openmc.data.WindowedMultipole

class openmc.data.WindowedMultipole[source]

Resonant cross sections represented in the windowed multipole format.

Variables:
  • num_l (Integral) – Number of possible l quantum states for this nuclide.
  • fit_order (Integral) – Order of the windowed curvefit.
  • fissionable (bool) – Whether or not the target nuclide has fission data.
  • formalism ({'MLBW', 'RM'}) – The R-matrix formalism used to reconstruct resonances. Either ‘MLBW’ for multi-level Breit Wigner or ‘RM’ for Reich-Moore.
  • spacing (Real) – The width of each window in sqrt(E)-space. For example, the frst window will end at (sqrt(start_E) + spacing)**2 and the second window at (sqrt(start_E) + 2*spacing)**2.
  • sqrtAWR (Real) – Square root of the atomic weight ratio of the target nuclide.
  • start_E (Real) – Lowest energy in eV the library is valid for.
  • end_E (Real) – 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 for Reich-Moore data, one each for the total, absorption, and fission channels. Multi-level Breit Wigner data has an additional residue for the competitive channel.
  • pseudo_k0RS (np.ndarray) – A 1D array of Real values. There is one value for each valid l quantum number. The values are equal to sqrt(2 m / hbar) * AWR / (AWR + 1) * r where m is the neutron mass, AWR is the atomic weight ratio, and r is the l-dependent scattering radius.
  • l_value (np.ndarray) – A 1D array of Integral values equal to the l quantum number for each pole + 1.
  • w_start (np.ndarray) – A 1D array of Integral values. w_start[i] - 1 is the index of the first pole in window i.
  • w_end (np.ndarray) – A 1D array of Integral values. w_end[i] - 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 total 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) + ...
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