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Nick Horelik 2014-09-12 10:12:01 -04:00
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65
docs/source/usersguide/input.rst
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@ -260,6 +260,65 @@ or sub-elements and can be set to either "false" or "true".
*Default*: true
``<resonance_scattering>`` Element
----------------------
The ``resonance_scattering`` element can contain one or more of the following
attributes or sub-elements:
:scatterer:
An element with attributes/sub-elements called ``nuclide``, ``method``,
``xs_label``, ``xs_label_0K``, ``E_min``, and ``E_max``. The ``nuclide``
attribute is the name, as given by the ``name`` attribute within the
``nuclide`` sub-element of the ``material`` element in ``materials.xml``,
of the nuclide to which a resonance scattering treatment is to be applied.
The ``method`` attribute gives the type of resonance scattering treatment
that is to be applied to the ``nuclide``. Acceptable inputs - none of
which are case-sensitive - for the ``method`` attribute are ``ARES``,
``CXS``, ``WCM``, and ``DBRC``. Descriptions of each of these methods
are documented here_. The ``xs_label`` attribute gives the label for the
cross section data of the ``nuclide`` at a given temperature. The
``xs_label_0K`` gives the label for the 0 K cross section data for the
``nuclide``. The ``E_min`` attribute gives the minimum energy above
which the ``method`` is applied. The ``E_max`` attribute gives the
maximum energy below which the ``method`` is applied. One example would
be as follows:
.. _here: http://dx.doi.org/10.1016/j.anucene.2014.01.017
.. code-block:: xml
<resonance_scattering>
<scatterer>
<nuclide>U-238</nuclide>
<method>ARES</method>
<xs_label>92238.72c</xs_label>
<xs_label_0K>92238.00c</xs_label_0K>
<E_min>5.0e-6</E_min>
<E_max>40.0e-6</E_max>
</scatterer>
<scatterer>
<nuclide>Pu-239</nuclide>
<method>dbrc</method>
<xs_label>94239.72c</xs_label>
<xs_label_0K>94239.00c</xs_label_0K>
<E_min>0.01e-6</E_min>
<E_max>210.0e-6</E_max>
</scatterer>
</resonance_scattering>
.. note:: If the ``resonance_scattering`` element is not given, the free gas,
constant cross section (``cxs``) scattering model, which has
historically been used by Monte Carlo codes to sample target
velocities, is used to treat the target motion of all nuclides. If
``resonance_scattering`` is present, the ``cxs`` method is applied
below ``E_min`` and the target-at-rest (asymptotic) kernel is used
above ``E_max``. An arbitrary number of ``scatterer`` elements may
be specified, each corresponding to a single nuclide at a single
temperature.
*Defaults*: None (scatterer), ARES (method), 0.01 eV (E_min), 1.0 keV (E_max)
``<run_cmfd>`` Element
----------------------
@ -311,6 +370,12 @@ attributes/sub-elements:
parallelepiped and the last three of which specify the upper-right
corner. Source sites are sampled uniformly through that parallelepiped.
To filter a "box" spatial distribution by fissionable material, specify
"fission" tag instead of "box". The ``parameters`` should be given as six
real numbers, the first three of which specify the lower-left corner of a
parallelepiped and the last three of which specify the upper-right
corner. Source sites are sampled uniformly through that parallelepiped.
For a "point" spatial distribution, ``parameters`` should be given as
three real numbers which specify the (x,y,z) location of an isotropic
point source