import numpy as np
from .angle_energy import AngleEnergy
from .correlated import CorrelatedAngleEnergy
[docs]class CoherentElasticAE(AngleEnergy):
r"""Differential cross section for coherent elastic scattering
The differential cross section for coherent elastic scattering from a
powdered crystalline material may be represented as:
.. math::
\frac{d^2\sigma}{dE'd\Omega} (E\rightarrow E',\mu,T) = \frac{1}{E} \sum
\limits_{i=1}^{E_i < E} s_i(T) \delta(\mu - \mu_i) \delta (E - E')
/(2\pi)
where :math:`E_i` are the energies of the Bragg edges in [eV], :math:`s_i(T)`
is the structure factor in [eV-b] at the moderator temperature :math:`T`
in [K], and :math:`\mu_i = 1 - 2E_i/E`.
Parameters
----------
coherent_xs : openmc.data.CoherentElastic
Coherent elastic scattering cross section
Attributes
----------
coherent_xs : openmc.data.CoherentElastic
Coherent elastic scattering cross section
"""
def __init__(self, coherent_xs):
self.coherent_xs = coherent_xs
[docs] def to_hdf5(self, group):
"""Write coherent elastic distribution to an HDF5 group
Parameters
----------
group : h5py.Group
HDF5 group to write to
"""
group.attrs['type'] = np.string_('coherent_elastic')
group['coherent_xs'] = group.parent['xs']
[docs]class IncoherentElasticAE(AngleEnergy):
r"""Differential cross section for incoherent elastic scattering
The differential cross section for incoherent elastic scattering may be
represented as:
.. math::
\frac{d^2\sigma}{dE'd\Omega} (E\rightarrow E',\mu,T) = \frac{\sigma_b}
{4\pi} e^{-2EW'(T)(1-\mu)} \delta(E - E')
where :math:`\sigma_b` is the characteristic cross section in [b] and
:math:`W'(T)` is the Debye-Waller integral divided by the atomic mass in
[eV\ :math:`^{-1}`].
Parameters
----------
debye_waller : float
Debye-Waller integral in [eV\ :math:`^{-1}`]
Attributes
----------
debye_waller : float
Debye-Waller integral in [eV\ :math:`^{-1}`]
"""
def __init__(self, debye_waller):
self.debye_waller = debye_waller
[docs] def to_hdf5(self, group):
"""Write incoherent elastic distribution to an HDF5 group
Parameters
----------
group : h5py.Group
HDF5 group to write to
"""
group.attrs['type'] = np.string_('incoherent_elastic')
group.create_dataset('debye_waller', data=self.debye_waller)
[docs] @classmethod
def from_hdf5(cls, group):
"""Generate incoherent elastic distribution from HDF5 data
Parameters
----------
group : h5py.Group
HDF5 group to read from
Returns
-------
openmc.data.IncoherentElasticAE
Incoherent elastic distribution
"""
return cls(group['debye_waller'])
[docs]class IncoherentElasticAEDiscrete(AngleEnergy):
"""Discrete angle representation of incoherent elastic scattering
Parameters
----------
mu_out : numpy.ndarray
Equi-probable discrete angles at each incoming energy
"""
def __init__(self, mu_out):
self.mu_out = mu_out
[docs] def to_hdf5(self, group):
"""Write discrete incoherent elastic distribution to an HDF5 group
Parameters
----------
group : h5py.Group
HDF5 group to write to
"""
group.attrs['type'] = np.string_('incoherent_elastic_discrete')
group.create_dataset('mu_out', data=self.mu_out)
[docs] @classmethod
def from_hdf5(cls, group):
"""Generate discrete incoherent elastic distribution from HDF5 data
Parameters
----------
group : h5py.Group
HDF5 group to read from
Returns
-------
openmc.data.IncoherentElasticAEDiscrete
Discrete incoherent elastic distribution
"""
return cls(group['mu_out'][()])
[docs]class IncoherentInelasticAEDiscrete(AngleEnergy):
"""Discrete angle representation of incoherent inelastic scattering
Parameters
----------
energy_out : numpy.ndarray
Outgoing energies for each incoming energy
mu_out : numpy.ndarray
Discrete angles for each incoming/outgoing energy
skewed : bool
Whether discrete angles are equi-probable or have a skewed distribution
Attributes
----------
energy_out : numpy.ndarray
Outgoing energies for each incoming energy
mu_out : numpy.ndarray
Discrete angles for each incoming/outgoing energy
skewed : bool
Whether discrete angles are equi-probable or have a skewed distribution
"""
def __init__(self, energy_out, mu_out, skewed=False):
self.energy_out = energy_out
self.mu_out = mu_out
self.skewed = skewed
[docs] def to_hdf5(self, group):
"""Write discrete incoherent inelastic distribution to an HDF5 group
Parameters
----------
group : h5py.Group
HDF5 group to write to
"""
group.attrs['type'] = np.string_('incoherent_inelastic_discrete')
group.create_dataset('energy_out', data=self.energy_out)
group.create_dataset('mu_out', data=self.mu_out)
group.create_dataset('skewed', data=self.skewed)
[docs] @classmethod
def from_hdf5(cls, group):
"""Generate discrete incoherent inelastic distribution from HDF5 data
Parameters
----------
group : h5py.Group
HDF5 group to read from
Returns
-------
openmc.data.IncoherentInelasticAEDiscrete
Discrete incoherent inelastic distribution
"""
energy_out = group['energy_out'][()]
mu_out = group['mu_out'][()]
skewed = bool(group['skewed'])
return cls(energy_out, mu_out, skewed)
class IncoherentInelasticAE(CorrelatedAngleEnergy):
_name = 'incoherent_inelastic'