forked from celeritas-project/celeritas
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Merge branch 'develop' into googletest-xml-fix
- Loading branch information
Showing
37 changed files
with
1,406 additions
and
588 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file was deleted.
Oops, something went wrong.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
132 changes: 132 additions & 0 deletions
132
src/celeritas/em/distribution/BetheBlochEnergyDistribution.hh
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,132 @@ | ||
| //----------------------------------*-C++-*----------------------------------// | ||
| // Copyright 2024 UT-Battelle, LLC, and other Celeritas developers. | ||
| // See the top-level COPYRIGHT file for details. | ||
| // SPDX-License-Identifier: (Apache-2.0 OR MIT) | ||
| //---------------------------------------------------------------------------// | ||
| //! \file celeritas/em/distribution/BetheBlochEnergyDistribution.hh | ||
| //---------------------------------------------------------------------------// | ||
| #pragma once | ||
|
|
||
| #include <cmath> | ||
|
|
||
| #include "corecel/Macros.hh" | ||
| #include "corecel/Types.hh" | ||
| #include "corecel/math/Algorithms.hh" | ||
| #include "celeritas/Constants.hh" | ||
| #include "celeritas/Quantities.hh" | ||
| #include "celeritas/phys/ParticleTrackView.hh" | ||
| #include "celeritas/random/distribution/InverseSquareDistribution.hh" | ||
| #include "celeritas/random/distribution/RejectionSampler.hh" | ||
|
|
||
| #include "detail/Utils.hh" | ||
|
|
||
| namespace celeritas | ||
| { | ||
| //---------------------------------------------------------------------------// | ||
| /*! | ||
| * Sample the energy of the delta ray for muon or hadron ionization. | ||
| * | ||
| * This samples the energy according to the Bethe-Bloch model, as described in | ||
| * the Geant4 Physics Reference Manual release 11.2 section 12.1.5. The | ||
| * Bethe-Bloch differential cross section can be written as | ||
| * \f[ | ||
| \difd{\sigma}{T} = 2\pi r_e^2 mc^2 Z \frac{z_p^2}{\beta^2}\frac{1}{T^2} | ||
| \left[1 - \beta^2 \frac{T}{T_{max}} + s \frac{T^2}{2E^2} \right] | ||
| * \f] | ||
| * and factorized as | ||
| * \f[ | ||
| \difd{\sigma}{T} = C f(T) g(T) | ||
| * \f] | ||
| * with \f$ T \in [T_{cut}, T_{max}] \f$, where \f$ f(T) = \frac{1}{T^2} \f$, | ||
| * \f$ g(T) = 1 - \beta^2 \frac{T}{T_max} + s \frac{T^2}{2 E^2} \f$, \f$ T \f$ | ||
| * is the kinetic energy of the electron, \f$ E \f$ is the total energy of the | ||
| * incident particle, and \f$ s \f$ is 0 for spinless particles and 1 | ||
| * otherwise. The energy is sampled from \f$ f(T) \f$ and accepted with | ||
| * probability \f$ g(T) \f$. | ||
| */ | ||
| class BetheBlochEnergyDistribution | ||
| { | ||
| public: | ||
| //!@{ | ||
| //! \name Type aliases | ||
| using Energy = units::MevEnergy; | ||
| using Mass = units::MevMass; | ||
| //!@} | ||
|
|
||
| public: | ||
| // Construct with incident and exiting particle data | ||
| inline CELER_FUNCTION | ||
| BetheBlochEnergyDistribution(ParticleTrackView const& particle, | ||
| Energy electron_cutoff, | ||
| Mass electron_mass); | ||
|
|
||
| // Sample the exiting energy | ||
| template<class Engine> | ||
| inline CELER_FUNCTION Energy operator()(Engine& rng); | ||
|
|
||
| //! Minimum energy of the secondary electron [MeV]. | ||
| CELER_FUNCTION Energy min_secondary_energy() const { return min_energy_; } | ||
|
|
||
| //! Maximum energy of the secondary electron [MeV]. | ||
| CELER_FUNCTION Energy max_secondary_energy() const { return max_energy_; } | ||
|
|
||
| private: | ||
| // Incident partcle mass | ||
| real_type inc_mass_; | ||
| // Square of fractional speed of light for incident particle | ||
| real_type beta_sq_; | ||
| // Minimum energy of the secondary electron [MeV] | ||
| Energy min_energy_; | ||
| // Maximum energy of the secondary electron [MeV] | ||
| Energy max_energy_; | ||
| }; | ||
|
|
||
| //---------------------------------------------------------------------------// | ||
| // INLINE DEFINITIONS | ||
| //---------------------------------------------------------------------------// | ||
| /*! | ||
| * Construct with incident and exiting particle data. | ||
| */ | ||
| CELER_FUNCTION | ||
| BetheBlochEnergyDistribution::BetheBlochEnergyDistribution( | ||
| ParticleTrackView const& particle, | ||
| Energy electron_cutoff, | ||
| Mass electron_mass) | ||
| : inc_mass_(value_as<Mass>(particle.mass())) | ||
| , beta_sq_(particle.beta_sq()) | ||
| , min_energy_(electron_cutoff) | ||
| , max_energy_(detail::calc_max_secondary_energy(particle, electron_mass)) | ||
| { | ||
| } | ||
|
|
||
| //---------------------------------------------------------------------------// | ||
| /*! | ||
| * Sample secondary electron energy. | ||
| */ | ||
| template<class Engine> | ||
| CELER_FUNCTION auto BetheBlochEnergyDistribution::operator()(Engine& rng) | ||
| -> Energy | ||
| { | ||
| InverseSquareDistribution sample_energy(value_as<Energy>(min_energy_), | ||
| value_as<Energy>(max_energy_)); | ||
| real_type energy; | ||
| do | ||
| { | ||
| // Sample 1/E^2 from Emin to Emax | ||
| energy = sample_energy(rng); | ||
| /*! | ||
| * \todo Adjust rejection functions if particle has positive spin | ||
| */ | ||
| } while (RejectionSampler<>( | ||
| 1 - (beta_sq_ / value_as<Energy>(max_energy_)) * energy)(rng)); | ||
|
|
||
| /*! | ||
| * \todo For hadrons, suppress high energy delta ray production with the | ||
| * projectile form factor | ||
| */ | ||
|
|
||
| return Energy{energy}; | ||
| } | ||
|
|
||
| //---------------------------------------------------------------------------// | ||
| } // namespace celeritas |
Oops, something went wrong.