generation. Overrides psinorm_core if this value is given, if the option is none, then calculated from psinorm_core	None
psi_divide_twopi	Divide poloidal flux, and so poloidal field, by 2pi	False
psi_interpolation_method	Method to use for interpolating psi from the eqdsk file. Possible values are: ‘spline’ for scipy.interpolate.RectBivariateSpline;’dct’ for a discrete cosine transform.	spline
psi_pf_lower	Unnormalised poloidal flux value at the lower PFR boundary, used in mesh generation. Overrides psinorm_pf_lower if this value is given, if the option is none, then calculated from psinorm_pf_lower	None
psi_pf_upper	Unnormalised poloidal flux value at the upper PFR boundary, used in mesh generation. Overrides psinorm_pf_upper if this value is given, if the option is none, then calculated from psinorm_pf_upper	None
psi_sol	Unnormalised poloidal flux value at the SOL boundary, used in mesh generation. Overrides psinorm_sol if this value is given, if the option is none, then calculated from psinorm_sol	None
psi_sol_inner	Unnormalised poloidal flux value at the inner SOL boundary, used in mesh generation. Overrides psinorm_sol_inner if this value is given, if the option is none, then calculated from psinorm_sol_inner	None
psi_spacing_separatrix_multiplier	Factor modifying radial spacing at separatrics: <1 to make points closer, >1 to make points further apart	1.0
psinorm_core	Normalised psi of the inner radial (core) boundary	0.9
psinorm_pf	Normalised psi of the inner radial boundary in the PFR	0.9
psinorm_pf_lower	Normalised psi of the inner radial boundary in the lower PFR	0.9
psinorm_pf_upper	Normalised psi of the inner radial boundary in the upper PFR	0.9
psinorm_sol	Normalised psi of the outer radial (SOL) boundary	1.1
psinorm_sol_inner	Normalised psi of the outer radial boundary in the inner SOL	1.1
refine_atol	Absolute tolerance for refinement of points	2e-08
refine_methods	Ordered list of methods to try when refining points. Valid names are: ‘newton’ - Newton iteration; ‘line’ - a line search; ‘integrate’ integrate along psi gradient; ‘integrate+newton’ integrate, then refine with Newton; ‘none’ - no refinement (always succeeds)	[‘integrate+newton’, ‘integrate’]
refine_timeout	Timeout for refining FineContour objects in seconds. Set to None to disable the timeout; can be useful for debugging as exceptions may get lost due to a separate thread being used to run the refine() method with a timeout. If you get func_timeout.exceptions.FunctionTimedOut exceptions and you are sure there is no problem with the grid, you could try increasing this value.	10.0
refine_width	Width for line search when refining points	1e-05
reverse_Bt	Reverse the sign of toroidal magnetic field Bt.	False
reverse_current	Reverse the sign of the poloidal field	False
sfunc_checktol	Tolerance to check for small negative values that are not significantly different from zero in poloidal spacing functions	1e-13
start_at_upper_outer	Start gridding double-null at upper-outer divertor instead of lower-inner. Warning: this option was added to enable backward compatibility with restart files from simulations in upper-disconnected-double-null configuration using grid files from the IDL hypnotoad; it is not well tested and not recommended to use.	False
target_all_poloidal_spacing_length	Spacing at the wall end of a region (used for orthogonal grids). Use None to not constrain the spacing.	None
target_inner_lower_poloidal_spacing_length	Spacing at the wall end of the inner, lower divertor leg region (used for orthogonal grids). Use None to not constrain the spacing.	None
target_inner_upper_poloidal_spacing_length	Spacing at the wall end of the inner, upper divertor leg region (used for orthogonal grids). Use None to not constrain the spacing. Note an upper single null equilibrium will not use this setting, but rather target_inner_lower_poloidal_spacing_length, for reasons of implementation convenience.	None
target_outer_lower_poloidal_spacing_length	Spacing at the wall end of the outer, lower divertor leg region (used for orthogonal grids). Use None to not constrain the spacing.	None
target_outer_upper_poloidal_spacing_length	Spacing at the wall end of the outer, upper lower divertor leg region (used for orthogonal grids). Use None to not constrain the spacing. Note an upper single null equilibrium will not use this setting, but rather target_outer_lower_poloidal_spacing_length, for reasons of implementation convenience.	None
xpoint_offset	Tolerance for placing intial positions for tracing perpendiculars that should start exactly at an X-point, but initial positions to be slightly displaced from the null so code can follow Grad(psi). This is a numerical fudge factor that may need to be increased for low-resolution input equilibria.	0.1
xpoint_poloidal_spacing_length	Spacing at the X-point end of a region (used for orthogonal grids).	0.05
xpoint_refine_atol	Tolerance used when iteratively refining the position of an X-point that has been identified.	1e-06
xpoint_refine_maxits	Maximum number of iterations for iterative refinement of the position of an X-point that has been identified.	1000
y_boundary_guards	Number of y-boundary cells	0