Abstract class for obtaining normalization factor on tallies

This helper class determines how reaction rates calculated by an instance of should be normalized for the purpose of constructing a burnup matrix. Based on the method chosen, the power or source rate provided by the user, and reaction rates from a ReactionRateHelper, this class will scale reaction rates to the correct values.


nuclides (list of str) – All nuclides with desired reaction rates. Ordered to be consistent with

abstract factor(source_rate)[source]

Return normalization factor


source_rate (float) – Power in [W] or source rate in [neutron/sec]


Normalization factor for tallies

Return type


property nuclides

List of nuclides with requested reaction rates

abstract prepare(chain_nucs, rate_index)[source]

Perform work needed to obtain energy produced

This method is called prior to calculating the reaction rates in Only used for energy-based normalization.

  • chain_nucs (list of str) – All nuclides to be tracked in this problem

  • rate_index (dict of str to int) – Mapping from nuclide name to index in the fission_rates for update().


Reset state for normalization


Update the normalization based on fission rates (only used for energy-based normalization)


fission_rates (numpy.ndarray) – fission reaction rate for each isotope in the specified material. Should be ordered corresponding to initial rate_index used in prepare()