%ITER Card

This card can be used to control the iterations in KOMODO calculations. You may use this if the default iteration parameters lead to calculation instability.

%ITER	Variable	Description	Remarks
LINE 1	NOUT	Maximum number of outer iteration	Default = 500. Not used if %THER card active
	NIN	Maximum number of inner iteration per an outer iteration	Default = 2
	SERC	Fission source error criteria (relative error)	Default = 1.e-5
	FERC	Flux error criteria (relative error)	Default = 1.e-5
	NAC	Outer iteration fission source extrapolation interval	Default = 5
	NUPD	Nodal update interval through outer iteration	Default = (NX+NY+NZ)/2.5. Effective only for ANM and PNM nodal kernel
	TH_NITER	Maximum number of T-H iteration	Default = 30. Effective only if %THER is active and if the calculation mode is NOT BCSEARCH
	NTH	Maximum number of outer iteration per T-H iteration	Default = 20. Effective only if %THER card active

Note: TH iteration is non-linear iteration to determine TH parameters

Example:

! Iteration control card
%ITER
1200 3 1.e-5 1.e-5 25 40 20 80

What we have done here is:

1. Set maximum number of outer iteration = 1200
2. Set maximum number of inner iteration = 3
3. Set fission source error criteria = 1.e-5
4. Set flux error criteria = 1.e-5
5. Set fission source extrapolation interval every 25 outer iterations
6. Set nodal update interval every 40 outer iterations
7. Set maximum number of TH iterations = 20
8. Set maximum number outer iterations for each TH iteration is 80