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SpECTRE
v2024.05.11
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Structure containing Monte-Carlo function templated on EnergyBins and/or NeutrinoSpecies. More...
#include <TemplatedLocalFunctions.hpp>
Public Member Functions | |
| void | emit_packets (gsl::not_null< std::vector< Packet > * > packets, gsl::not_null< std::mt19937 * > random_number_generator, gsl::not_null< Scalar< DataVector > * > coupling_tilde_tau, gsl::not_null< tnsr::i< DataVector, 3, Frame::Inertial > * > coupling_tilde_s, gsl::not_null< Scalar< DataVector > * > coupling_rho_ye, const double &time_start_step, const double &time_step, const Mesh< 3 > &mesh, const std::array< std::array< DataVector, EnergyBins >, NeutrinoSpecies > &emission_in_cell, const std::array< DataVector, NeutrinoSpecies > &single_packet_energy, const std::array< double, EnergyBins > &energy_at_bin_center, const Scalar< DataVector > &lorentz_factor, const tnsr::i< DataVector, 3, Frame::Inertial > &lower_spatial_four_velocity, const Jacobian< DataVector, 4, Frame::Inertial, Frame::Fluid > &inertial_to_fluid_jacobian, const InverseJacobian< DataVector, 4, Frame::Inertial, Frame::Fluid > &inertial_to_fluid_inverse_jacobian) |
| Function emitting Monte Carlo packets. More... | |
| void | evolve_packets (gsl::not_null< std::vector< Packet > * > packets, gsl::not_null< std::mt19937 * > random_number_generator, gsl::not_null< Scalar< DataVector > * > coupling_tilde_tau, gsl::not_null< tnsr::i< DataVector, 3, Frame::Inertial > * > coupling_tilde_s, gsl::not_null< Scalar< DataVector > * > coupling_rho_ye, double final_time, const Mesh< 3 > &mesh, const tnsr::I< DataVector, 3, Frame::ElementLogical > &mesh_coordinates, const std::array< std::array< DataVector, EnergyBins >, NeutrinoSpecies > &absorption_opacity_table, const std::array< std::array< DataVector, EnergyBins >, NeutrinoSpecies > &scattering_opacity_table, const std::array< double, EnergyBins > &energy_at_bin_center, const Scalar< DataVector > &lorentz_factor, const tnsr::i< DataVector, 3, Frame::Inertial > &lower_spatial_four_velocity, const Scalar< DataVector > &lapse, const tnsr::I< DataVector, 3, Frame::Inertial > &shift, const tnsr::i< DataVector, 3, Frame::Inertial > &d_lapse, const tnsr::iJ< DataVector, 3, Frame::Inertial > &d_shift, const tnsr::iJJ< DataVector, 3, Frame::Inertial > &d_inv_spatial_metric, const tnsr::ii< DataVector, 3, Frame::Inertial > &spatial_metric, const tnsr::II< DataVector, 3, Frame::Inertial > &inv_spatial_metric, const std::optional< tnsr::I< DataVector, 3, Frame::Inertial > > &mesh_velocity, const InverseJacobian< DataVector, 3, Frame::ElementLogical, Frame::Inertial > &inverse_jacobian_logical_to_inertial, const Jacobian< DataVector, 4, Frame::Inertial, Frame::Fluid > &inertial_to_fluid_jacobian, const InverseJacobian< DataVector, 4, Frame::Inertial, Frame::Fluid > &inertial_to_fluid_inverse_jacobian) |
| Evolve Monte-Carlo packets within an element. More... | |
| void | interpolate_opacities_at_fluid_energy (gsl::not_null< double * > absorption_opacity_packet, gsl::not_null< double * > scattering_opacity_packet, double fluid_frame_energy, size_t species, size_t index, const std::array< std::array< DataVector, EnergyBins >, NeutrinoSpecies > &absorption_opacity_table, const std::array< std::array< DataVector, EnergyBins >, NeutrinoSpecies > &scattering_opacity_table, const std::array< double, EnergyBins > &energy_at_bin_center) |
| Interpolate the opacities from values tabulated as a function of neutrino energy in the fluid frame, to the value at the given fluid frame energy. We interpolate the logarithm of the opacity, linearly in fluid frame energy. | |
Public Attributes | |
| const double | opacity_floor = 1.e-100 |
Structure containing Monte-Carlo function templated on EnergyBins and/or NeutrinoSpecies.
| void Particles::MonteCarlo::TemplatedLocalFunctions< EnergyBins, NeutrinoSpecies >::emit_packets | ( | gsl::not_null< std::vector< Packet > * > | packets, |
| gsl::not_null< std::mt19937 * > | random_number_generator, | ||
| gsl::not_null< Scalar< DataVector > * > | coupling_tilde_tau, | ||
| gsl::not_null< tnsr::i< DataVector, 3, Frame::Inertial > * > | coupling_tilde_s, | ||
| gsl::not_null< Scalar< DataVector > * > | coupling_rho_ye, | ||
| const double & | time_start_step, | ||
| const double & | time_step, | ||
| const Mesh< 3 > & | mesh, | ||
| const std::array< std::array< DataVector, EnergyBins >, NeutrinoSpecies > & | emission_in_cell, | ||
| const std::array< DataVector, NeutrinoSpecies > & | single_packet_energy, | ||
| const std::array< double, EnergyBins > & | energy_at_bin_center, | ||
| const Scalar< DataVector > & | lorentz_factor, | ||
| const tnsr::i< DataVector, 3, Frame::Inertial > & | lower_spatial_four_velocity, | ||
| const Jacobian< DataVector, 4, Frame::Inertial, Frame::Fluid > & | inertial_to_fluid_jacobian, | ||
| const InverseJacobian< DataVector, 4, Frame::Inertial, Frame::Fluid > & | inertial_to_fluid_inverse_jacobian | ||
| ) |
Function emitting Monte Carlo packets.
We emit a total energy emission_in_cell for each grid cell, neutrino species, and neutrino energy bin. We aim for packets of energy single_packet_energy in the fluid frame. The number of packets is, in each bin b and for each species s, N = emission_in_cell[s][b] / single_packet_energy[s] and randomly rounded up or down to get integer number of packets (i.e. if we want N=2.6 packets, there is a 60 percent chance of creating a 3rd packet). The position of the packets is drawn from a homogeneous distribution in the logical frame, and the direction of propagation of the neutrinos is drawn from an isotropic distribution in the fluid frame. Specifically, the 4-momentum of a packet of energy nu in the fluid frame is
\begin{align} p^t &= \nu \\ p^x &= \nu * sin(\theta) * cos(\phi) \\ p^y &= \nu * sin(\theta) * sin(\phi) \\ p^z &= \nu * cos(theta) \end{align}
with \(cos(\theta)\) drawn from a uniform distribution in [-1,1] and \(\phi\) from a uniform distribution in \([0,2*\pi]\). We transform to the inertial frame \(p_t\) and \(p^x,p^y,p^z\) using the jacobian/inverse jacobian passed as option. The number of neutrinos in each packet is defined as n = single_packet_energy[s] / energy_at_bin_center[b] Note that the packet energy is in code units and energy of a bin in MeV.
| void Particles::MonteCarlo::TemplatedLocalFunctions< EnergyBins, NeutrinoSpecies >::evolve_packets | ( | gsl::not_null< std::vector< Packet > * > | packets, |
| gsl::not_null< std::mt19937 * > | random_number_generator, | ||
| gsl::not_null< Scalar< DataVector > * > | coupling_tilde_tau, | ||
| gsl::not_null< tnsr::i< DataVector, 3, Frame::Inertial > * > | coupling_tilde_s, | ||
| gsl::not_null< Scalar< DataVector > * > | coupling_rho_ye, | ||
| double | final_time, | ||
| const Mesh< 3 > & | mesh, | ||
| const tnsr::I< DataVector, 3, Frame::ElementLogical > & | mesh_coordinates, | ||
| const std::array< std::array< DataVector, EnergyBins >, NeutrinoSpecies > & | absorption_opacity_table, | ||
| const std::array< std::array< DataVector, EnergyBins >, NeutrinoSpecies > & | scattering_opacity_table, | ||
| const std::array< double, EnergyBins > & | energy_at_bin_center, | ||
| const Scalar< DataVector > & | lorentz_factor, | ||
| const tnsr::i< DataVector, 3, Frame::Inertial > & | lower_spatial_four_velocity, | ||
| const Scalar< DataVector > & | lapse, | ||
| const tnsr::I< DataVector, 3, Frame::Inertial > & | shift, | ||
| const tnsr::i< DataVector, 3, Frame::Inertial > & | d_lapse, | ||
| const tnsr::iJ< DataVector, 3, Frame::Inertial > & | d_shift, | ||
| const tnsr::iJJ< DataVector, 3, Frame::Inertial > & | d_inv_spatial_metric, | ||
| const tnsr::ii< DataVector, 3, Frame::Inertial > & | spatial_metric, | ||
| const tnsr::II< DataVector, 3, Frame::Inertial > & | inv_spatial_metric, | ||
| const std::optional< tnsr::I< DataVector, 3, Frame::Inertial > > & | mesh_velocity, | ||
| const InverseJacobian< DataVector, 3, Frame::ElementLogical, Frame::Inertial > & | inverse_jacobian_logical_to_inertial, | ||
| const Jacobian< DataVector, 4, Frame::Inertial, Frame::Fluid > & | inertial_to_fluid_jacobian, | ||
| const InverseJacobian< DataVector, 4, Frame::Inertial, Frame::Fluid > & | inertial_to_fluid_inverse_jacobian | ||
| ) |
Evolve Monte-Carlo packets within an element.
Evolve packets until (approximately) the provided final time following the methods of [69]. The vector of Packets should contain all MC packets that we wish to advance in time. Note that this function only handles propagation / absorption / scattering of packets, but not emission. The final time of the packet may differ from the desired final time by up to 5 percent, due to the fact that when using the diffusion approximation (for large scattering opacities) we take fixed time steps in the fluid frame, leading to unpredictable time steps in the inertial frame.