// // ******************************************************************** // * License and Disclaimer * // * * // * The Geant4 software is copyright of the Copyright Holders of * // * the Geant4 Collaboration. It is provided under the terms and * // * conditions of the Geant4 Software License, included in the file * // * LICENSE and available at http://cern.ch/geant4/license . These * // * include a list of copyright holders. * // * * // * Neither the authors of this software system, nor their employing * // * institutes,nor the agencies providing financial support for this * // * work make any representation or warranty, express or implied, * // * regarding this software system or assume any liability for its * // * use. Please see the license in the file LICENSE and URL above * // * for the full disclaimer and the limitation of liability. * // * * // * This code implementation is the result of the scientific and * // * technical work of the GEANT4 collaboration. * // * By using, copying, modifying or distributing the software (or * // * any work based on the software) you agree to acknowledge its * // * use in resulting scientific publications, and indicate your * // * acceptance of all terms of the Geant4 Software license. * // ******************************************************************** // // // $Id: G4FinalStateElasticBrennerZaider.cc,v 1.1 2007/10/12 23:11:41 pia Exp $ // GEANT4 tag $Name: $ // // Contact Author: Maria Grazia Pia (Maria.Grazia.Pia@cern.ch) // // Reference: TNS Geant4-DNA paper // Reference for implementation model: NIM. 155, pp. 145-156, 1978 // History: // ----------- // Date Name Modification // 28 Apr 2007 M.G. Pia Created in compliance with design described in TNS paper // // ------------------------------------------------------------------- // Class description: // Reference: TNS Geant4-DNA paper // S. Chauvie et al., Geant4 physics processes for microdosimetry simulation: // design foundation and implementation of the first set of models, // IEEE Trans. Nucl. Sci., vol. 54, no. 6, Dec. 2007. // Further documentation available from http://www.ge.infn.it/geant4/dna // ------------------------------------------------------------------- #include "G4FinalStateElasticBrennerZaider.hh" #include "G4Track.hh" #include "G4Step.hh" #include "G4DynamicParticle.hh" #include "Randomize.hh" #include "G4ParticleTypes.hh" #include "G4ParticleDefinition.hh" #include "G4Electron.hh" #include "G4SystemOfUnits.hh" #include "G4ParticleMomentum.hh" G4FinalStateElasticBrennerZaider::G4FinalStateElasticBrennerZaider() { // These data members will be used in the next implementation iteration, // when the enriched PhysicsModel policy is implemented name = "FinalStateElasticBrennerZaider"; lowEnergyLimit = 7.4 * eV; highEnergyLimit = 10 * MeV; betaCoeff.push_back(7.51525); betaCoeff.push_back(-0.41912); betaCoeff.push_back(7.2017E-3); betaCoeff.push_back(-4.646E-5); betaCoeff.push_back(1.02897E-7); deltaCoeff.push_back(2.9612); deltaCoeff.push_back(-0.26376); deltaCoeff.push_back(4.307E-3); deltaCoeff.push_back(-2.6895E-5); deltaCoeff.push_back(5.83505E-8); gamma035_10Coeff.push_back(-1.7013); gamma035_10Coeff.push_back(-1.48284); gamma035_10Coeff.push_back(0.6331); gamma035_10Coeff.push_back(-0.10911); gamma035_10Coeff.push_back(8.358E-3); gamma035_10Coeff.push_back(-2.388E-4); gamma10_100Coeff.push_back(-3.32517); gamma10_100Coeff.push_back(0.10996); gamma10_100Coeff.push_back(-4.5255E-3); gamma10_100Coeff.push_back(5.8372E-5); gamma10_100Coeff.push_back(-2.4659E-7); gamma100_200Coeff.push_back(2.4775E-2); gamma100_200Coeff.push_back(-2.96264E-5); gamma100_200Coeff.push_back(-1.20655E-7); } G4FinalStateElasticBrennerZaider::~G4FinalStateElasticBrennerZaider() { // empty // G4DynamicParticle objects produced are owned by client } const G4FinalStateProduct& G4FinalStateElasticBrennerZaider::GenerateFinalState(const G4Track& track, const G4Step& /* step */) { // Clear previous secondaries, energy deposit and particle kill status product.Clear(); // Kinetic energy of primary particle G4double k = track.GetDynamicParticle()->GetKineticEnergy(); // Assume material = water; H2O number of electrons // ---- MGP ---- To be generalized later // const G4int z = 10; G4double cosTheta = RandomizeCosTheta(k); G4double phi = 2. * pi * G4UniformRand(); // G4cout << "cosTheta in GenerateFinalState = " << cosTheta << ", phi = " << phi << G4endl; G4ThreeVector zVers = track.GetDynamicParticle()->GetMomentumDirection(); G4ThreeVector xVers = zVers.orthogonal(); G4ThreeVector yVers = zVers.cross(xVers); G4double xDir = std::sqrt(1. - cosTheta*cosTheta); G4double yDir = xDir; xDir *= std::cos(phi); yDir *= std::sin(phi); // G4cout << "xDir, yDir = " << xDir <<", " << yDir << G4endl; // G4ThreeVector zPrimeVers((xDir*xVers + yDir*yVers + cosTheta*zVers).unit()); G4ThreeVector zPrimeVers((xDir*xVers + yDir*yVers + cosTheta*zVers)); // G4cout << "zPrimeVers = (" << zPrimeVers.x() << ", "<< zPrimeVers.y() << ", "<< zPrimeVers.z() << ") " << G4endl; // product.ModifyPrimaryParticle(zPrimeVers.x(),zPrimeVers.y(),zPrimeVers.z(),k); product.ModifyPrimaryParticle(zPrimeVers,k); // this->aParticleChange.ProposeEnergy(k); // this->aParticleChange.ProposeMomentumDirection(zPrimeVers); // this->aParticleChange.SetNumberOfSecondaries(0); return product; } G4double G4FinalStateElasticBrennerZaider::RandomizeCosTheta(G4double k) { // d sigma_el 1 beta(K) // ------------ (K) ~ --------------------------------- + --------------------------------- // d Omega (1 + 2 gamma(K) - cos(theta))^2 (1 + 2 delta(K) + cos(theta))^2 // // Maximum is < 1/(4 gamma(K)^2) + beta(K)/(4 delta(K)^2) // // Phys. Med. Biol. 29 N.4 (1983) 443-447 // gamma(K), beta(K) and delta(K) are polynomials with coefficients for energy measured in eV k /= eV; G4double beta = std::exp(CalculatePolynomial(k,betaCoeff)); G4double delta = std::exp(CalculatePolynomial(k,deltaCoeff)); G4double gamma; if (k > 100.) { gamma = CalculatePolynomial(k, gamma100_200Coeff); // Only in this case it is not the exponent of the polynomial } else { if (k>10) { gamma = std::exp(CalculatePolynomial(k, gamma10_100Coeff)); } else { gamma = std::exp(CalculatePolynomial(k, gamma035_10Coeff)); } } // G4cout << "beta = " << beta << ", gamma = " << gamma << ", delta = " << delta << G4endl; G4double oneOverMax = 1. / (1./(4.*gamma*gamma) + beta/(4.*delta*delta)); G4double cosTheta = 0.; G4double leftDenominator = 0.; G4double rightDenominator = 0.; G4double fCosTheta = 0.; do { cosTheta = 2. * G4UniformRand() - 1.; leftDenominator = (1 + 2.*gamma - cosTheta); rightDenominator = (1 + 2.*delta + cosTheta); fCosTheta = oneOverMax * (1./(leftDenominator*leftDenominator) + beta/(rightDenominator*rightDenominator)); } while (fCosTheta < G4UniformRand()); // G4cout << "cosTheta = " << cosTheta << G4endl; return cosTheta; } G4double G4FinalStateElasticBrennerZaider::CalculatePolynomial(G4double k, std::vector& vec) { // Sum_{i=0}^{size-1} vector_i k^i // // Phys. Med. Biol. 29 N.4 (1983) 443-447 G4double result = 0.; size_t size = vec.size(); while (size>0) { size--; result *= k; result += vec[size]; } return result; }