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Merge pull request openmc-dev#2222 from highness-eu/mixed_ncrystal
Adding support for NCrystal materials in OpenMC
2 parents 0db1d74 + bdafa70 commit 4a8d700

30 files changed

Lines changed: 861 additions & 45 deletions

‎.github/workflows/ci.yml‎

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@@ -29,6 +29,7 @@ jobs:
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mpi: [n, y]
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omp: [n, y]
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dagmc: [n]
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ncrystal: [n]
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libmesh: [n]
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event: [n]
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vectfit: [n]
@@ -47,6 +48,10 @@ jobs:
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python-version: '3.10'
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mpi: y
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omp: y
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- ncrystal: y
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python-version: '3.10'
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mpi: n
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omp: n
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- libmesh: y
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python-version: '3.10'
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mpi: y
@@ -64,7 +69,7 @@ jobs:
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omp: n
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mpi: y
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name: "Python ${{ matrix.python-version }} (omp=${{ matrix.omp }},
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mpi=${{ matrix.mpi }}, dagmc=${{ matrix.dagmc }},
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mpi=${{ matrix.mpi }}, dagmc=${{ matrix.dagmc }}, ncrystal=${{ matrix.ncrystal }},
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libmesh=${{ matrix.libmesh }}, event=${{ matrix.event }}
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vectfit=${{ matrix.vectfit }})"
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@@ -73,6 +78,7 @@ jobs:
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PHDF5: ${{ matrix.mpi }}
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OMP: ${{ matrix.omp }}
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DAGMC: ${{ matrix.dagmc }}
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NCRYSTAL: ${{ matrix.ncrystal }}
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EVENT: ${{ matrix.event }}
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VECTFIT: ${{ matrix.vectfit }}
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LIBMESH: ${{ matrix.libmesh }}

‎CMakeLists.txt‎

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@@ -37,6 +37,7 @@ option(OPENMC_USE_DAGMC "Enable support for DAGMC (CAD) geometry"
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option(OPENMC_USE_LIBMESH "Enable support for libMesh unstructured mesh tallies" OFF)
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option(OPENMC_USE_MPI "Enable MPI" OFF)
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option(OPENMC_USE_MCPL "Enable MCPL" OFF)
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option(OPENMC_USE_NCRYSTAL "Enable support for NCrystal scattering" OFF)
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# Warnings for deprecated options
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foreach(OLD_OPT IN ITEMS "openmp" "profile" "coverage" "dagmc" "libmesh")
@@ -99,6 +100,15 @@ macro(find_package_write_status pkg)
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endif()
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endmacro()
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#===============================================================================
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# NCrystal Scattering Support
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#===============================================================================
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if(OPENMC_USE_NCRYSTAL)
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find_package(NCrystal REQUIRED)
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message(STATUS "Found NCrystal: ${NCrystal_DIR} (version ${NCrystal_VERSION})")
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endif()
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#===============================================================================
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# DAGMC Geometry Support - need DAGMC/MOAB
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#===============================================================================
@@ -338,6 +348,7 @@ list(APPEND libopenmc_SOURCES
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src/message_passing.cpp
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src/mgxs.cpp
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src/mgxs_interface.cpp
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src/ncrystal_interface.cpp
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src/nuclide.cpp
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src/output.cpp
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src/particle.cpp
@@ -498,6 +509,11 @@ if (OPENMC_USE_MCPL)
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target_link_libraries(libopenmc MCPL::mcpl)
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endif()
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if(OPENMC_USE_NCRYSTAL)
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target_compile_definitions(libopenmc PRIVATE NCRYSTAL)
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target_link_libraries(libopenmc NCrystal::NCrystal)
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endif()
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#===============================================================================
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# Log build info that this executable can report later
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#===============================================================================

‎cmake/OpenMCConfig.cmake.in‎

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@@ -9,6 +9,11 @@ if(@OPENMC_USE_DAGMC@)
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find_package(DAGMC REQUIRED HINTS @DAGMC_DIR@)
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endif()
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if(@OPENMC_USE_NCRYSTAL@)
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find_package(NCrystal REQUIRED)
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message(STATUS "Found NCrystal: ${NCrystal_DIR} (version ${NCrystal_VERSION})")
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endif()
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if(@OPENMC_USE_LIBMESH@)
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include(FindPkgConfig)
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list(APPEND CMAKE_PREFIX_PATH @LIBMESH_PREFIX@)

‎docs/source/methods/cross_sections.rst‎

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@@ -178,6 +178,27 @@ been selected. There are three methods available:
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section data is loaded for a single temperature and is used in the
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unresolved resonance and fast energy ranges.
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------------------
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NCrystal materials
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------------------
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As an alternative of the standard thermal scattering treatment using
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:math:`S(\alpha,\beta)` tables, OpenMC allows to create materials using
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NCrystal_. In addition to the regular thermal elastic, and thermal inelastic
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processes, NCrystal allows the generation of models for materials that cannot
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currently included in ACE files such as oriented single crystals (see the
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`NCrystal paper`_), and further extend the physics `using plugins`_. Thermal
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scattering kernels are generated on the fly from dynamic and structural data, or
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loaded from :math:`S(\alpha,\beta)` tables converted from ENDF6 evaluations.
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These kernels are sampled in a direct way using a fast `rejection algorithm`_
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that does not require previous processing. A `large library`_ of materials is
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already included in the NCrystal distribution, and new materials can be easily
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defined from scratch in the `NCMAT format`_ or `combining existing files`_.
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The compositions of the materials defined in NCrystal are passed on to OpenMC
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all other reactions except for thermal neutron scattering are handled by
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continuous energy ACE libraries.
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----------------
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Multi-Group Data
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----------------
@@ -279,3 +300,10 @@ or even isotropic scattering.
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.. _ENDF/B data: https://www.nndc.bnl.gov/endf-b8.0/
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.. _Leppanen: https://doi.org/10.1016/j.anucene.2009.03.019
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.. _algorithms: http://ab-initio.mit.edu/wiki/index.php/Faddeeva_Package
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.. _NCrystal: https://github.com/mctools/ncrystal
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.. _NCrystal paper: https://doi.org/10.1016/j.cpc.2019.07.015
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.. _using plugins: https://doi.org/10.1016/j.cpc.2021.108082
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.. _rejection algorithm: https://doi.org/10.1016/j.jcp.2018.11.043
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.. _large library: https://github.com/mctools/ncrystal/wiki/Data-library
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.. _NCMAT format: https://github.com/mctools/ncrystal/wiki/NCMAT-format
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.. _combining existing files: https://github.com/mctools/ncrystal/wiki/Announcement-Release3.0.0#2-multiphase-materials

‎docs/source/usersguide/install.rst‎

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@@ -271,6 +271,17 @@ Prerequisites
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cmake -DOPENMC_USE_DAGMC=on -DCMAKE_PREFIX_PATH=/path/to/dagmc/installation ..
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* NCrystal_ library for defining materials with enhanced thermal neutron transport
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Adding this option allows the creation of materials from NCrystal, which
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replaces the scattering kernel treatment of ACE files with a modular,
278+
on-the-fly approach. To use it `install
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<https://github.com/mctools/ncrystal/wiki/Get-NCrystal>`_ and `initialize
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<https://github.com/mctools/ncrystal/wiki/Using-NCrystal#setting-up>`_
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NCrystal and turn on the option in the CMake configuration step:
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cmake -DOPENMC_USE_NCRYSTAL=on ..
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* libMesh_ mesh library framework for numerical simulations of partial differential equations
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This optional dependency enables support for unstructured mesh tally
@@ -294,6 +305,7 @@ Prerequisites
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.. _MOAB: https://bitbucket.org/fathomteam/moab
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.. _libMesh: https://libmesh.github.io/
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.. _libpng: http://www.libpng.org/pub/png/libpng.html
308+
.. _NCrystal: https://github.com/mctools/ncrystal
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Obtaining the Source
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--------------------
@@ -362,6 +374,12 @@ OPENMC_USE_DAGMC
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should also be defined as `DAGMC_ROOT` in the CMake configuration command.
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(Default: off)
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377+
OPENMC_USE_NCRYSTAL
378+
Turns on support for NCrystal materials. NCrystal must be
379+
`installed <https://github.com/mctools/ncrystal/wiki/Get-NCrystal>`_ and
380+
`initialized <https://github.com/mctools/ncrystal/wiki/Using-NCrystal#setting-up>`_.
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(Default: off)
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OPENMC_USE_LIBMESH
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Enables the use of unstructured mesh tallies with libMesh_. (Default: off)
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‎docs/source/usersguide/materials.rst‎

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@@ -101,6 +101,42 @@ you would need to add hydrogen and oxygen to a material and then assign the
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.. _usersguide_naming:
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-------------------------
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Adding NCrystal materials
106+
-------------------------
107+
108+
Additional support for thermal scattering can be added by using NCrystal_. The
109+
:meth:`Material.from_ncrystal` class method generates a :class:`openmc.Material`
110+
object from an `NCrystal configuration string
111+
<https://github.com/mctools/ncrystal/wiki/Using-NCrystal#uniform-material-configuration-syntax>`_.
112+
Temperature, material composition, and density are passed from the configuration
113+
string and the `NCMAT file
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<https://github.com/mctools/ncrystal/wiki/NCMAT-format>`_ that define the
115+
material, e.g.::
116+
117+
mat = openmc.Material.from_ncrystal('Al_sg225.ncmat;temp=300K')
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defines a material containing polycrystalline alumnium,
120+
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::
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123+
mat = openmc.Material.from_ncrystal("""Ge_sg227.ncmat;dcutoff=0.5;mos=40arcsec;
124+
dir1=@crys_hkl:5,1,1@lab:0,0,1;
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dir2=@crys_hkl:0,-1,1@lab:0,1,0""")
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defines an oriented germanium single crystal with 40 arcsec mosaicity.
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NCrystal only handles low energy neutron interactions. Other interactions are
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provided by standard ACE files. NCrystal_ comes with a `predefined library
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<https://github.com/mctools/ncrystal/wiki/Data-library>`_ but more materials can
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be added by creating NCMAT files or on-the-fly in the configuration string.
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.. warning:: Currently, NCrystal_ materials cannot be modified after they are created.
135+
Density, temperature and composition should be defined in the
136+
configuration string or the NCMAT file.
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.. _NCrystal: https://github.com/mctools/ncrystal
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------------------
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Naming Conventions
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------------------
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materials.cross_sections = '/path/to/cross_sections.xml'
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.. _MCNP: https://mcnp.lanl.gov/
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‎include/openmc/file_utils.h‎

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@@ -14,7 +14,8 @@ namespace openmc {
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inline bool dir_exists(const std::string& path)
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{
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struct stat s;
17-
if (stat(path.c_str(), &s) != 0) return false;
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if (stat(path.c_str(), &s) != 0)
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return false;
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1920
return s.st_mode & S_IFDIR;
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}

‎include/openmc/material.h‎

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#include "openmc/bremsstrahlung.h"
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#include "openmc/constants.h"
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#include "openmc/memory.h" // for unique_ptr
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#include "openmc/ncrystal_interface.h"
1516
#include "openmc/particle.h"
1617
#include "openmc/vector.h"
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@@ -151,12 +152,17 @@ class Material {
151152
//! \return Temperature in [K]
152153
double temperature() const;
153154

155+
//! Get pointer to NCrystal material object
156+
//! \return Pointer to NCrystal material object
157+
const NCrystalMat& ncrystal_mat() const { return ncrystal_mat_; };
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154159
//----------------------------------------------------------------------------
155160
// Data
156161
int32_t id_ {C_NONE}; //!< Unique ID
157162
std::string name_; //!< Name of material
158163
vector<int> nuclide_; //!< Indices in nuclides vector
159164
vector<int> element_; //!< Indices in elements vector
165+
NCrystalMat ncrystal_mat_; //!< NCrystal material object
160166
xt::xtensor<double, 1> atom_density_; //!< Nuclide atom density in [atom/b-cm]
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double density_; //!< Total atom density in [atom/b-cm]
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double density_gpcc_; //!< Total atom density in [g/cm^3]

‎include/openmc/ncrystal_interface.h‎

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#ifndef OPENMC_NCRYSTAL_INTERFACE_H
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#define OPENMC_NCRYSTAL_INTERFACE_H
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#ifdef NCRYSTAL
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#include "NCrystal/NCRNG.hh"
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#include "NCrystal/NCrystal.hh"
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#endif
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#include "openmc/particle.h"
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#include <cstdint> // for uint64_t
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#include <limits> // for numeric_limits
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#include <string>
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namespace openmc {
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//==============================================================================
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// Constants
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//==============================================================================
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extern "C" const bool NCRYSTAL_ENABLED;
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//! Energy in [eV] to switch between NCrystal and ENDF
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constexpr double NCRYSTAL_MAX_ENERGY {5.0};
25+
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//==============================================================================
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// Wrapper class an NCrystal material
28+
//==============================================================================
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class NCrystalMat {
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public:
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//----------------------------------------------------------------------------
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// Constructors
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NCrystalMat() = default;
35+
explicit NCrystalMat(const std::string& cfg);
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//----------------------------------------------------------------------------
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// Methods
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#ifdef NCRYSTAL
41+
//! Return configuration string
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std::string cfg() const;
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//! Get cross section from NCrystal material
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//
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//! \param[in] p Particle object
47+
//! \return Cross section in [b]
48+
double xs(const Particle& p) const;
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// Process scattering event
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//
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//! \param[in] p Particle object
53+
void scatter(Particle& p) const;
54+
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//! Whether the object holds a valid NCrystal material
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operator bool() const;
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#else
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//----------------------------------------------------------------------------
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// Trivial methods when compiling without NCRYSTAL
61+
std::string cfg() const
62+
{
63+
return "";
64+
}
65+
double xs(const Particle& p) const
66+
{
67+
return -1.0;
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}
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void scatter(Particle& p) const {}
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operator bool() const
71+
{
72+
return false;
73+
}
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#endif
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private:
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//----------------------------------------------------------------------------
78+
// Data members (only present when compiling with NCrystal support)
79+
#ifdef NCRYSTAL
80+
std::string cfg_; //!< NCrystal configuration string
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std::shared_ptr<const NCrystal::ProcImpl::Process>
82+
ptr_; //!< Pointer to NCrystal material object
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#endif
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};
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//==============================================================================
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// Functions
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//==============================================================================
89+
90+
void ncrystal_update_micro(double xs, NuclideMicroXS& micro);
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} // namespace openmc
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#endif // OPENMC_NCRYSTAL_INTERFACE_H

‎include/openmc/physics.h‎

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@@ -96,8 +96,9 @@ void inelastic_scatter(const Nuclide& nuc, const Reaction& rx, Particle& p);
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void sample_secondary_photons(Particle& p, int i_nuclide);
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99-
//！Split or Roulette particles based their weight and the lower weight window
100-
// bound.
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//! Split or Roulette particles based their weight and the lower weight window
100+
//! bound.
101+
//
101102
//! \param[in] p, particle to be split or rouletted with the weight window.
102103
void split_particle(Particle& p);
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