openmc.data.MadlandNix¶
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class
openmc.data.
MadlandNix
(efl, efh, tm)[source]¶ Energy-dependent fission neutron spectrum (Madland and Nix) given in ENDF MF=5, LF=12 represented as
\[f(E \rightarrow E') = \frac{1}{2} [ g(E', E_F(L)) + g(E', E_F(H))]\]where
\[\begin{split}g(E',E_F) = \frac{1}{3\sqrt{E_F T_M}} \left [ u_2^{3/2} E_1 (u_2) - u_1^{3/2} E_1 (u_1) + \gamma \left ( \frac{3}{2}, u_2 \right ) - \gamma \left ( \frac{3}{2}, u_1 \right ) \right ] \\ u_1 = \left ( \sqrt{E'} - \sqrt{E_F} \right )^2 / T_M \\ u_2 = \left ( \sqrt{E'} + \sqrt{E_F} \right )^2 / T_M.\end{split}\]Parameters: - efh (efl,) – Constants which represent the average kinetic energy per nucleon of the fission fragment (efl = light, efh = heavy)
- tm (openmc.data.Tabulated1D) – Parameter tabulated as a function of incident neutron energy
Variables: - efh (efl,) – Constants which represent the average kinetic energy per nucleon of the fission fragment (efl = light, efh = heavy)
- tm (openmc.data.Tabulated1D) – Parameter tabulated as a function of incident neutron energy
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classmethod
from_endf
(file_obj, params)[source]¶ Generate Madland-Nix fission spectrum from an ENDF evaluation
Parameters: - file_obj (file-like object) – ENDF file positioned at the start of a section for an energy distribution.
- params (list) – List of parameters at the start of the energy distribution that includes the LF value indicating what type of energy distribution is present.
Returns: Madland-Nix fission spectrum
Return type:
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classmethod
from_hdf5
(group)[source]¶ Generate Madland-Nix fission spectrum from HDF5 data
Parameters: group (h5py.Group) – HDF5 group to read from Returns: Madland-Nix fission spectrum Return type: openmc.data.MadlandNix