import sys
import openmc
from openmc.checkvalue import check_type, check_length
from openmc.data import natural_abundance
if sys.version_info[0] >= 3:
basestring = str
[docs]class Element(object):
"""A natural element used in a material via <element>. Internally, OpenMC will
expand the natural element into isotopes based on the known natural
abundances.
Parameters
----------
name : str
Chemical symbol of the element, e.g. Pu
xs : str
Cross section identifier, e.g. 71c
Attributes
----------
name : str
Chemical symbol of the element, e.g. Pu
xs : str
Cross section identifier, e.g. 71c
scattering : {'data', 'iso-in-lab', None}
The type of angular scattering distribution to use
"""
def __init__(self, name='', xs=None):
# Initialize class attributes
self._name = ''
self._xs = None
self._scattering = None
# Set class attributes
self.name = name
if xs is not None:
self.xs = xs
def __eq__(self, other):
if isinstance(other, Element):
if self.name != other.name:
return False
elif self.xs != other.xs:
return False
else:
return True
elif isinstance(other, basestring) and other == self.name:
return True
else:
return False
def __ne__(self, other):
return not self == other
def __gt__(self, other):
return repr(self) > repr(other)
def __lt__(self, other):
return not self > other
def __hash__(self):
return hash(repr(self))
def __repr__(self):
string = 'Element - {0}\n'.format(self._name)
string += '{0: <16}{1}{2}\n'.format('\tXS', '=\t', self._xs)
if self.scattering is not None:
string += '{0: <16}{1}{2}\n'.format('\tscattering', '=\t',
self.scattering)
return string
@property
def xs(self):
return self._xs
@property
def name(self):
return self._name
@property
def scattering(self):
return self._scattering
@xs.setter
def xs(self, xs):
check_type('cross section identifier', xs, basestring)
self._xs = xs
@name.setter
def name(self, name):
check_type('element name', name, basestring)
check_length('element name', name, 1, 2)
self._name = name
@scattering.setter
def scattering(self, scattering):
if not scattering in ['data', 'iso-in-lab']:
msg = 'Unable to set scattering for Element to {0} ' \
'which is not "data" or "iso-in-lab"'.format(scattering)
raise ValueError(msg)
self._scattering = scattering
[docs] def expand(self):
"""Expand natural element into its naturally-occurring isotopes.
Returns
-------
isotopes : list
Naturally-occurring isotopes of the element. Each item of the list
is a tuple consisting of an openmc.Nuclide instance and the natural
abundance of the isotope.
"""
isotopes = []
for isotope, abundance in sorted(natural_abundance.items()):
if isotope.startswith(self.name + '-'):
nuc = openmc.Nuclide(isotope, self.xs)
isotopes.append((nuc, abundance))
return isotopes