openmc.data.WindowedMultipole

class openmc.data.WindowedMultipole(name)[source]

Resonant cross sections represented in the windowed multipole format.

Parameters:

name (str) – Name of the nuclide using the GND naming convention
Variables:
  • name (str) – Name of the nuclide using the GND naming convention
  • spacing (float) – The width of each window in sqrt(E)-space. For example, the frst window will end at (sqrt(E_min) + spacing)**2 and the second window at (sqrt(E_min) + 2*spacing)**2.
  • sqrtAWR (float) – Square root of the atomic weight ratio of the target nuclide.
  • E_min (float) – Lowest energy in eV the library is valid for.
  • E_max (float) – Highest energy in eV the library is valid for.
  • data (np.ndarray) – A 2D array of complex poles and residues. data[i, 0] gives the energy at which pole i is located. data[i, 1:] gives the residues associated with the i-th pole. There are 3 residues, one each for the scattering, absorption, and fission channels.
  • windows (np.ndarray) – A 2D array of Integral values. windows[i, 0] - 1 is the index of the first pole in window i. windows[i, 1] - 1 is the index of the last pole in window i.
  • broaden_poly (np.ndarray) – A 1D array of boolean values indicating whether or not the polynomial curvefit in that window should be Doppler broadened.
  • curvefit (np.ndarray) – A 3D array of Real curvefit polynomial coefficients. curvefit[i, 0, :] gives coefficients for the scattering cross section in window i. curvefit[i, 1, :] gives absorption coefficients and curvefit[i, 2, :] gives fission coefficients. The polynomial terms are increasing powers of sqrt(E) starting with 1/E e.g: a/E + b/sqrt(E) + c + d sqrt(E) + …
export_to_hdf5(path, mode='a', libver='earliest')[source]

Export windowed multipole data to an HDF5 file.

Parameters:
  • path (str) – Path to write HDF5 file to
  • mode ({'r+', 'w', 'x', 'a'}) – Mode that is used to open the HDF5 file. This is the second argument to the h5py.File constructor.
  • libver ({'earliest', 'latest'}) – Compatibility mode for the HDF5 file. ‘latest’ will produce files that are less backwards compatible but have performance benefits.
classmethod from_endf(endf_file, log=False, vf_options=None, wmp_options=None)[source]

Generate windowed multipole neutron data from an ENDF evaluation.

New in version 0.12.1.

Parameters:
  • endf_file (str) – Path to ENDF evaluation
  • log (bool or int, optional) – Whether to print running logs (use int for verbosity control)
  • vf_options (dict, optional) – Dictionary of keyword arguments, e.g. {‘njoy_error’: 0.001}, passed to openmc.data.multipole.vectfit_nuclide()
  • wmp_options (dict, optional) – Dictionary of keyword arguments, e.g. {‘search’: True, ‘rtol’: 0.01}, passed to openmc.data.WindowedMultipole.from_multipole()
Returns:

Resonant cross sections represented in the windowed multipole format.
Return type:

openmc.data.WindowedMultipole
classmethod from_hdf5(group_or_filename)[source]

Construct a WindowedMultipole object from an HDF5 group or file.

Parameters:group_or_filename (h5py.Group or str) – HDF5 group containing multipole data. If given as a string, it is assumed to be the filename for the HDF5 file, and the first group is used to read from.
Returns:Resonant cross sections represented in the windowed multipole format.
Return type:openmc.data.WindowedMultipole
classmethod from_multipole(mp_data, search=None, log=False, **kwargs)[source]

Generate windowed multipole neutron data from multipole data.

Parameters:
  • mp_data (dictionary or str) – Dictionary or Path to the multipole data stored in a pickle file
  • search (bool, optional) – Whether to search for optimal window size and curvefit order. Defaults to True if no windowing parameters are specified.
  • log (bool or int, optional) – Whether to print running logs (use int for verbosity control)
  • **kwargs – Keyword arguments passed to openmc.data.multipole._windowing()
Returns:

Resonant cross sections represented in the windowed multipole format.
Return type:

openmc.data.WindowedMultipole