namespace: castro

AMR

parameter	description	default value
state_interp_order	highest order used in interpolation	1
lin_limit_state_interp	how to do limiting of the state data when interpolating 0: only prevent new extrema 1: preserve linear combinations of state variables 2: preserve linear combinations and prevent new extrema	0
do_reflux	do we do the hyperbolic reflux at coarse-fine interfaces?	1
update_sources_after_reflux	whether to re-compute new-time source terms after a reflux Note: this only works for the CTU and simple-SDC time_integration_method drivers	1
allow_non_unit_aspect_zones	Castro was originally written assuming dx = dy = dz. This assumption is enforced at runtime. Setting allow_non_unit_aspect_zones = 1 opts out.	0

hydrodynamics

parameter	description	default value
difmag	the coefficient of the artificial viscosity	0.1
small_dens	the small density cutoff. Densities below this value will be reset	-1.e200
small_temp	the small temperature cutoff. Temperatures below this value will be reset	-1.e200
small_pres	the small pressure cutoff. Pressures below this value will be reset	-1.e200
small_ener	the small specific internal energy cutoff. Internal energies below this value will be reset	-1.e200
do_hydro	permits hydro to be turned on and off for running pure rad problems	-1
time_integration_method	how do we advance in time? 0 = CTU + Strang, 1 is not used, 2 = SDC, 3 = simplified-SDC	0
limit_fourth_order	do we use a limiter with the fourth-order accurate reconstruction?	1
initialization_is_cell_average	for fourth order, we usually assume that the initialization is done to cell centers and we convert to cell-averages. With this option, we take the initialization as cell- averages (except for T, which we compute to fourth-order through the EOS after initialization).	0
use_reconstructed_gamma1	should we use a reconstructed version of Gamma_1 in the Riemann solver? or the default zone average (requires SDC integration, since we do not trace)	0
add_ext_src	if true, define an additional source term	0
hybrid_hydro	whether to use the hybrid advection scheme that updates z-angular momentum, cylindrical momentum, and azimuthal momentum (3D only)	0
ppm_type	reconstruction type: 0: piecewise linear; 1: classic Colella & Woodward ppm;	1
ppm_do_limiting	do we limit the ppm parabola?	1
mhd_limit_characteristic	For MHD + PLM, do we limit on characteristic or primitive variables	1
ppm_temp_fix	various methods of giving temperature a larger role in the reconstruction—see Zingale & Katz 2015	0
plm_iorder	for piecewise linear, reconstruction order to use 1 = piecewise constant, 2 = piecewise linear	2
plm_limiter	for piecewise linear, what limiter to use? 1 = 2nd order MC, 2 = 4th order MC	2
hybrid_riemann	do we drop from our regular Riemann solver to HLL when we are in shocks to avoid the odd-even decoupling instability?	0
riemann_solver	which Riemann solver do we use: 0: Colella, Glaz, & Ferguson (a two-shock solver); 1: Colella & Glaz (a two- shock solver) 2: HLLC	0
cg_maxiter	for the Colella & Glaz Riemann solver, the maximum number of iterations to take when solving for the star state	12
cg_tol	for the Colella & Glaz Riemann solver, the tolerance to demand in finding the star state	1.0e-5
cg_blend	for the Colella & Glaz Riemann solver, what to do if we do not converge to a solution for the star state. 0 = do nothing; print iterations and exit 1 = revert to the original guess for p-star 2 = do a bisection search for another 2 * cg_maxiter iterations.	2
use_flattening	flatten the reconstructed profiles around shocks to prevent them from becoming too thin	1
transverse_use_eos	after we add the transverse correction to the interface states, replace the predicted pressure with an EOS call (using \(e\) and \(\rho\)).	0
transverse_reset_density	if the transverse interface state correction, if the new density is negative, then replace all of the interface quantities with their values without the transverse correction.	1
transverse_reset_rhoe	if the interface state for \((\rho e)\) is negative after we add the transverse terms, then replace the interface value of \((\rho e)\) with a value constructed from the \((\rho e)\) evolution equation	0
dual_energy_eta1	Threshold value of (E - K) / E such that above eta1, the hydrodynamic pressure is derived from E - K; otherwise, we use the internal energy variable UEINT.	1.0e0
dual_energy_eta2	Threshold value of (E - K) / E such that above eta2, we update the internal energy variable UEINT to match E - K. Below this, UEINT remains unchanged.	1.0e-4
use_pslope	for the piecewise linear reconstruction, do we subtract off \((\rho g)\) from the pressure before limiting? This is a well-balanced method that does well with HSE	0
pslope_cutoff_density	if we are using pslope, below what density to we turn off the well-balanced reconstruction?	-1.e20
limit_fluxes_on_small_dens	Should we limit the density fluxes so that we do not create small densities?	0
speed_limit	Enforce the magnitude of the velocity to be no larger than this number (and optionally limit the fluxes as well). Only applies if it is greater than 0.	0.0
do_sponge	permits sponge to be turned on and off	0
sponge_implicit	if we are using the sponge, whether to use the implicit solve for it	1
ext_src_implicit	if we are using user-defined source terms, are these solved implicitly?	0
source_term_predictor	extrapolate the source terms (gravity and rotation) to \(n+1/2\) timelevel for use in the interface state prediction	0
first_order_hydro	set the flattening parameter to zero to force the reconstructed profiles to be flat, resulting in a first- order method	0
xl_ext_bc_type	if we are doing an external -x boundary condition, who do we interpret it? 1 = HSE	-1
xr_ext_bc_type	if we are doing an external +x boundary condition, who do we interpret it? 1 = HSE	-1
yl_ext_bc_type	if we are doing an external -y boundary condition, who do we interpret it? 1 = HSE	-1
yr_ext_bc_type	if we are doing an external +y boundary condition, who do we interpret it? 1 = HSE	-1
zl_ext_bc_type	if we are doing an external -z boundary condition, who do we interpret it? 1 = HSE	-1
zr_ext_bc_type	if we are doing an external +z boundary condition, who do we interpret it? 1 = HSE	-1
hse_zero_vels	if we are doing HSE boundary conditions, do we zero the velocity?	0
hse_interp_temp	if we are doing HSE boundary conditions, should we get the temperature via interpolation (constant gradient) or hold it constant?	0
hse_fixed_temp	if we are doing HSE boundary conditions and holding the temperature constant, then set it to a fixed value at the boundaries (only if positive)	-1.e200
hse_reflect_vels	if we are doing HSE boundary conditions, how do we treat the velocity? reflect? or outflow?	0
fill_ambient_bc	fills physical domain boundaries with the ambient state	0
ambient_fill_dir	which direction do we do ambient BCs? -1 = all, 0 = x, 1 = y, 2 = z	-1
ambient_outflow_vel	in the ambient region, do we do a basic outflow in the normal direction of the velocity (with a min/max to ensure it is outgoing)	0
clamp_ambient_temp	clamps the ambient material to the ambient temperature	0
ambient_safety_factor	specifies the upper limit, as a multiple of the ambient density, for operations that are applied to ambient material, such as clamping T.	1.1e0
ambient_density	density of the ambient material (should default to the same as small_dens)	-1.e200
ambient_temp	temperature of the ambient material (should default to the same as small_temp)	-1.e200
ambient_energy	energy of the ambient material (should default to the same as small_ener)	-1.e200
sdc_order	integration order for SDC integration valid options are 2 and 4	2
sdc_quadrature	which quadrature type to use with SDC? 0 = Gauss-Lobatto, 1 = Radau	0
sdc_extra	number of extra SDC iterations to take beyond the order. This only applies for true SDC.	0
sdc_solver	which SDC nonlinear solver to use? 1 = Newton, 2 = VODE, 3 = VODE for first iter	1
use_axisymmetric_geom_source	for 2-d axisymmetry, do we include the geometry source terms from Bernand-Champmartin?	1
add_sdc_react_source_to_advection	for simplified-SDC, do we add the reactive source prediction to the interface states used in the advective source construction?	1
hydro_memory_footprint_ratio	In GPU builds, the hydro advance typically results in a large amount of extra temporary memory allocated due to the large tile sizes that are used for computational efficiency. If you want to constrain the code’s GPU memory footprint at the expense of throughput, set the following parameter to some number greater than 0. This controls the ratio of additional extra memory that can be allocated by the hydro relative to the size of the base state (indirectly, by controlling the hydro tile size and then synchronizing each time the amount of currently allocated fab memory reaches the target limit). Choosing a value only slightly larger than 0 means that you want very little additional memory allocated, and you will take a relatively large performance hit, while choosing a value much greater than 1.0 would result in maximum throughput but also maximum memory footprint. You will likely have to experimentally find a good ratio for your use case, but a ratio around 2.0 - 4.0 is likely to yield a reasonable balance between memory footprint and throughput. Note: the first timestep will be very slow when using this option.	-1.0

timestep control

parameter	description	default value
fixed_dt	a fixed timestep to use for all steps (negative turns it off)	-1.0
initial_dt	the initial timestep (negative uses the step returned from the timestep constraints)	-1.0
dt_cutoff	the smallest valid timestep, as a fraction of the current simulation time. if we go below this, we abort.	1.e-12
max_dt	the largest valid timestep—limit all timesteps to be no larger than this	1.e200
cfl	the effective Courant number to use—we will not allow the hydrodynamic waves to cross more than this fraction of a zone over a single timestep	0.8
init_shrink	a factor by which to reduce the first timestep from that requested by the timestep estimators	1.0
change_max	the maximum factor by which the timestep can increase or decrease from one step to the next. Must be greater than 1.0—use max_dt to set a cap on the timestep.	1.1
check_dt_before_advance	whether to check that we will take a valid timestep before the advance	1
check_dt_after_advance	whether to check that we took a valid timestep after the advance	1
plot_per_is_exact	enforce that the AMR plot interval must be hit exactly	0
small_plot_per_is_exact	enforce that the AMR small plot interval must be hit exactly	0
use_retry	Retry a timestep if it violated the timestep-limiting criteria or other checks (negative density, burn failure) over the course of an advance. The criteria will suggest a new timestep that satisfies the criteria, and we will do subcycled timesteps on the same level until we reach the original target time.	1
retry_subcycle_factor	When performing a retry, the factor to multiply the current timestep by when trying again.	0.5
retry_small_density_cutoff	Skip retries for small (or negative) density if the zone’s density prior to the update was below this threshold.	-1.e200
abundance_failure_tolerance	Set the threshold for failing the species abundance validity check.	1.e-2
abundance_failure_rho_cutoff	Do not abort for invalid species abundances if the zone’s density is below this threshold.	-1.e200
use_post_step_regrid	Regrid after every timestep.	0
max_subcycles	Do not permit more subcycled timesteps than this parameter. Set to a negative value to disable this criterion.	10
sdc_iters	Number of iterations for the simplified SDC advance.	2
stopping_criterion_field	Field to use for determining whether to stop the simulation.	“”
stopping_criterion_value	Threshold value for determining whether to stop.	1.e200

reactions

parameter	description	default value
dtnuc_e	Limit the timestep based on how much the burning can change the internal energy of a zone. The timestep is equal to dtnuc \(\cdot\,(e / \dot{e})\).	1.e200
dtnuc_X	Limit the timestep based on how much the burning can change the species mass fractions of a zone. The timestep is equal to dtnuc \(\cdot\,(X / \dot{X})\).	1.e200
dtnuc_X_threshold	If we are using the timestep limiter based on changes in \(X\), set a threshold on the species abundance below which the limiter is not applied. This helps prevent the timestep from becoming very small due to changes in trace species.	1.e-3
do_react	permits reactions to be turned on and off – mostly for efficiency’s sake	-1
react_T_min	minimum temperature for allowing reactions to occur in a zone	0.0
react_T_max	maximum temperature for allowing reactions to occur in a zone	1.e200
react_rho_min	minimum density for allowing reactions to occur in a zone	0.0
react_rho_max	maximum density for allowing reactions to occur in a zone	1.e200
disable_shock_burning	disable burning inside hydrodynamic shock regions note: requires compiling with USE_SHOCK_VAR=TRUE	0
shock_detection_threshold	shock detection threshold for grad{P} / P	0.6666666666666666666666_rt
shock_detection_include_sources	do we subtract off the hydrostatic pressure when evaluating a shock?	1
T_guess	initial guess for the temperature when inverting the EoS (e.g. when calling eos_input_re)	1.e8
drive_initial_convection	if set to 1, we interpolate from the initial model to get the temperature used to call the burner. This prevents reactions from going nonlinear and running away in place before a convective field is established.	0
drive_initial_convection_tmax	maximum time over which to do the drive_initial_convection procedure	1.e200
drive_initial_convection_reinit_period	frequency with which to re-initialize the thermodynamic data while preserving the velocity field during drive_initial_convection	1.e200

diffusion

parameter	description	default value
diffuse_temp	enable thermal diffusion	0
diffuse_cutoff_density	set a cutoff density for diffusion – we zero the term out below this density	-1.e200
diffuse_cutoff_density_hi	secondary cutoff density – there will be a linear dropoff in the diffusion coefficient between this and the primary cutoff density. This should be the larger of the two	-1.e200
diffuse_cond_scale_fac	scaling factor for conductivity	1.0

gravity and rotation

parameter	description	default value
do_grav	permits gravity calculation to be turned on and off	-1
moving_center	to we recompute the center used for the multipole gravity solve each step?	0
grav_source_type	determines how the gravitational source term is added to the momentum and energy state variables.	4
do_rotation	permits rotation calculation to be turned on and off	-1
rotational_period	the rotation period for the corotating frame	-1.e200
rotation_include_centrifugal	permits the centrifugal terms in the rotation to be turned on and off	1
rotation_include_coriolis	permits the Coriolis terms in the rotation to be turned on and off	1
rot_source_type	determines how the rotation source terms are added to the momentum and energy equations	4
implicit_rotation_update	we can do a implicit solution of the rotation update to allow for better coupling of the Coriolis terms	1
rot_axis	the coordinate axis (\(x=1\), \(y=2\), \(z=3\)) for the rotation vector	3
use_point_mass	include a central point mass	0
point_mass	mass of the point mass	0.0
point_mass_fix_solution	if we have a central point mass, we can prevent mass from building up in the zones adjacent to it by keeping their density constant and adding their mass to the point mass object	0
gw_dist	Distance (in kpc) used for calculation of the gravitational wave amplitude (this will be calculated along all three coordinate axes). Only relevant if castro.sum_interval > 0 and if set to a positive number. A standard value in the literature is 10.0 (kpc).	0.0
point_mass_offset_is_true	This integer is used to activate parallel plane 1/r**2 gravity.	0
point_mass_location_offset		0.0

sponge

parameter	description	default value
sponge_lower_radius	Minimum simulation distance from center to start applying the sponge	-1.0
sponge_upper_radius	Simulation distance from the center at which the sponge is fully applied	-1.0
sponge_lower_density	Minimum density at which to start applying the sponge	-1.0
sponge_upper_density	Density at which the sponge is fully applied	-1.0
sponge_lower_pressure	Minimum pressure at which to start applying the sponge	-1.0
sponge_upper_pressure	Pressure at which the sponge is fully applied	-1.0
sponge_lower_factor	Scaling factor for the sponge below the low end	0.0
sponge_upper_factor	Scaling factor for the sponge above the high end	1.0
sponge_target_x_velocity	Target x-velocity for the sponge to drive to	0.0
sponge_target_y_velocity	Target y-velocity for the sponge to drive to	0.0
sponge_target_z_velocity	Target z-velocity for the sponge to drive to	0.0
sponge_timescale	Timescale on which the sponge operates	-1.0

parallelization

parameter	description	default value
bndry_func_thread_safe		1

embiggening

parameter	description	default value
grown_factor	the factor by which to extend the domain upon restart for embiggening	1
star_at_center	used with the embiggening routines to determine how to extend the domain	-1

self-consistent field initialization

parameter	description	default value
do_scf_initial_model	Should we use SCF to construct the initial model?	0
scf_maximum_density	Maximum density on the domain when using SCF	-1.e6
scf_equatorial_radius	Equatorial and polar radii of the star constructed by SCF	-1.e9
scf_polar_radius		-1.e9
scf_relax_tol	SCF relaxation tolerance	1.e-3
scf_max_iterations	Maximum number of SCF iterations	30

refinement

parameter	description	default value
do_special_tagging		0
max_tagging_radius	Maximum radius from the center (in units of the domain width) where tagging is allowed. The default choice implies no restriction.	10.0e0

diagnostics, I/O

parameter	description	default value
v	verbosity level (higher numbers mean more output)	0
dump_old	do we dump the old state into the checkpoint files too?	0
domain_is_plane_parallel	do we assume the domain is plane parallel when computing some of the derived quantities (e.g. radial velocity). Note: this will always assume that the last spatial dimension is vertical	0
print_update_diagnostics	display information about updates to the state (how much mass, momentum, energy added)	(0, 1)
sum_interval	how often (number of coarse timesteps) to compute integral sums (for runtime diagnostics)	-1
sum_per	how often (simulation time) to compute integral sums (for runtime diagnostics)	-1.0e0
job_name	a string describing the simulation that will be copied into the plotfile’s job_info file	“Castro”
output_at_completion	write a final plotfile and checkpoint upon completion	1
reset_checkpoint_time	Do we want to reset the time in the checkpoint? This ONLY takes effect if amr.regrid_on_restart = 1 and amr.checkpoint_on_restart = 1, (which require that max_step and stop_time be less than the value in the checkpoint) and you set it to value greater than this default value.	-1.e200
reset_checkpoint_step	Do we want to reset the number of steps in the checkpoint? This ONLY takes effect if amr.regrid_on_restart = 1 and amr.checkpoint_on_restart = 1, (which require that max_step and stop_time be less than the value in the checkpoint) and you set it to value greater than this default value.	-1
store_omegadot	Do we store the species creation rates in the plotfile? Note, if this option is enabled then more memory will be allocated to hold the results of the burn	0
store_burn_weights	Do we store the burn weights as a diagnostic in the plotfile? Note, if this option is enabled then more memory will be allocated to hold the results of the burn	0
abort_on_invalid_params	Do we abort the run if the inputs file specifies a runtime parameter that we don’t know about? Note: this will only take effect for those namespaces where 100% of the runtime parameters are managed by the python scripts.	0

radiation-hydro

parameter	description	default value
do_radiation	do we enable radiation for a radiation-hydrodynamics run?	-1

particles

parameter	description	default value
do_tracer_particles	permits tracer particle calculation to be turned on and off	0

namespace: diffusion

parameter	description	default value
v	the level of verbosity for the diffusion solve (higher number means more output)	0
mlmg_maxorder	Use MLMG as the operator	4

namespace: gravity

parameter	description	default value
gravity_type	what type	“fillme”
const_grav	if doing constant gravity, what is the acceleration	0.0
direct_sum_bcs	Check if the user wants to compute the boundary conditions using the brute force method. Default is false, since this method is slow.	0
drdxfac	ratio of dr for monopole gravity binning to grid resolution	1
max_multipole_order	the maximum mulitpole order to use for multipole BCs when doing Poisson gravity	0
v	the level of verbosity for the gravity solve (higher number means more output on the status of the solve / multigrid	0
no_sync	do we perform the synchronization at coarse-fine interfaces?	0
do_composite_phi_correction	should we apply a lagged correction to the potential that gets us closer to the composite solution? This makes the resulting fine grid calculation slightly more accurate, at the cost of an additional Poisson solve per timestep.	1
max_solve_level	For all gravity types, we can choose a maximum level for explicitly calculating the gravity and associated potential. Above that level, we interpolate from coarser levels.	MAX_LEV-1
get_g_from_phi	For non-Poisson gravity, do we want to construct the gravitational acceleration by taking the gradient of the potential, rather than constructing it directly?	0
mlmg_max_fmg_iter	how many FMG cycles?	0
mlmg_agglomeration	Do agglomeration?	1
mlmg_consolidation		1
mlmg_nsolve	Do N-Solve?	0

namespace: particles

parameter	description	default value
v	the level of verbosity for the tracer particle (0 or 1)	0
particle_init_file	the name of an input file containing the total particle number and the initial position of each particle.	“”
particle_restart_file	the name of a file with new particles at restart	“”
restart_from_nonparticle_chkfile	to restart from a checkpoint that was written with USE_PARTICLES =FALSE	0
particle_output_file	the name of timestamp files.	“”
timestamp_dir	the name of a directory in which timestamp files are stored.	“”
timestamp_density	whether the local densities at given positions of particles are stored in output files	1
timestamp_temperature	whether the local temperatures at given positions of particles are stored in output files	0

namespace: radiation

parameter	description	default value
prop_temp_floor		0.0
flatten_pp_threshold		-1.0
comoving	are we in a comoving reference frame?	1
closure	which closure relation to use 0: f = lambda 1: f = 1/3 2: f = 1 - 2 * lambda 3: f = lambda + (lambda * R)^2 4: f = 1/3 + 2/3 (lambda * R)^2	3
limiter	which limiter to use 0: no limiter 2: Lev-Pom limiter 12: Bruenn 22: square root 32: Minerbo	2
fspace_advection_type	frequency space advection type	2
plot_lambda	do we plot the flux limiter lambda?	0
plot_kappa_p	do we plot the Planck mean opacity?	0
plot_kappa_r	do we plot the Rosseland mean opacity?	0
plot_lab_Er	do we plot the lab radiation energy?	0
plot_lab_flux	do we plot the lab radiation flux?	0
plot_com_flux	do we plot the comoving frame radiation flux?	0

namespace: radsolve

parameter	description	default value
level_solver_flag	the linear solver option to use	1
use_hypre_nonsymmetric_terms		0
reltol		1.e-10
abstol		1.e-10
maxiter		40
alpha		1.0
beta		1.0
v		0