A nuclear reaction

A Reaction object represents a single reaction channel for a nuclide with an associated cross section and, if present, a secondary angle and energy distribution.


mt (int) – The ENDF MT number for this reaction.

  • center_of_mass (bool) – Indicates whether scattering kinematics should be performed in the center-of-mass or laboratory reference frame. grid above the threshold value in barns.
  • mt (int) – The ENDF MT number for this reaction.
  • q_value (float) – The Q-value of this reaction in eV.
  • xs (dict of str to – Microscopic cross section for this reaction as a function of incident energy; these cross sections are provided in a dictionary where the key is the temperature of the cross section set.
  • products (Iterable of – Reaction products
  • derived_products (Iterable of – Derived reaction products. Used for ‘total’ fission neutron data when prompt/delayed data also exists.
classmethod from_endf(ev, mt)[source]

Generate a reaction from an ENDF evaluation


rx – Reaction data

Return type:

classmethod from_hdf5(group, energy)[source]

Generate reaction from an HDF5 group

  • group (h5py.Group) – HDF5 group to read from
  • energy (dict) – Dictionary whose keys are temperatures (e.g., ‘300K’) and values are arrays of energies at which cross sections are tabulated at.

Reaction data

Return type:


Write reaction to an HDF5 group

Parameters:group (h5py.Group) – HDF5 group to write to