121 lines
4.7 KiB
C++
121 lines
4.7 KiB
C++
//
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// ********************************************************************
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// * License and Disclaimer *
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// * *
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// * The Geant4 software is copyright of the Copyright Holders of *
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// * the Geant4 Collaboration. It is provided under the terms and *
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// * conditions of the Geant4 Software License, included in the file *
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// * LICENSE and available at http://cern.ch/geant4/license . These *
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// * include a list of copyright holders. *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. Please see the license in the file LICENSE and URL above *
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// * for the full disclaimer and the limitation of liability. *
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// * *
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// * This code implementation is the result of the scientific and *
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// * technical work of the GEANT4 collaboration. *
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// * By using, copying, modifying or distributing the software (or *
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// * any work based on the software) you agree to acknowledge its *
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// * use in resulting scientific publications, and indicate your *
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// * acceptance of all terms of the Geant4 Software license. *
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// ********************************************************************
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//
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//
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// -------------------------------------------------------------------
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//
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// GEANT4 Class file
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//
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//
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// File name: G4PhotoElectricAngularGeneratorSauterGavrila
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//
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// Creation date: 10 May 2004
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//
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// Modifications:
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// 10 May 2003 P. Rodrigues First implementation acording with new design
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//
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// Class Description:
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//
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// Concrete class for PhotoElectric Electron Angular Distribution Generation
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// This model is a re-implementation of the Photolectric angular distribution
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// developed my M. Maire for the Standard EM Physics G4PhotoElectricEffect
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//
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// Class Description: End
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//
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// -------------------------------------------------------------------
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//
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//
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#include "G4PhotoElectricAngularGeneratorSauterGavrila.hh"
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#include "Randomize.hh"
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//
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G4PhotoElectricAngularGeneratorSauterGavrila::G4PhotoElectricAngularGeneratorSauterGavrila(const G4String& name):
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G4VPhotoElectricAngularDistribution(name)
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{;}
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//
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G4PhotoElectricAngularGeneratorSauterGavrila::~G4PhotoElectricAngularGeneratorSauterGavrila()
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{;}
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//
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G4ThreeVector G4PhotoElectricAngularGeneratorSauterGavrila::GetPhotoElectronDirection(const G4ThreeVector& direction,
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const G4double eKineticEnergy,
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const G4ThreeVector&, const G4int) const
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{
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// Compute Theta distribution of the emitted electron, with respect to the
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// incident Gamma.
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// The Sauter-Gavrila distribution for the K-shell is used. (adapted from G4PhotoElectricEffect)
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G4double costeta = 1.;
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G4double Phi = twopi * G4UniformRand();
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G4double cosphi = std::cos(Phi);
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G4double sinphi = std::sin(Phi);
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G4double sinteta = 0;
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G4double gamma = 1. + eKineticEnergy/electron_mass_c2;
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if (gamma > 5.) {
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G4ThreeVector outdirection (sinteta*cosphi, sinteta*sinphi, costeta);
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return outdirection;
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// Bugzilla 1120
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// SI on 05/09/2010 as suggested by JG 04/09/10
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}
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G4double beta = std::sqrt(gamma*gamma-1.)/gamma;
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G4double b = 0.5*gamma*(gamma-1.)*(gamma-2);
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G4double rndm,term,greject,grejsup;
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if (gamma < 2.) grejsup = gamma*gamma*(1.+b-beta*b);
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else grejsup = gamma*gamma*(1.+b+beta*b);
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do { rndm = 1.-2*G4UniformRand();
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costeta = (rndm+beta)/(rndm*beta+1.);
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term = 1.-beta*costeta;
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greject = (1.-costeta*costeta)*(1.+b*term)/(term*term);
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} while(greject < G4UniformRand()*grejsup);
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sinteta = std::sqrt(1.-costeta*costeta);
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G4ThreeVector photoelectrondirection (sinteta*cosphi, sinteta*sinphi, costeta);
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photoelectrondirection.rotateUz(direction);
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return photoelectrondirection;
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}
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//
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void G4PhotoElectricAngularGeneratorSauterGavrila::PrintGeneratorInformation() const
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{
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G4cout << "\n" << G4endl;
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G4cout << "" << G4endl;
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G4cout << "Re-implementation of the photolectric angular distribution" << G4endl;
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G4cout << "developed my M. Maire for the Standard EM Physics G4PhotoElectricEffect" << G4endl;
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G4cout << "It computes the theta distribution of the emitted electron, with respect to the" << G4endl;
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G4cout << "incident Gamma, using the Sauter-Gavrila distribution for the K-shell\n" << G4endl;
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}
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