# openmc.deplete.helpers.ConstantFissionYieldHelper¶

class openmc.deplete.helpers.ConstantFissionYieldHelper(chain_nuclides, energy=0.0253)[source]

Class that uses a single set of fission yields on each isotope

Parameters: chain_nuclides (iterable of openmc.deplete.Nuclide) – Nuclides tracked in the depletion chain. All nuclides are not required to have fission yield data. energy (float, optional) – Key in openmc.deplete.Nuclide.yield_data corresponding to the desired set of fission yield data. Typically one of {0.0253, 500000, 14000000} corresponding to 0.0253 eV, 500 keV, and 14 MeV yield libraries. If the specific key is not found, will fall back to closest energy present. Default: 0.0253 eV for thermal yields constant_yields (collections.defaultdict) – Fission yields for all nuclides that only have one set of fission yield data. Dictionary of form {str: {str: float}} representing yields for {parent: {product: yield}}. Default return object is an empty dictionary energy (float) – Energy of fission yield libraries.
classmethod from_operator(operator, **kwargs)[source]

Return a new ConstantFissionYieldHelper using operator data

All keyword arguments should be identical to their counterpart in the main __init__ method

Parameters: operator (openmc.deplete.TransportOperator) – operator with a depletion chain kwargs – Additional keyword arguments to be used in construction ConstantFissionYieldHelper
weighted_yields(_local_mat_index=None)[source]

Return fission yields for all nuclides requested

Parameters: _local_mat_index (int, optional) – Current material index. Not used since all yields are constant library – Dictionary of {parent: {product: fyield}} collections.defaultdict