from collections.abc import Iterable
from numbers import Integral, Real
import numpy as np
import openmc.checkvalue as cv
from openmc.mixin import EqualityMixin
from .data import EV_PER_MEV
[docs]class ProbabilityTables(EqualityMixin):
r"""Unresolved resonance region probability tables.
Parameters
----------
energy : Iterable of float
Energies in eV at which probability tables exist
table : numpy.ndarray
Probability tables for each energy. This array is of shape (N, 6, M)
where N is the number of energies and M is the number of bands. The
second dimension indicates whether the value is for the cumulative
probability (0), total (1), elastic (2), fission (3), :math:`(n,\gamma)`
(4), or heating number (5).
interpolation : {2, 5}
Interpolation scheme between tables
inelastic_flag : int
A value less than zero indicates that the inelastic cross section is
zero within the unresolved energy range. A value greater than zero
indicates the MT number for a reaction whose cross section is to be used
in the unresolved range.
absorption_flag : int
A value less than zero indicates that the "other absorption" cross
section is zero within the unresolved energy range. A value greater than
zero indicates the MT number for a reaction whose cross section is to be
used in the unresolved range.
multiply_smooth : bool
Indicate whether probability table values are cross sections (False) or
whether they must be multiply by the corresponding "smooth" cross
sections (True).
Attributes
----------
energy : Iterable of float
Energies in eV at which probability tables exist
table : numpy.ndarray
Probability tables for each energy. This array is of shape (N, 6, M)
where N is the number of energies and M is the number of bands. The
second dimension indicates whether the value is for the cumulative
probability (0), total (1), elastic (2), fission (3), :math:`(n,\gamma)`
(4), or heating number (5).
interpolation : {2, 5}
Interpolation scheme between tables
inelastic_flag : int
A value less than zero indicates that the inelastic cross section is
zero within the unresolved energy range. A value greater than zero
indicates the MT number for a reaction whose cross section is to be used
in the unresolved range.
absorption_flag : int
A value less than zero indicates that the "other absorption" cross
section is zero within the unresolved energy range. A value greater than
zero indicates the MT number for a reaction whose cross section is to be
used in the unresolved range.
multiply_smooth : bool
Indicate whether probability table values are cross sections (False) or
whether they must be multiply by the corresponding "smooth" cross
sections (True).
"""
def __init__(self, energy, table, interpolation, inelastic_flag=-1,
absorption_flag=-1, multiply_smooth=False):
self.energy = energy
self.table = table
self.interpolation = interpolation
self.inelastic_flag = inelastic_flag
self.absorption_flag = absorption_flag
self.multiply_smooth = multiply_smooth
@property
def absorption_flag(self):
return self._absorption_flag
@property
def energy(self):
return self._energy
@property
def inelastic_flag(self):
return self._inelastic_flag
@property
def interpolation(self):
return self._interpolation
@property
def multiply_smooth(self):
return self._multiply_smooth
@property
def table(self):
return self._table
@absorption_flag.setter
def absorption_flag(self, absorption_flag):
cv.check_type('absorption flag', absorption_flag, Integral)
self._absorption_flag = absorption_flag
@energy.setter
def energy(self, energy):
cv.check_type('probability table energies', energy, Iterable, Real)
self._energy = energy
@inelastic_flag.setter
def inelastic_flag(self, inelastic_flag):
cv.check_type('inelastic flag', inelastic_flag, Integral)
self._inelastic_flag = inelastic_flag
@interpolation.setter
def interpolation(self, interpolation):
cv.check_value('interpolation', interpolation, [2, 5])
self._interpolation = interpolation
@multiply_smooth.setter
def multiply_smooth(self, multiply_smooth):
cv.check_type('multiply by smooth', multiply_smooth, bool)
self._multiply_smooth = multiply_smooth
@table.setter
def table(self, table):
cv.check_type('probability tables', table, np.ndarray)
self._table = table
[docs] def to_hdf5(self, group):
"""Write probability tables to an HDF5 group
Parameters
----------
group : h5py.Group
HDF5 group to write to
"""
group.attrs['interpolation'] = self.interpolation
group.attrs['inelastic'] = self.inelastic_flag
group.attrs['absorption'] = self.absorption_flag
group.attrs['multiply_smooth'] = int(self.multiply_smooth)
group.create_dataset('energy', data=self.energy)
group.create_dataset('table', data=self.table)
[docs] @classmethod
def from_hdf5(cls, group):
"""Generate probability tables from HDF5 data
Parameters
----------
group : h5py.Group
HDF5 group to read from
Returns
-------
openmc.data.ProbabilityTables
Probability tables
"""
interpolation = group.attrs['interpolation']
inelastic_flag = group.attrs['inelastic']
absorption_flag = group.attrs['absorption']
multiply_smooth = bool(group.attrs['multiply_smooth'])
energy = group['energy'][()]
table = group['table'][()]
return cls(energy, table, interpolation, inelastic_flag,
absorption_flag, multiply_smooth)
[docs] @classmethod
def from_ace(cls, ace):
"""Generate probability tables from an ACE table
Parameters
----------
ace : openmc.data.ace.Table
ACE table to read from
Returns
-------
openmc.data.ProbabilityTables
Unresolved resonance region probability tables
"""
# Check if URR probability tables are present
idx = ace.jxs[23]
if idx == 0:
return None
N = int(ace.xss[idx]) # Number of incident energies
M = int(ace.xss[idx+1]) # Length of probability table
interpolation = int(ace.xss[idx+2])
inelastic_flag = int(ace.xss[idx+3])
absorption_flag = int(ace.xss[idx+4])
multiply_smooth = (int(ace.xss[idx+5]) == 1)
idx += 6
# Get energies at which tables exist
energy = ace.xss[idx : idx+N]*EV_PER_MEV
idx += N
# Get probability tables
table = ace.xss[idx : idx+N*6*M].copy()
table.shape = (N, 6, M)
# Convert units on heating numbers
table[:,5,:] *= EV_PER_MEV
return cls(energy, table, interpolation, inelastic_flag,
absorption_flag, multiply_smooth)