OpenMC/include/openmc/thermal.h
John Tramm 977ade79a1
Replace xtensor with internal Tensor/View classes (#3805)
Co-authored-by: John Tramm <jtramm@gmail.com>
2026-02-17 09:50:38 -06:00

119 lines
3.9 KiB
C++

#ifndef OPENMC_THERMAL_H
#define OPENMC_THERMAL_H
#include <cstddef>
#include <string>
#include <unordered_map>
#include "openmc/tensor.h"
#include "openmc/angle_energy.h"
#include "openmc/endf.h"
#include "openmc/hdf5_interface.h"
#include "openmc/memory.h"
#include "openmc/particle.h"
#include "openmc/vector.h"
namespace openmc {
//==============================================================================
// Global variables
//==============================================================================
class ThermalScattering;
namespace data {
extern std::unordered_map<std::string, int> thermal_scatt_map;
extern vector<unique_ptr<ThermalScattering>> thermal_scatt;
} // namespace data
//==============================================================================
//! Secondary angle-energy data for thermal neutron scattering at a single
//! temperature
//==============================================================================
class ThermalData {
public:
ThermalData(hid_t group);
//! Calculate the cross section
//
//! \param[in] E Incident neutron energy in [eV]
//! \param[out] elastic Elastic scattering cross section in [b]
//! \param[out] inelastic Inelastic scattering cross section in [b]
void calculate_xs(double E, double* elastic, double* inelastic) const;
//! Sample an outgoing energy and angle
//
//! \param[in] micro_xs Microscopic cross sections
//! \param[in] E_in Incident neutron energy in [eV]
//! \param[out] E_out Outgoing neutron energy in [eV]
//! \param[out] mu Outgoing scattering angle cosine
//! \param[inout] seed Pseudorandom seed pointer
void sample(const NuclideMicroXS& micro_xs, double E_in, double* E_out,
double* mu, uint64_t* seed);
private:
struct Reaction {
// Default constructor
Reaction() {}
// Data members
unique_ptr<Function1D> xs; //!< Cross section
unique_ptr<AngleEnergy>
distribution; //!< Secondary angle-energy distribution
};
// Inelastic scattering data
Reaction elastic_;
Reaction inelastic_;
// ThermalScattering needs access to private data members
friend class ThermalScattering;
};
//==============================================================================
//! Data for thermal neutron scattering, typically off light isotopes in
//! moderating materials such as water, graphite, BeO, etc.
//==============================================================================
class ThermalScattering {
public:
ThermalScattering(hid_t group, const vector<double>& temperature);
//! Determine inelastic/elastic cross section at given energy
//!
//! \param[in] E incoming energy in [eV]
//! \param[in] sqrtkT square-root of temperature multipled by Boltzmann's
//! constant \param[out] i_temp corresponding temperature index \param[out]
//! elastic Thermal elastic scattering cross section \param[out] inelastic
//! Thermal inelastic scattering cross section \param[inout] seed Pseudorandom
//! seed pointer
void calculate_xs(double E, double sqrtkT, int* i_temp, double* elastic,
double* inelastic, uint64_t* seed) const;
//! Determine whether table applies to a particular nuclide
//!
//! \param[in] name Name of the nuclide, e.g., "H1"
//! \return Whether table applies to the nuclide
bool has_nuclide(const char* name) const;
// Sample an outgoing energy and angle
void sample(
const NuclideMicroXS& micro_xs, double E_in, double* E_out, double* mu);
std::string name_; //!< name of table, e.g. "c_H_in_H2O"
double awr_; //!< weight of nucleus in neutron masses
double energy_max_; //!< maximum energy for thermal scattering in [eV]
vector<double> kTs_; //!< temperatures in [eV] (k*T)
vector<std::string> nuclides_; //!< Valid nuclides
//! cross sections and distributions at each temperature
vector<ThermalData> data_;
};
void free_memory_thermal();
} // namespace openmc
#endif // OPENMC_THERMAL_H