CADIS WW geneartion from adjoint solution on exodus files

include/openmc/mesh.h

@@ -994,6 +994,15 @@ class LibMesh : public UnstructuredMesh {
   LibMesh(const std::string& filename, double length_multiplier = 1.0);
   LibMesh(libMesh::MeshBase& input_mesh, double length_multiplier = 1.0);
 
+  //! Create a mesh from an externally constructed libMesh mesh, transferring
+  //! ownership of the mesh to OpenMC
+  //
+  //! \param[in] input_mesh Externally built mesh (must be replicated)
+  //! \param[in] length_multiplier Multiplier applied to mesh coordinates
+  //! \param[in] filename Name of the file the mesh was read from, if any
+  LibMesh(unique_ptr<libMesh::MeshBase> input_mesh,
+    double length_multiplier = 1.0, const std::string& filename = "");
+
   static const std::string mesh_lib_type;
 
   // Overridden Methods

include/openmc/weight_windows.h

@@ -244,6 +244,11 @@ void apply_weight_window(Particle& p, WeightWindow weight_window);
 //! Free memory associated with weight windows
 void free_memory_weight_windows();
 
+//! Build a WeightWindows object from multigroup adjoint flux stored as
+//! elemental data in an Exodus II file (requires libMesh support)
+//! \param[in] node XML node for <weight_windows_exodus> in settings.xml
+void read_weight_windows_exodus(pugi::xml_node node);
+
 //! Search weight window that apply to a particle
 //! \param[in]  p  Particle to search weight window for
 std::pair<bool, WeightWindow> search_weight_window(const Particle& p);

openmc/settings.py

@@ -17,7 +17,8 @@
 from .source import SourceBase, MeshSource, IndependentSource
 from .utility_funcs import input_path
 from .volume import VolumeCalculation
-from .weight_windows import WeightWindows, WeightWindowGenerator, WeightWindowsList
+from .weight_windows import (WeightWindows, WeightWindowGenerator,
+                             WeightWindowsList, WeightWindowsExodus)
 
 
 class RunMode(Enum):
@@ -395,6 +396,12 @@ class Settings:
         Path to a weight window file to load during simulation initialization
 
         .. versionadded::0.14.0
+    weight_windows_exodus : openmc.WeightWindowsExodus
+        Specification for building weight windows from multigroup adjoint flux
+        stored as elemental data in an Exodus file. Requires OpenMC to be
+        built with libMesh support.
+
+        .. versionadded:: 0.15.4
     write_initial_source : bool
         Indicate whether to write the initial source distribution to file
     """
@@ -493,6 +500,7 @@ def __init__(self, **kwargs):
         self._weight_windows_on = None
         self._shared_secondary_bank = None
         self._weight_windows_file = None
+        self._weight_windows_exodus = None
         self._weight_window_checkpoints = {}
         self._max_history_splits = None
         self._max_tracks = None
@@ -1383,6 +1391,16 @@ def weight_windows_file(self, value: PathLike | None):
             cv.check_type('weight windows file', value, PathLike)
             self._weight_windows_file = input_path(value)
 
+    @property
+    def weight_windows_exodus(self) -> WeightWindowsExodus | None:
+        return self._weight_windows_exodus
+
+    @weight_windows_exodus.setter
+    def weight_windows_exodus(self, value: WeightWindowsExodus | None):
+        if value is not None:
+            cv.check_type('weight windows exodus', value, WeightWindowsExodus)
+        self._weight_windows_exodus = value
+
     @property
     def weight_window_generators(self) -> list[WeightWindowGenerator]:
         return self._weight_window_generators
@@ -1973,6 +1991,10 @@ def _create_weight_windows_file_element(self, root):
             element.text = str(self.weight_windows_file)
             root.append(element)
 
+    def _create_weight_windows_exodus_subelement(self, root):
+        if self._weight_windows_exodus is not None:
+            root.append(self._weight_windows_exodus.to_xml_element())
+
     def _create_weight_window_checkpoints_subelement(self, root):
         if not self._weight_window_checkpoints:
             return
@@ -2464,6 +2486,11 @@ def _weight_windows_file_from_xml_element(self, root):
         if text is not None:
             self.weight_windows_file = text
 
+    def _weight_windows_exodus_from_xml_element(self, root):
+        elem = root.find('weight_windows_exodus')
+        if elem is not None:
+            self.weight_windows_exodus = WeightWindowsExodus.from_xml_element(elem)
+
     def _weight_window_checkpoints_from_xml_element(self, root):
         elem = root.find('weight_window_checkpoints')
         if elem is None:
@@ -2629,6 +2656,7 @@ def to_xml_element(self, mesh_memo=None):
         self._create_shared_secondary_bank_subelement(element)
         self._create_weight_window_generators_subelement(element, mesh_memo)
         self._create_weight_windows_file_element(element)
+        self._create_weight_windows_exodus_subelement(element)
         self._create_weight_window_checkpoints_subelement(element)
         self._create_max_history_splits_subelement(element)
         self._create_max_tracks_subelement(element)
@@ -2746,6 +2774,7 @@ def from_xml_element(cls, elem, meshes=None):
         settings._weight_windows_on_from_xml_element(elem)
         settings._shared_secondary_bank_from_xml_element(elem)
         settings._weight_windows_file_from_xml_element(elem)
+        settings._weight_windows_exodus_from_xml_element(elem)
         settings._weight_window_generators_from_xml_element(elem, meshes)
         settings._weight_window_checkpoints_from_xml_element(elem)
         settings._max_history_splits_from_xml_element(elem)