Gabriele Cosmo
384 lines
14 KiB
C++
384 lines
14 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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// $Id: G4ePolarizedIonisation.cc 105740 2017-08-16 13:05:44Z gcosmo $
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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: G4ePolarizedIonisation
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//
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// Author: A.Schaelicke on base of Vladimir Ivanchenko code
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//
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// Creation date: 10.11.2005
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//
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// Modifications:
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//
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// 10-11-05, include polarization description (A.Schaelicke)
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// , create asymmetry table and determine interactionlength
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// , update polarized differential cross section
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//
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// 20-08-06, modified interface (A.Schaelicke)
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// 11-06-07, add PostStepGetPhysicalInteractionLength (A.Schalicke)
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//
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// Class Description:
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//
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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#include "G4ePolarizedIonisation.hh"
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#include "G4Electron.hh"
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#include "G4UniversalFluctuation.hh"
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#include "G4UnitsTable.hh"
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#include "G4PolarizedMollerBhabhaModel.hh"
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#include "G4PhysicsTableHelper.hh"
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#include "G4ProductionCutsTable.hh"
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#include "G4PolarizationManager.hh"
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#include "G4PolarizationHelper.hh"
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#include "G4StokesVector.hh"
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#include "G4EmParameters.hh"
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#include "G4SystemOfUnits.hh"
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4ePolarizedIonisation::G4ePolarizedIonisation(const G4String& name)
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: G4VEnergyLossProcess(name),
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theElectron(G4Electron::Electron()),
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isElectron(true),
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isInitialised(false),
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theTargetPolarization(0.,0.,0.),
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theAsymmetryTable(nullptr),
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theTransverseAsymmetryTable(nullptr)
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{
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verboseLevel=0;
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SetProcessSubType(fIonisation);
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SetSecondaryParticle(theElectron);
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flucModel = nullptr;
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emModel = nullptr;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4ePolarizedIonisation::~G4ePolarizedIonisation()
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{
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CleanTables();
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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void G4ePolarizedIonisation::CleanTables()
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{
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if(theAsymmetryTable) {
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theAsymmetryTable->clearAndDestroy();
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delete theAsymmetryTable;
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theAsymmetryTable = nullptr;
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}
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if(theTransverseAsymmetryTable) {
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theTransverseAsymmetryTable->clearAndDestroy();
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delete theTransverseAsymmetryTable;
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theTransverseAsymmetryTable = nullptr;
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}
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double
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G4ePolarizedIonisation::MinPrimaryEnergy(const G4ParticleDefinition*,
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const G4Material*, G4double cut)
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{
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G4double x = cut;
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if(isElectron) { x += cut; }
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return x;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4bool G4ePolarizedIonisation::IsApplicable(const G4ParticleDefinition& p)
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{
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return (&p == G4Electron::Electron() || &p == G4Positron::Positron());
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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void G4ePolarizedIonisation::InitialiseEnergyLossProcess(
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const G4ParticleDefinition* part,
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const G4ParticleDefinition* /*part2*/)
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{
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if(!isInitialised) {
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if(part == G4Positron::Positron()) { isElectron = false; }
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if (!FluctModel()) { SetFluctModel(new G4UniversalFluctuation()); }
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flucModel = FluctModel();
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emModel = new G4PolarizedMollerBhabhaModel();
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SetEmModel(emModel);
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G4EmParameters* param = G4EmParameters::Instance();
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emModel->SetLowEnergyLimit(param->MinKinEnergy());
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emModel->SetHighEnergyLimit(param->MaxKinEnergy());
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AddEmModel(1, emModel, flucModel);
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isInitialised = true;
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}
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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void G4ePolarizedIonisation::PrintInfo()
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{}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double G4ePolarizedIonisation::GetMeanFreePath(const G4Track& track,
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G4double step,
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G4ForceCondition* cond)
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{
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// *** get unploarised mean free path from lambda table ***
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G4double mfp = G4VEnergyLossProcess::GetMeanFreePath(track, step, cond);
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if(theAsymmetryTable && theTransverseAsymmetryTable && mfp < DBL_MAX) {
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mfp *= ComputeSaturationFactor(track);
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}
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if (verboseLevel>=2) {
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G4cout << "G4ePolarizedIonisation::MeanFreePath: "
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<< mfp / mm << " mm " << G4endl;
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}
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return mfp;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double G4ePolarizedIonisation::PostStepGetPhysicalInteractionLength(const G4Track& track,
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G4double step,
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G4ForceCondition* cond)
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{
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// save previous values
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G4double nLength = theNumberOfInteractionLengthLeft;
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G4double iLength = currentInteractionLength;
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// *** get unpolarised mean free path from lambda table ***
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// this changes theNumberOfInteractionLengthLeft and currentInteractionLength
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G4double x = G4VEnergyLossProcess::PostStepGetPhysicalInteractionLength(track, step, cond);
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G4double x0 = x;
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G4double satFact = 1.;
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// *** add corrections on polarisation ***
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if(theAsymmetryTable && theTransverseAsymmetryTable && x < DBL_MAX) {
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satFact = ComputeSaturationFactor(track);
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G4double curLength = currentInteractionLength*satFact;
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G4double prvLength = iLength*satFact;
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if(nLength > 0.0) {
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theNumberOfInteractionLengthLeft =
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std::max(nLength - step/prvLength, 0.0);
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}
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x = theNumberOfInteractionLengthLeft * curLength;
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}
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if (verboseLevel>=2) {
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G4cout << "G4ePolarizedIonisation::PostStepGPIL: "
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<< std::setprecision(8) << x/mm << " mm;" << G4endl
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<< " unpolarized value: "
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<< std::setprecision(8) << x0/mm << " mm." << G4endl;
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}
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return x;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double
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G4ePolarizedIonisation::ComputeSaturationFactor(const G4Track& track)
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{
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G4Material* aMaterial = track.GetMaterial();
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G4VPhysicalVolume* aPVolume = track.GetVolume();
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G4LogicalVolume* aLVolume = aPVolume->GetLogicalVolume();
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G4PolarizationManager * polarizationManger = G4PolarizationManager::GetInstance();
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const G4bool volumeIsPolarized = polarizationManger->IsPolarized(aLVolume);
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G4StokesVector volPolarization = polarizationManger->GetVolumePolarization(aLVolume);
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G4double factor = 1.0;
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if (volumeIsPolarized && !volPolarization.IsZero()) {
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// *** get asymmetry, if target is polarized ***
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const G4DynamicParticle* aDynamicPart = track.GetDynamicParticle();
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const G4double energy = aDynamicPart->GetKineticEnergy();
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const G4StokesVector polarization = track.GetPolarization();
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const G4ParticleMomentum direction0 = aDynamicPart->GetMomentumDirection();
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if (verboseLevel>=2) {
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G4cout << "G4ePolarizedIonisation::ComputeSaturationFactor: " << G4endl;
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G4cout << " Energy(MeV) " << energy/MeV << G4endl;
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G4cout << " Direction " << direction0 << G4endl;
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G4cout << " Polarization " << polarization << G4endl;
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G4cout << " MaterialPol. " << volPolarization << G4endl;
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G4cout << " Phys. Volume " << aPVolume->GetName() << G4endl;
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G4cout << " Log. Volume " << aLVolume->GetName() << G4endl;
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G4cout << " Material " << aMaterial << G4endl;
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}
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size_t midx = CurrentMaterialCutsCoupleIndex();
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const G4PhysicsVector* aVector = nullptr;
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const G4PhysicsVector* bVector = nullptr;
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if(midx < theAsymmetryTable->size()) {
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aVector = (*theAsymmetryTable)(midx);
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}
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if(midx < theTransverseAsymmetryTable->size()) {
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bVector = (*theTransverseAsymmetryTable)(midx);
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}
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if(aVector && bVector) {
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G4double lAsymmetry = aVector->Value(energy);
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G4double tAsymmetry = bVector->Value(energy);
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G4double polZZ = polarization.z()*(volPolarization*direction0);
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G4double polXX = polarization.x()*
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(volPolarization*G4PolarizationHelper::GetParticleFrameX(direction0));
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G4double polYY = polarization.y()*
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(volPolarization*G4PolarizationHelper::GetParticleFrameY(direction0));
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factor /= (1. + polZZ*lAsymmetry + (polXX + polYY)*tAsymmetry);
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if (verboseLevel>=2) {
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G4cout << " Asymmetry: " << lAsymmetry << ", " << tAsymmetry << G4endl;
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G4cout << " PolProduct: " << polXX << ", " << polYY << ", " << polZZ << G4endl;
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G4cout << " Factor: " << factor << G4endl;
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}
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} else {
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G4ExceptionDescription ed;
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ed << "Problem with asymmetry tables: material index " << midx
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<< " is out of range or tables are not filled";
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G4Exception("G4ePolarizedIonisation::ComputeSaturationFactor","em0048",
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JustWarning, ed, "");
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}
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}
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return factor;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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void G4ePolarizedIonisation::BuildPhysicsTable(
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const G4ParticleDefinition& part)
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{
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// *** build DEDX and (unpolarized) cross section tables
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G4VEnergyLossProcess::BuildPhysicsTable(part);
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G4bool master = true;
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const G4ePolarizedIonisation* masterProcess =
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static_cast<const G4ePolarizedIonisation*>(GetMasterProcess());
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if(masterProcess && masterProcess != this) { master = false; }
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if(master) { BuildAsymmetryTables(part); }
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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void G4ePolarizedIonisation::BuildAsymmetryTables(
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const G4ParticleDefinition& part)
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{
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// cleanup old, initialise new table
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CleanTables();
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theAsymmetryTable =
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G4PhysicsTableHelper::PreparePhysicsTable(theAsymmetryTable);
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theTransverseAsymmetryTable =
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G4PhysicsTableHelper::PreparePhysicsTable(theTransverseAsymmetryTable);
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const G4ProductionCutsTable* theCoupleTable=
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G4ProductionCutsTable::GetProductionCutsTable();
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size_t numOfCouples = theCoupleTable->GetTableSize();
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for (size_t j=0 ; j < numOfCouples; j++ ) {
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// get cut value
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const G4MaterialCutsCouple* couple = theCoupleTable->GetMaterialCutsCouple(j);
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G4double cut = (*theCoupleTable->GetEnergyCutsVector(1))[j];
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//create physics vectors then fill it (same parameters as lambda vector)
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G4PhysicsVector * ptrVectorA = LambdaPhysicsVector(couple,cut);
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G4PhysicsVector * ptrVectorB = LambdaPhysicsVector(couple,cut);
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size_t bins = ptrVectorA->GetVectorLength();
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for (size_t i = 0 ; i < bins ; i++ ) {
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G4double lowEdgeEnergy = ptrVectorA->Energy(i);
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G4double tasm=0.;
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G4double asym = ComputeAsymmetry(lowEdgeEnergy, couple, part, cut, tasm);
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ptrVectorA->PutValue(i,asym);
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ptrVectorB->PutValue(i,tasm);
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}
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theAsymmetryTable->insertAt( j , ptrVectorA ) ;
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theTransverseAsymmetryTable->insertAt( j , ptrVectorB ) ;
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}
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double
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G4ePolarizedIonisation::ComputeAsymmetry(G4double energy,
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const G4MaterialCutsCouple* couple,
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const G4ParticleDefinition& aParticle,
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G4double cut,
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G4double & tAsymmetry)
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{
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G4double lAsymmetry = 0.0;
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tAsymmetry = 0.0;
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if (isElectron) { lAsymmetry = tAsymmetry = -1.0; }
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// calculate polarized cross section
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theTargetPolarization=G4ThreeVector(0.,0.,1.);
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emModel->SetTargetPolarization(theTargetPolarization);
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emModel->SetBeamPolarization(theTargetPolarization);
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G4double sigma2=emModel->CrossSection(couple,&aParticle,energy,cut,energy);
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// calculate transversely polarized cross section
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theTargetPolarization=G4ThreeVector(1.,0.,0.);
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emModel->SetTargetPolarization(theTargetPolarization);
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emModel->SetBeamPolarization(theTargetPolarization);
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G4double sigma3=emModel->CrossSection(couple,&aParticle,energy,cut,energy);
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// calculate unpolarized cross section
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theTargetPolarization=G4ThreeVector();
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emModel->SetTargetPolarization(theTargetPolarization);
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emModel->SetBeamPolarization(theTargetPolarization);
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G4double sigma0 = emModel->CrossSection(couple,&aParticle,energy,cut,energy);
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// determine assymmetries
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if (sigma0 > 0.) {
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lAsymmetry=sigma2/sigma0 - 1.;
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tAsymmetry=sigma3/sigma0 - 1.;
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}
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if (std::fabs(lAsymmetry)>1.) {
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G4cout<<"G4ePolarizedIonisation::ComputeAsymmetry WARNING: E(MeV)= "
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<< energy << " lAsymmetry= "<<lAsymmetry
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<<" ("<<std::fabs(lAsymmetry)-1.<<")\n";
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}
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if (std::fabs(tAsymmetry)>1.) {
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G4cout<<" energy="<<energy<<"\n";
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G4cout<<"G4ePolarizedIonisation::ComputeAsymmetry WARNING: E(MeV)= "
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<< energy << " tAsymmetry= "<<tAsymmetry
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<<" ("<<std::fabs(tAsymmetry)-1.<<")\n";
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}
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return lAsymmetry;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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