Solver modes

Mode	Description
full_system	CVODE on the full state vector, with a dense, banded, GMRES or KLU sparse-direct linear solver
active_window	two independent sliding windows, one over SIA size and one over vacancy size, with an OpenMP-parallel right-hand side

In the active_window mode the number of threads is selected from the sweep length of the right-hand side, and it can be set with the environment variable OMP_NUM_THREADS. The same code path runs on one thread when OpenMP is not available.

Physics options

The physics is selected by two independent choices.

Choice	Values	Meaning
equations	discrete or bin_moment	one ODE per size, or the logarithmic bin-moment grouping
cascade	fission or fusion	the cascade spectrum and the helium reduction

The four combinations map to the strings that are used on disk:

equations	cascade	physics_option
discrete	fission	full_CD_fission
discrete	fusion	full_CD_fusion
bin_moment	fission	bin_moment_CD_fission
bin_moment	fusion	bin_moment_CD_fusion

The constructor of RadClusterSimulation accepts either form. The functions make_physics_option() and split_physics_option() convert between them.

Linear solvers

linsol	Linear solver
dense	dense direct
band	banded direct
gmres	GMRES, with the Jacobi or the Woodbury preconditioner
klu	KLU sparse direct, with a colored finite-difference Jacobian. Discrete equations only

Adaptive size domain

The method run_adaptive() of RadClusterSimulation expands the tracked cluster-size domain when the distribution reaches the top of the grid. The method run() integrates on a fixed domain.

See also: Woodbury preconditioner, State-space reductions