OpenMC/include/openmc/particle.h
2019-10-28 11:55:45 -05:00

292 lines
11 KiB
C++

#ifndef OPENMC_PARTICLE_H
#define OPENMC_PARTICLE_H
//! \file particle.h
//! \brief Particle type
#include <array>
#include <cstdint>
#include <memory> // for unique_ptr
#include <sstream>
#include <string>
#include <vector>
#include "openmc/constants.h"
#include "openmc/position.h"
namespace openmc {
//==============================================================================
// Constants
//==============================================================================
// Since cross section libraries come with different numbers of delayed groups
// (e.g. ENDF/B-VII.1 has 6 and JEFF 3.1.1 has 8 delayed groups) and we don't
// yet know what cross section library is being used when the tallies.xml file
// is read in, we want to have an upper bound on the size of the array we
// use to store the bins for delayed group tallies.
constexpr int MAX_DELAYED_GROUPS {8};
// Maximum number of lost particles
constexpr int MAX_LOST_PARTICLES {10};
// Maximum number of lost particles, relative to the total number of particles
constexpr double REL_MAX_LOST_PARTICLES {1.0e-6};
constexpr double CACHE_INVALID {-1.0};
//==============================================================================
// Class declarations
//==============================================================================
class LocalCoord {
public:
void rotate(const std::vector<double>& rotation);
//! clear data from a single coordinate level
void reset();
Position r; //!< particle position
Direction u; //!< particle direction
int cell {-1};
int universe {-1};
int lattice {-1};
int lattice_x {-1};
int lattice_y {-1};
int lattice_z {-1};
bool rotated {false}; //!< Is the level rotated?
};
//==============================================================================
//! Cached microscopic cross sections for a particular nuclide at the current
//! energy
//==============================================================================
struct NuclideMicroXS {
// Microscopic cross sections in barns
double total; //!< total cross section
double absorption; //!< absorption (disappearance)
double fission; //!< fission
double nu_fission; //!< neutron production from fission
double elastic; //!< If sab_frac is not 1 or 0, then this value is
//!< averaged over bound and non-bound nuclei
double thermal; //!< Bound thermal elastic & inelastic scattering
double thermal_elastic; //!< Bound thermal elastic scattering
double photon_prod; //!< microscopic photon production xs
// Cross sections for depletion reactions (note that these are not stored in
// macroscopic cache)
double reaction[DEPLETION_RX.size()];
// Indicies and factors needed to compute cross sections from the data tables
int index_grid; //!< Index on nuclide energy grid
int index_temp; //!< Temperature index for nuclide
double interp_factor; //!< Interpolation factor on nuc. energy grid
int index_sab {-1}; //!< Index in sab_tables
int index_temp_sab; //!< Temperature index for sab_tables
double sab_frac; //!< Fraction of atoms affected by S(a,b)
bool use_ptable; //!< In URR range with probability tables?
// Energy and temperature last used to evaluate these cross sections. If
// these values have changed, then the cross sections must be re-evaluated.
double last_E {0.0}; //!< Last evaluated energy
double last_sqrtkT {0.0}; //!< Last temperature in sqrt(Boltzmann constant
//!< * temperature (eV))
};
//==============================================================================
//! Cached microscopic photon cross sections for a particular element at the
//! current energy
//==============================================================================
struct ElementMicroXS {
int index_grid; //!< index on element energy grid
double last_E {0.0}; //!< last evaluated energy in [eV]
double interp_factor; //!< interpolation factor on energy grid
double total; //!< microscopic total photon xs
double coherent; //!< microscopic coherent xs
double incoherent; //!< microscopic incoherent xs
double photoelectric; //!< microscopic photoelectric xs
double pair_production; //!< microscopic pair production xs
};
//==============================================================================
// MACROXS contains cached macroscopic cross sections for the material a
// particle is traveling through
//==============================================================================
struct MacroXS {
double total; //!< macroscopic total xs
double absorption; //!< macroscopic absorption xs
double fission; //!< macroscopic fission xs
double nu_fission; //!< macroscopic production xs
double photon_prod; //!< macroscopic photon production xs
// Photon cross sections
double coherent; //!< macroscopic coherent xs
double incoherent; //!< macroscopic incoherent xs
double photoelectric; //!< macroscopic photoelectric xs
double pair_production; //!< macroscopic pair production xs
};
//============================================================================
//! State of a particle being transported through geometry
//============================================================================
class Particle {
public:
//==========================================================================
// Aliases and type definitions
//! Particle types
enum class Type {
neutron, photon, electron, positron
};
//! Saved ("banked") state of a particle
struct Bank {
Position r;
Direction u;
double E;
double wgt;
int delayed_group;
Type particle;
};
//==========================================================================
// Constructors
Particle();
//==========================================================================
// Methods and accessors
// Accessors for position in global coordinates
Position& r() { return coord_[0].r; }
const Position& r() const { return coord_[0].r; }
// Accessors for position in local coordinates
Position& r_local() { return coord_[n_coord_ - 1].r; }
const Position& r_local() const { return coord_[n_coord_ - 1].r; }
// Accessors for direction in global coordinates
Direction& u() { return coord_[0].u; }
const Direction& u() const { return coord_[0].u; }
// Accessors for direction in local coordinates
Direction& u_local() { return coord_[n_coord_ - 1].u; }
const Direction& u_local() const { return coord_[n_coord_ - 1].u; }
//! resets all coordinate levels for the particle
void clear();
//! create a secondary particle
//
//! stores the current phase space attributes of the particle in the
//! secondary bank and increments the number of sites in the secondary bank.
//! \param u Direction of the secondary particle
//! \param E Energy of the secondary particle in [eV]
//! \param type Particle type
void create_secondary(Direction u, double E, Type type);
//! initialize from a source site
//
//! initializes a particle from data stored in a source site. The source
//! site may have been produced from an external source, from fission, or
//! simply as a secondary particle.
//! \param src Source site data
void from_source(const Bank* src);
//! Transport a particle from birth to death
void transport();
//! Cross a surface and handle boundary conditions
void cross_surface();
//! mark a particle as lost and create a particle restart file
//! \param message A warning message to display
void mark_as_lost(const char* message);
void mark_as_lost(const std::string& message)
{mark_as_lost(message.c_str());}
void mark_as_lost(const std::stringstream& message)
{mark_as_lost(message.str());}
//! create a particle restart HDF5 file
void write_restart() const;
//==========================================================================
// Data members
// Cross section caches
std::vector<NuclideMicroXS> neutron_xs_; //!< Microscopic neutron cross sections
std::vector<ElementMicroXS> photon_xs_; //!< Microscopic photon cross sections
MacroXS macro_xs_; //!< Macroscopic cross sections
int64_t id_; //!< Unique ID
Type type_ {Type::neutron}; //!< Particle type (n, p, e, etc.)
int n_coord_ {1}; //!< number of current coordinate levels
int cell_instance_; //!< offset for distributed properties
std::vector<LocalCoord> coord_; //!< coordinates for all levels
// Particle coordinates before crossing a surface
int n_coord_last_ {1}; //!< number of current coordinates
std::vector<int> cell_last_; //!< coordinates for all levels
// Energy data
double E_; //!< post-collision energy in eV
double E_last_; //!< pre-collision energy in eV
int g_ {0}; //!< post-collision energy group (MG only)
int g_last_; //!< pre-collision energy group (MG only)
// Other physical data
double wgt_ {1.0}; //!< particle weight
double mu_; //!< angle of scatter
bool alive_ {true}; //!< is particle alive?
// Other physical data
Position r_last_current_; //!< coordinates of the last collision or
//!< reflective/periodic surface crossing for
//!< current tallies
Position r_last_; //!< previous coordinates
Direction u_last_; //!< previous direction coordinates
double wgt_last_ {1.0}; //!< pre-collision particle weight
double wgt_absorb_ {0.0}; //!< weight absorbed for survival biasing
// What event took place
bool fission_ {false}; //!< did particle cause implicit fission
int event_; //!< scatter, absorption
int event_nuclide_; //!< index in nuclides array
int event_mt_; //!< reaction MT
int delayed_group_ {0}; //!< delayed group
// Post-collision physical data
int n_bank_ {0}; //!< number of fission sites banked
int n_bank_second_ {0}; //!< number of secondary particles banked
double wgt_bank_ {0.0}; //!< weight of fission sites banked
int n_delayed_bank_[MAX_DELAYED_GROUPS]; //!< number of delayed fission
//!< sites banked
// Indices for various arrays
int surface_ {0}; //!< index for surface particle is on
int cell_born_ {-1}; //!< index for cell particle was born in
int material_ {-1}; //!< index for current material
int material_last_ {-1}; //!< index for last material
// Temperature of current cell
double sqrtkT_ {-1.0}; //!< sqrt(k_Boltzmann * temperature) in eV
double sqrtkT_last_ {0.0}; //!< last temperature
// Statistical data
int n_collision_ {0}; //!< number of collisions
// Track output
bool write_track_ {false};
};
} // namespace openmc
#endif // OPENMC_PARTICLE_H