Gabriele Cosmo
1268 lines
45 KiB
C++
1268 lines
45 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: G4UrbanMscModel
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//
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// Author: Laszlo Urban
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//
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// Creation date: 19.02.2013
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//
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// Created from G4UrbanMscModel96
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//
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// New parametrization for theta0
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// Correction for very small step length
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//
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// Class Description:
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//
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// Implementation of the model of multiple scattering based on
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// H.W.Lewis Phys Rev 78 (1950) 526 and others
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// -------------------------------------------------------------------
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// In its present form the model can be used for simulation
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// of the e-/e+ multiple scattering
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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 "G4UrbanMscModel.hh"
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#include "G4PhysicalConstants.hh"
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#include "G4SystemOfUnits.hh"
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#include "Randomize.hh"
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#include "G4Positron.hh"
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#include "G4EmParameters.hh"
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#include "G4ParticleChangeForMSC.hh"
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#include "G4ProductionCutsTable.hh"
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#include "G4Poisson.hh"
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#include "G4Pow.hh"
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#include "G4Log.hh"
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#include "G4Exp.hh"
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#include "G4AutoLock.hh"
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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std::vector<G4UrbanMscModel::mscData*> G4UrbanMscModel::msc;
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namespace
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{
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G4Mutex theUrbanMutex = G4MUTEX_INITIALIZER;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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G4UrbanMscModel::G4UrbanMscModel(const G4String& nam)
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: G4VMscModel(nam)
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{
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masslimite = 0.6*CLHEP::MeV;
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fr = 0.02;
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taubig = 8.0;
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tausmall = 1.e-16;
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taulim = 1.e-6;
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currentTau = taulim;
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tlimitminfix = 0.01*CLHEP::nm;
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tlimitminfix2 = 1.*CLHEP::nm;
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stepmin = tlimitminfix;
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smallstep = 1.e10;
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currentRange = 0. ;
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rangeinit = 0.;
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tlimit = 1.e10*CLHEP::mm;
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tlimitmin = 10.*tlimitminfix;
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tgeom = 1.e50*CLHEP::mm;
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geombig = tgeom;
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geommin = 1.e-3*CLHEP::mm;
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geomlimit = geombig;
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presafety = 0.*CLHEP::mm;
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particle = nullptr;
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positron = G4Positron::Positron();
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rndmEngineMod = G4Random::getTheEngine();
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firstStep = true;
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insideskin = false;
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latDisplasmentbackup = false;
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dispAlg96 = true;
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rangecut = geombig;
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drr = 0.35;
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finalr = 10.*CLHEP::um;
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tlow = 5.*CLHEP::keV;
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invmev = 1.0/CLHEP::MeV;
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skindepth = skin*stepmin;
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mass = CLHEP::proton_mass_c2;
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charge = chargeSquare = 1.0;
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currentKinEnergy = currentRadLength = lambda0 = lambdaeff = tPathLength
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= zPathLength = par1 = par2 = par3 = rndmarray[0] = rndmarray[1] = 0;
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currentLogKinEnergy = LOG_EKIN_MIN;
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idx = 0;
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fParticleChange = nullptr;
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couple = nullptr;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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G4UrbanMscModel::~G4UrbanMscModel()
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{
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if(isFirstInstance) {
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for(auto & ptr : msc) { delete ptr; }
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msc.clear();
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}
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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void G4UrbanMscModel::Initialise(const G4ParticleDefinition* p,
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const G4DataVector&)
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{
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// set values of some data members
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SetParticle(p);
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fParticleChange = GetParticleChangeForMSC(p);
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InitialiseParameters(p);
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latDisplasmentbackup = latDisplasment;
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dispAlg96 = (G4EmParameters::Instance()->LateralDisplacementAlg96());
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// initialise cache only once
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if(0 == msc.size()) {
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G4AutoLock l(&theUrbanMutex);
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if(0 == msc.size()) {
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isFirstInstance = true;
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msc.resize(1, nullptr);
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}
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l.unlock();
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}
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// initialise cache for each new run
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if(isFirstInstance) { InitialiseModelCache(); }
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/*
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G4cout << "### G4UrbanMscModel::Initialise done for "
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<< p->GetParticleName() << " type= " << steppingAlgorithm << G4endl;
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G4cout << " RangeFact= " << facrange << " GeomFact= " << facgeom
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<< " SafetyFact= " << facsafety << " LambdaLim= " << lambdalimit
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<< G4endl;
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*/
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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G4double G4UrbanMscModel::ComputeCrossSectionPerAtom(
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const G4ParticleDefinition* part,
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G4double kinEnergy,
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G4double atomicNumber,G4double,
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G4double, G4double)
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{
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static const G4double epsmin = 1.e-4 , epsmax = 1.e10;
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static const G4double Zdat[15] = { 4., 6., 13., 20., 26., 29., 32., 38.,47.,
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50., 56., 64., 74., 79., 82. };
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// corr. factors for e-/e+ lambda for T <= Tlim
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static const G4double celectron[15][22] =
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{{1.125,1.072,1.051,1.047,1.047,1.050,1.052,1.054,
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1.054,1.057,1.062,1.069,1.075,1.090,1.105,1.111,
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1.112,1.108,1.100,1.093,1.089,1.087 },
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{1.408,1.246,1.143,1.096,1.077,1.059,1.053,1.051,
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1.052,1.053,1.058,1.065,1.072,1.087,1.101,1.108,
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1.109,1.105,1.097,1.090,1.086,1.082 },
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{2.833,2.268,1.861,1.612,1.486,1.309,1.204,1.156,
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1.136,1.114,1.106,1.106,1.109,1.119,1.129,1.132,
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1.131,1.124,1.113,1.104,1.099,1.098 },
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{3.879,3.016,2.380,2.007,1.818,1.535,1.340,1.236,
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1.190,1.133,1.107,1.099,1.098,1.103,1.110,1.113,
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1.112,1.105,1.096,1.089,1.085,1.098 },
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{6.937,4.330,2.886,2.256,1.987,1.628,1.395,1.265,
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1.203,1.122,1.080,1.065,1.061,1.063,1.070,1.073,
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1.073,1.070,1.064,1.059,1.056,1.056 },
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{9.616,5.708,3.424,2.551,2.204,1.762,1.485,1.330,
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1.256,1.155,1.099,1.077,1.070,1.068,1.072,1.074,
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1.074,1.070,1.063,1.059,1.056,1.052 },
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{11.72,6.364,3.811,2.806,2.401,1.884,1.564,1.386,
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1.300,1.180,1.112,1.082,1.073,1.066,1.068,1.069,
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1.068,1.064,1.059,1.054,1.051,1.050 },
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{18.08,8.601,4.569,3.183,2.662,2.025,1.646,1.439,
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1.339,1.195,1.108,1.068,1.053,1.040,1.039,1.039,
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1.039,1.037,1.034,1.031,1.030,1.036 },
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{18.22,10.48,5.333,3.713,3.115,2.367,1.898,1.631,
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1.498,1.301,1.171,1.105,1.077,1.048,1.036,1.033,
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1.031,1.028,1.024,1.022,1.021,1.024 },
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{14.14,10.65,5.710,3.929,3.266,2.453,1.951,1.669,
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1.528,1.319,1.178,1.106,1.075,1.040,1.027,1.022,
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1.020,1.017,1.015,1.013,1.013,1.020 },
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{14.11,11.73,6.312,4.240,3.478,2.566,2.022,1.720,
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1.569,1.342,1.186,1.102,1.065,1.022,1.003,0.997,
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0.995,0.993,0.993,0.993,0.993,1.011 },
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{22.76,20.01,8.835,5.287,4.144,2.901,2.219,1.855,
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1.677,1.410,1.224,1.121,1.073,1.014,0.986,0.976,
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0.974,0.972,0.973,0.974,0.975,0.987 },
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{50.77,40.85,14.13,7.184,5.284,3.435,2.520,2.059,
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1.837,1.512,1.283,1.153,1.091,1.010,0.969,0.954,
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0.950,0.947,0.949,0.952,0.954,0.963 },
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{65.87,59.06,15.87,7.570,5.567,3.650,2.682,2.182,
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1.939,1.579,1.325,1.178,1.108,1.014,0.965,0.947,
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0.941,0.938,0.940,0.944,0.946,0.954 },
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{55.60,47.34,15.92,7.810,5.755,3.767,2.760,2.239,
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1.985,1.609,1.343,1.188,1.113,1.013,0.960,0.939,
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0.933,0.930,0.933,0.936,0.939,0.949 }};
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static const G4double cpositron[15][22] = {
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{2.589,2.044,1.658,1.446,1.347,1.217,1.144,1.110,
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1.097,1.083,1.080,1.086,1.092,1.108,1.123,1.131,
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1.131,1.126,1.117,1.108,1.103,1.100 },
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{3.904,2.794,2.079,1.710,1.543,1.325,1.202,1.145,
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1.122,1.096,1.089,1.092,1.098,1.114,1.130,1.137,
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1.138,1.132,1.122,1.113,1.108,1.102 },
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{7.970,6.080,4.442,3.398,2.872,2.127,1.672,1.451,
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1.357,1.246,1.194,1.179,1.178,1.188,1.201,1.205,
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1.203,1.190,1.173,1.159,1.151,1.145 },
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{9.714,7.607,5.747,4.493,3.815,2.777,2.079,1.715,
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1.553,1.353,1.253,1.219,1.211,1.214,1.225,1.228,
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1.225,1.210,1.191,1.175,1.166,1.174 },
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{17.97,12.95,8.628,6.065,4.849,3.222,2.275,1.820,
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1.624,1.382,1.259,1.214,1.202,1.202,1.214,1.219,
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1.217,1.203,1.184,1.169,1.160,1.151 },
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{24.83,17.06,10.84,7.355,5.767,3.707,2.546,1.996,
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1.759,1.465,1.311,1.252,1.234,1.228,1.238,1.241,
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1.237,1.222,1.201,1.184,1.174,1.159 },
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{23.26,17.15,11.52,8.049,6.375,4.114,2.792,2.155,
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1.880,1.535,1.353,1.281,1.258,1.247,1.254,1.256,
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1.252,1.234,1.212,1.194,1.183,1.170 },
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{22.33,18.01,12.86,9.212,7.336,4.702,3.117,2.348,
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2.015,1.602,1.385,1.297,1.268,1.251,1.256,1.258,
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1.254,1.237,1.214,1.195,1.185,1.179 },
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{33.91,24.13,15.71,10.80,8.507,5.467,3.692,2.808,
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2.407,1.873,1.564,1.425,1.374,1.330,1.324,1.320,
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1.312,1.288,1.258,1.235,1.221,1.205 },
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{32.14,24.11,16.30,11.40,9.015,5.782,3.868,2.917,
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2.490,1.925,1.596,1.447,1.391,1.342,1.332,1.327,
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1.320,1.294,1.264,1.240,1.226,1.214 },
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{29.51,24.07,17.19,12.28,9.766,6.238,4.112,3.066,
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2.602,1.995,1.641,1.477,1.414,1.356,1.342,1.336,
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1.328,1.302,1.270,1.245,1.231,1.233 },
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{38.19,30.85,21.76,15.35,12.07,7.521,4.812,3.498,
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2.926,2.188,1.763,1.563,1.484,1.405,1.382,1.371,
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1.361,1.330,1.294,1.267,1.251,1.239 },
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{49.71,39.80,27.96,19.63,15.36,9.407,5.863,4.155,
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3.417,2.478,1.944,1.692,1.589,1.480,1.441,1.423,
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1.409,1.372,1.330,1.298,1.280,1.258 },
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{59.25,45.08,30.36,20.83,16.15,9.834,6.166,4.407,
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3.641,2.648,2.064,1.779,1.661,1.531,1.482,1.459,
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1.442,1.400,1.354,1.319,1.299,1.272 },
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{56.38,44.29,30.50,21.18,16.51,10.11,6.354,4.542,
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3.752,2.724,2.116,1.817,1.692,1.554,1.499,1.474,
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1.456,1.412,1.364,1.328,1.307,1.282 }};
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//data/corrections for T > Tlim
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static const G4double hecorr[15] = {
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120.70, 117.50, 105.00, 92.92, 79.23, 74.510, 68.29,
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57.39, 41.97, 36.14, 24.53, 10.21, -7.855, -16.84,
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-22.30};
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G4double sigma;
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SetParticle(part);
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G4double Z23 = G4Pow::GetInstance()->Z23(G4lrint(atomicNumber));
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// correction if particle .ne. e-/e+
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// compute equivalent kinetic energy
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// lambda depends on p*beta ....
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G4double eKineticEnergy = kinEnergy;
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if(mass > CLHEP::electron_mass_c2)
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{
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G4double TAU = kinEnergy/mass ;
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G4double c = mass*TAU*(TAU+2.)/(CLHEP::electron_mass_c2*(TAU+1.)) ;
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G4double w = c-2.;
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G4double tau = 0.5*(w+std::sqrt(w*w+4.*c)) ;
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eKineticEnergy = CLHEP::electron_mass_c2*tau ;
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}
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G4double eTotalEnergy = eKineticEnergy + CLHEP::electron_mass_c2 ;
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G4double beta2 = eKineticEnergy*(eTotalEnergy+CLHEP::electron_mass_c2)
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/(eTotalEnergy*eTotalEnergy);
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G4double bg2 = eKineticEnergy*(eTotalEnergy+CLHEP::electron_mass_c2)
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/(CLHEP::electron_mass_c2*CLHEP::electron_mass_c2);
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static const G4double epsfactor = 2.*CLHEP::electron_mass_c2*
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CLHEP::electron_mass_c2*CLHEP::Bohr_radius*CLHEP::Bohr_radius
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/(CLHEP::hbarc*CLHEP::hbarc);
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G4double eps = epsfactor*bg2/Z23;
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if (eps<epsmin) sigma = 2.*eps*eps;
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else if(eps<epsmax) sigma = G4Log(1.+2.*eps)-2.*eps/(1.+2.*eps);
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else sigma = G4Log(2.*eps)-1.+1./eps;
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sigma *= chargeSquare*atomicNumber*atomicNumber/(beta2*bg2);
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// interpolate in AtomicNumber and beta2
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G4double c1,c2,cc1;
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// get bin number in Z
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G4int iZ = 14;
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// Loop checking, 03-Aug-2015, Vladimir Ivanchenko
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while ((iZ>=0)&&(Zdat[iZ]>=atomicNumber)) { --iZ; }
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iZ = std::min(std::max(iZ, 0), 13);
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G4double ZZ1 = Zdat[iZ];
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G4double ZZ2 = Zdat[iZ+1];
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G4double ratZ = (atomicNumber-ZZ1)*(atomicNumber+ZZ1)/
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((ZZ2-ZZ1)*(ZZ2+ZZ1));
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static const G4double Tlim = 10.*CLHEP::MeV;
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static const G4double sigmafactor =
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CLHEP::twopi*CLHEP::classic_electr_radius*CLHEP::classic_electr_radius;
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static const G4double beta2lim = Tlim*(Tlim+2.*CLHEP::electron_mass_c2)/
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((Tlim+CLHEP::electron_mass_c2)*(Tlim+CLHEP::electron_mass_c2));
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static const G4double bg2lim = Tlim*(Tlim+2.*CLHEP::electron_mass_c2)/
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(CLHEP::electron_mass_c2*CLHEP::electron_mass_c2);
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static const G4double sig0[15] = {
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0.2672*CLHEP::barn, 0.5922*CLHEP::barn, 2.653*CLHEP::barn, 6.235*CLHEP::barn,
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11.69*CLHEP::barn , 13.24*CLHEP::barn , 16.12*CLHEP::barn, 23.00*CLHEP::barn,
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35.13*CLHEP::barn , 39.95*CLHEP::barn , 50.85*CLHEP::barn, 67.19*CLHEP::barn,
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|
91.15*CLHEP::barn , 104.4*CLHEP::barn , 113.1*CLHEP::barn};
|
|
|
|
static const G4double Tdat[22] = {
|
|
100*CLHEP::eV, 200*CLHEP::eV, 400*CLHEP::eV, 700*CLHEP::eV,
|
|
1*CLHEP::keV, 2*CLHEP::keV, 4*CLHEP::keV, 7*CLHEP::keV,
|
|
10*CLHEP::keV, 20*CLHEP::keV, 40*CLHEP::keV, 70*CLHEP::keV,
|
|
100*CLHEP::keV, 200*CLHEP::keV, 400*CLHEP::keV, 700*CLHEP::keV,
|
|
1*CLHEP::MeV, 2*CLHEP::MeV, 4*CLHEP::MeV, 7*CLHEP::MeV,
|
|
10*CLHEP::MeV, 20*CLHEP::MeV};
|
|
|
|
if(eKineticEnergy <= Tlim)
|
|
{
|
|
// get bin number in T (beta2)
|
|
G4int iT = 21;
|
|
// Loop checking, 03-Aug-2015, Vladimir Ivanchenko
|
|
while ((iT>=0)&&(Tdat[iT]>=eKineticEnergy)) iT -= 1;
|
|
|
|
iT = std::min(std::max(iT, 0), 20);
|
|
|
|
// calculate betasquare values
|
|
G4double T = Tdat[iT];
|
|
G4double E = T + CLHEP::electron_mass_c2;
|
|
G4double b2small = T*(E+CLHEP::electron_mass_c2)/(E*E);
|
|
|
|
T = Tdat[iT+1];
|
|
E = T + CLHEP::electron_mass_c2;
|
|
G4double b2big = T*(E+CLHEP::electron_mass_c2)/(E*E);
|
|
G4double ratb2 = (beta2-b2small)/(b2big-b2small);
|
|
|
|
if (charge < 0.)
|
|
{
|
|
c1 = celectron[iZ][iT];
|
|
c2 = celectron[iZ+1][iT];
|
|
cc1 = c1+ratZ*(c2-c1);
|
|
|
|
c1 = celectron[iZ][iT+1];
|
|
c2 = celectron[iZ+1][iT+1];
|
|
}
|
|
else
|
|
{
|
|
c1 = cpositron[iZ][iT];
|
|
c2 = cpositron[iZ+1][iT];
|
|
cc1 = c1+ratZ*(c2-c1);
|
|
|
|
c1 = cpositron[iZ][iT+1];
|
|
c2 = cpositron[iZ+1][iT+1];
|
|
}
|
|
G4double cc2 = c1+ratZ*(c2-c1);
|
|
sigma *= sigmafactor/(cc1+ratb2*(cc2-cc1));
|
|
}
|
|
else
|
|
{
|
|
c1 = bg2lim*sig0[iZ]*(1.+hecorr[iZ]*(beta2-beta2lim))/bg2;
|
|
c2 = bg2lim*sig0[iZ+1]*(1.+hecorr[iZ+1]*(beta2-beta2lim))/bg2;
|
|
if((atomicNumber >= ZZ1) && (atomicNumber <= ZZ2))
|
|
sigma = c1+ratZ*(c2-c1) ;
|
|
else if(atomicNumber < ZZ1)
|
|
sigma = atomicNumber*atomicNumber*c1/(ZZ1*ZZ1);
|
|
else if(atomicNumber > ZZ2)
|
|
sigma = atomicNumber*atomicNumber*c2/(ZZ2*ZZ2);
|
|
}
|
|
// low energy correction based on theory
|
|
sigma *= (1.+0.30/(1.+std::sqrt(1000.*eKineticEnergy)));
|
|
|
|
return sigma;
|
|
}
|
|
|
|
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
|
|
|
|
void G4UrbanMscModel::StartTracking(G4Track* track)
|
|
{
|
|
SetParticle(track->GetDynamicParticle()->GetDefinition());
|
|
firstStep = true;
|
|
insideskin = false;
|
|
fr = facrange;
|
|
tlimit = tgeom = rangeinit = rangecut = geombig;
|
|
smallstep = 1.e10;
|
|
stepmin = tlimitminfix;
|
|
tlimitmin = 10.*tlimitminfix;
|
|
rndmEngineMod = G4Random::getTheEngine();
|
|
}
|
|
|
|
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
|
|
|
|
G4double G4UrbanMscModel::ComputeTruePathLengthLimit(
|
|
const G4Track& track,
|
|
G4double& currentMinimalStep)
|
|
{
|
|
tPathLength = currentMinimalStep;
|
|
const G4DynamicParticle* dp = track.GetDynamicParticle();
|
|
|
|
G4StepPoint* sp = track.GetStep()->GetPreStepPoint();
|
|
G4StepStatus stepStatus = sp->GetStepStatus();
|
|
couple = track.GetMaterialCutsCouple();
|
|
SetCurrentCouple(couple);
|
|
idx = couple->GetIndex();
|
|
currentKinEnergy = dp->GetKineticEnergy();
|
|
currentLogKinEnergy = dp->GetLogKineticEnergy();
|
|
currentRange = GetRange(particle,currentKinEnergy,couple,currentLogKinEnergy);
|
|
lambda0 = GetTransportMeanFreePath(particle,currentKinEnergy,
|
|
currentLogKinEnergy);
|
|
tPathLength = std::min(tPathLength,currentRange);
|
|
/*
|
|
G4cout << "G4Urban::StepLimit tPathLength= " << tPathLength
|
|
<< " range= " <<currentRange<< " lambda= "<<lambda0
|
|
<<G4endl;
|
|
*/
|
|
|
|
// stop here if small step
|
|
if(tPathLength < tlimitminfix) {
|
|
latDisplasment = false;
|
|
return ConvertTrueToGeom(tPathLength, currentMinimalStep);
|
|
}
|
|
|
|
// upper limit for the straight line distance the particle can travel
|
|
// for electrons and positrons
|
|
G4double distance = (mass < masslimite)
|
|
? currentRange*msc[idx]->doverra
|
|
// for muons, hadrons
|
|
: currentRange*msc[idx]->doverrb;
|
|
|
|
presafety = (stepStatus == fGeomBoundary) ? sp->GetSafety()
|
|
: ComputeSafety(sp->GetPosition(),tPathLength);
|
|
/*
|
|
G4cout << "G4Urban::StepLimit tPathLength= "
|
|
<<tPathLength<<" safety= " << presafety
|
|
<< " range= " <<currentRange<< " lambda= "<<lambda0
|
|
<< " Alg: " << steppingAlgorithm <<G4endl;
|
|
*/
|
|
// far from geometry boundary
|
|
if(distance < presafety)
|
|
{
|
|
latDisplasment = false;
|
|
return ConvertTrueToGeom(tPathLength, currentMinimalStep);
|
|
}
|
|
|
|
latDisplasment = latDisplasmentbackup;
|
|
// ----------------------------------------------------------------
|
|
// distance to boundary
|
|
if (steppingAlgorithm == fUseDistanceToBoundary)
|
|
{
|
|
//compute geomlimit and presafety
|
|
geomlimit = ComputeGeomLimit(track, presafety, currentRange);
|
|
/*
|
|
G4cout << "G4Urban::Distance to boundary geomlimit= "
|
|
<<geomlimit<<" safety= " << presafety<<G4endl;
|
|
*/
|
|
|
|
// is it far from boundary ?
|
|
if(distance < presafety)
|
|
{
|
|
latDisplasment = false;
|
|
return ConvertTrueToGeom(tPathLength, currentMinimalStep);
|
|
}
|
|
|
|
smallstep += 1.;
|
|
insideskin = false;
|
|
|
|
// initialisation at firs step and at the boundary
|
|
if(firstStep || (stepStatus == fGeomBoundary))
|
|
{
|
|
rangeinit = currentRange;
|
|
if(!firstStep) { smallstep = 1.; }
|
|
|
|
//stepmin ~ lambda_elastic
|
|
stepmin = ComputeStepmin();
|
|
skindepth = skin*stepmin;
|
|
tlimitmin = ComputeTlimitmin();
|
|
/*
|
|
G4cout << "rangeinit= " << rangeinit << " stepmin= " << stepmin
|
|
<< " tlimitmin= " << tlimitmin << " geomlimit= "
|
|
<< geomlimit <<G4endl;
|
|
*/
|
|
// constraint from the geometry
|
|
|
|
if((geomlimit < geombig) && (geomlimit > geommin))
|
|
{
|
|
// geomlimit is a geometrical step length
|
|
// transform it to true path length (estimation)
|
|
if(lambda0 > geomlimit) {
|
|
geomlimit = -lambda0*G4Log(1.-geomlimit/lambda0)+tlimitmin;
|
|
}
|
|
tgeom = (stepStatus == fGeomBoundary)
|
|
? geomlimit/facgeom : 2.*geomlimit/facgeom;
|
|
}
|
|
else
|
|
{
|
|
tgeom = geombig;
|
|
}
|
|
}
|
|
|
|
//step limit
|
|
tlimit = (currentRange > presafety) ?
|
|
std::max(facrange*rangeinit, facsafety*presafety) : currentRange;
|
|
|
|
//lower limit for tlimit
|
|
tlimit = std::min(std::max(tlimit,tlimitmin), tgeom);
|
|
/*
|
|
G4cout << "tgeom= " << tgeom << " geomlimit= " << geomlimit
|
|
<< " tlimit= " << tlimit << " presafety= " << presafety << G4endl;
|
|
*/
|
|
// shortcut
|
|
if((tPathLength < tlimit) && (tPathLength < presafety) &&
|
|
(smallstep > skin) && (tPathLength < geomlimit-0.999*skindepth))
|
|
{
|
|
return ConvertTrueToGeom(tPathLength, currentMinimalStep);
|
|
}
|
|
|
|
// step reduction near to boundary
|
|
if(smallstep <= skin)
|
|
{
|
|
tlimit = stepmin;
|
|
insideskin = true;
|
|
}
|
|
else if(geomlimit < geombig)
|
|
{
|
|
if(geomlimit > skindepth)
|
|
{
|
|
tlimit = std::min(tlimit, geomlimit-0.999*skindepth);
|
|
}
|
|
else
|
|
{
|
|
insideskin = true;
|
|
tlimit = std::min(tlimit, stepmin);
|
|
}
|
|
}
|
|
|
|
tlimit = std::max(tlimit, stepmin);
|
|
|
|
// randomise if not 'small' step and step determined by msc
|
|
tPathLength = ((tlimit < tPathLength)&&(smallstep > skin)&& !insideskin)
|
|
? std::min(tPathLength, Randomizetlimit())
|
|
: std::min(tPathLength, tlimit);
|
|
}
|
|
// ----------------------------------------------------------------
|
|
// for simulation with or without magnetic field
|
|
// there no small step/single scattering at boundaries
|
|
else if(steppingAlgorithm == fUseSafety)
|
|
{
|
|
// is far from boundary
|
|
if(distance < presafety)
|
|
{
|
|
latDisplasment = false;
|
|
return ConvertTrueToGeom(tPathLength, currentMinimalStep);
|
|
}
|
|
|
|
if(firstStep || (stepStatus == fGeomBoundary)) {
|
|
rangeinit = currentRange;
|
|
fr = facrange;
|
|
// stepping for e+/e- only (not for muons,hadrons)
|
|
if(mass < masslimite)
|
|
{
|
|
rangeinit = std::max(rangeinit, lambda0);
|
|
if(lambda0 > lambdalimit) {
|
|
fr *= (0.75+0.25*lambda0/lambdalimit);
|
|
}
|
|
}
|
|
//lower limit for tlimit
|
|
stepmin = ComputeStepmin();
|
|
tlimitmin = ComputeTlimitmin();
|
|
}
|
|
|
|
//step limit
|
|
tlimit = (currentRange > presafety) ?
|
|
std::max(fr*rangeinit, facsafety*presafety) : currentRange;
|
|
|
|
//lower limit for tlimit
|
|
tlimit = std::max(tlimit, tlimitmin);
|
|
|
|
// randomise if step determined by msc
|
|
tPathLength = (tlimit < tPathLength) ?
|
|
std::min(tPathLength, Randomizetlimit()) : tPathLength;
|
|
}
|
|
// ----------------------------------------------------------------
|
|
// for simulation with or without magnetic field
|
|
// there is small step/single scattering at boundaries
|
|
else if(steppingAlgorithm == fUseSafetyPlus)
|
|
{
|
|
// is far from boundary
|
|
if(distance < presafety)
|
|
{
|
|
latDisplasment = false;
|
|
return ConvertTrueToGeom(tPathLength, currentMinimalStep);
|
|
}
|
|
|
|
if(firstStep || (stepStatus == fGeomBoundary)) {
|
|
rangeinit = currentRange;
|
|
fr = facrange;
|
|
rangecut = geombig;
|
|
if(mass < masslimite)
|
|
{
|
|
rangecut = msc[idx]->ecut;
|
|
if(lambda0 > lambdalimit) {
|
|
fr *= (0.84+0.16*lambda0/lambdalimit);
|
|
}
|
|
}
|
|
//lower limit for tlimit
|
|
stepmin = ComputeStepmin();
|
|
tlimitmin = ComputeTlimitmin();
|
|
}
|
|
//step limit
|
|
tlimit = (currentRange > presafety) ?
|
|
std::max(fr*rangeinit, facsafety*presafety) : currentRange;
|
|
|
|
//lower limit for tlimit
|
|
tlimit = std::max(tlimit, tlimitmin);
|
|
|
|
// condition for tPathLength from drr and finalr
|
|
if(currentRange > finalr) {
|
|
G4double tmax = drr*currentRange+
|
|
finalr*(1.-drr)*(2.-finalr/currentRange);
|
|
tPathLength = std::min(tPathLength,tmax);
|
|
}
|
|
|
|
// condition safety
|
|
if(currentRange > rangecut) {
|
|
if(firstStep) {
|
|
tPathLength = std::min(tPathLength,facsafety*presafety);
|
|
} else if(stepStatus != fGeomBoundary && presafety > stepmin) {
|
|
tPathLength = std::min(tPathLength,presafety);
|
|
}
|
|
}
|
|
|
|
// randomise if step determined by msc
|
|
tPathLength = (tlimit < tPathLength) ?
|
|
std::min(tPathLength, Randomizetlimit()) : tPathLength;
|
|
}
|
|
|
|
// ----------------------------------------------------------------
|
|
// simple step limitation
|
|
else
|
|
{
|
|
if (stepStatus == fGeomBoundary)
|
|
{
|
|
tlimit = (currentRange > lambda0)
|
|
? facrange*currentRange : facrange*lambda0;
|
|
tlimit = std::max(tlimit, tlimitmin);
|
|
}
|
|
// randomise if step determined by msc
|
|
tPathLength = (tlimit < tPathLength) ?
|
|
std::min(tPathLength, Randomizetlimit()) : tPathLength;
|
|
}
|
|
|
|
// ----------------------------------------------------------------
|
|
firstStep = false;
|
|
return ConvertTrueToGeom(tPathLength, currentMinimalStep);
|
|
}
|
|
|
|
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
|
|
|
|
G4double G4UrbanMscModel::ComputeGeomPathLength(G4double)
|
|
{
|
|
lambdaeff = lambda0;
|
|
par1 = -1. ;
|
|
par2 = par3 = 0. ;
|
|
|
|
// this correction needed to run MSC with eIoni and eBrem inactivated
|
|
// and makes no harm for a normal run
|
|
tPathLength = std::min(tPathLength,currentRange);
|
|
|
|
// do the true -> geom transformation
|
|
zPathLength = tPathLength;
|
|
|
|
// z = t for very small tPathLength
|
|
if(tPathLength < tlimitminfix2) return zPathLength;
|
|
|
|
/*
|
|
G4cout << "ComputeGeomPathLength: tpl= " << tPathLength
|
|
<< " R= " << currentRange << " L0= " << lambda0
|
|
<< " E= " << currentKinEnergy << " "
|
|
<< particle->GetParticleName() << G4endl;
|
|
*/
|
|
G4double tau = tPathLength/lambda0 ;
|
|
|
|
if ((tau <= tausmall) || insideskin) {
|
|
zPathLength = std::min(tPathLength, lambda0);
|
|
|
|
} else if (tPathLength < currentRange*dtrl) {
|
|
if(tau < taulim) zPathLength = tPathLength*(1.-0.5*tau);
|
|
else zPathLength = lambda0*(1.-G4Exp(-tau));
|
|
|
|
} else if(currentKinEnergy < mass || tPathLength == currentRange) {
|
|
par1 = 1./currentRange;
|
|
par2 = currentRange/lambda0;
|
|
par3 = 1.+par2;
|
|
if(tPathLength < currentRange) {
|
|
zPathLength =
|
|
(1.-G4Exp(par3*G4Log(1.-tPathLength/currentRange)))/(par1*par3);
|
|
} else {
|
|
zPathLength = 1./(par1*par3);
|
|
}
|
|
|
|
} else {
|
|
G4double rfin = std::max(currentRange-tPathLength, 0.01*currentRange);
|
|
G4double T1 = GetEnergy(particle,rfin,couple);
|
|
G4double lambda1 = GetTransportMeanFreePath(particle,T1);
|
|
|
|
par1 = (lambda0-lambda1)/(lambda0*tPathLength);
|
|
//G4cout << "par1= " << par1 << " L1= " << lambda1 << G4endl;
|
|
par2 = 1./(par1*lambda0);
|
|
par3 = 1.+par2;
|
|
zPathLength = (1.-G4Exp(par3*G4Log(lambda1/lambda0)))/(par1*par3);
|
|
}
|
|
|
|
zPathLength = std::min(zPathLength, lambda0);
|
|
//G4cout<< "zPathLength= "<< zPathLength<< " L0= " << lambda0 << G4endl;
|
|
return zPathLength;
|
|
}
|
|
|
|
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
|
|
|
|
G4double G4UrbanMscModel::ComputeTrueStepLength(G4double geomStepLength)
|
|
{
|
|
// step defined other than transportation
|
|
if(geomStepLength == zPathLength) {
|
|
//G4cout << "Urban::ComputeTrueLength: tPathLength= " << tPathLength
|
|
// << " step= " << geomStepLength << " *** " << G4endl;
|
|
return tPathLength;
|
|
}
|
|
|
|
zPathLength = geomStepLength;
|
|
|
|
// t = z for very small step
|
|
if(geomStepLength < tlimitminfix2) {
|
|
tPathLength = geomStepLength;
|
|
|
|
// recalculation
|
|
} else {
|
|
|
|
G4double tlength = geomStepLength;
|
|
if((geomStepLength > lambda0*tausmall) && !insideskin) {
|
|
|
|
if(par1 < 0.) {
|
|
tlength = -lambda0*G4Log(1.-geomStepLength/lambda0) ;
|
|
} else {
|
|
const G4double par4 = par1*par3;
|
|
if(par4*geomStepLength < 1.) {
|
|
tlength = (1.-G4Exp(G4Log(1.-par4*geomStepLength)/par3))/par1;
|
|
} else {
|
|
tlength = currentRange;
|
|
}
|
|
}
|
|
|
|
if(tlength < geomStepLength) { tlength = geomStepLength; }
|
|
else if(tlength > tPathLength) { tlength = tPathLength; }
|
|
}
|
|
tPathLength = tlength;
|
|
}
|
|
//G4cout << "Urban::ComputeTrueLength: tPathLength= " << tPathLength
|
|
// << " step= " << geomStepLength << " &&& " << G4endl;
|
|
|
|
return tPathLength;
|
|
}
|
|
|
|
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
|
|
|
|
G4ThreeVector&
|
|
G4UrbanMscModel::SampleScattering(const G4ThreeVector& oldDirection,
|
|
G4double /*safety*/)
|
|
{
|
|
fDisplacement.set(0.0,0.0,0.0);
|
|
G4double kinEnergy = currentKinEnergy;
|
|
if (tPathLength > currentRange*dtrl) {
|
|
kinEnergy = GetEnergy(particle,currentRange-tPathLength,couple);
|
|
} else if(tPathLength > currentRange*0.01) {
|
|
kinEnergy -= tPathLength*GetDEDX(particle,currentKinEnergy,couple,
|
|
currentLogKinEnergy);
|
|
}
|
|
|
|
if((tPathLength <= tlimitminfix) || (tPathLength < tausmall*lambda0) ||
|
|
(kinEnergy <= CLHEP::eV)) { return fDisplacement; }
|
|
|
|
G4double cth = SampleCosineTheta(tPathLength,kinEnergy);
|
|
|
|
// protection against 'bad' cth values
|
|
if(std::abs(cth) >= 1.0) { return fDisplacement; }
|
|
|
|
G4double sth = std::sqrt((1.0 - cth)*(1.0 + cth));
|
|
G4double phi = CLHEP::twopi*rndmEngineMod->flat();
|
|
G4ThreeVector newDirection(sth*std::cos(phi),sth*std::sin(phi),cth);
|
|
newDirection.rotateUz(oldDirection);
|
|
|
|
fParticleChange->ProposeMomentumDirection(newDirection);
|
|
/*
|
|
G4cout << "G4UrbanMscModel::SampleSecondaries: e(MeV)= " << kineticEnergy
|
|
<< " sinTheta= " << sth << " safety(mm)= " << safety
|
|
<< " trueStep(mm)= " << tPathLength
|
|
<< " geomStep(mm)= " << zPathLength
|
|
<< G4endl;
|
|
*/
|
|
|
|
if (latDisplasment && currentTau >= tausmall) {
|
|
if(dispAlg96) { SampleDisplacement(sth, phi); }
|
|
else { SampleDisplacementNew(cth, phi); }
|
|
fDisplacement.rotateUz(oldDirection);
|
|
}
|
|
return fDisplacement;
|
|
}
|
|
|
|
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
|
|
|
|
G4double G4UrbanMscModel::SampleCosineTheta(G4double trueStepLength,
|
|
G4double kinEnergy)
|
|
{
|
|
G4double cth = 1.0;
|
|
G4double tau = trueStepLength/lambda0;
|
|
|
|
// mean tau value
|
|
if(currentKinEnergy != kinEnergy) {
|
|
G4double lambda1 = GetTransportMeanFreePath(particle, kinEnergy);
|
|
if(std::abs(lambda1 - lambda0) > lambda0*0.01 && lambda1 > 0.) {
|
|
tau = trueStepLength*G4Log(lambda0/lambda1)/(lambda0-lambda1);
|
|
}
|
|
}
|
|
|
|
currentTau = tau;
|
|
lambdaeff = trueStepLength/currentTau;
|
|
currentRadLength = couple->GetMaterial()->GetRadlen();
|
|
|
|
if (tau >= taubig) { cth = -1.+2.*rndmEngineMod->flat(); }
|
|
else if (tau >= tausmall) {
|
|
static const G4double numlim = 0.01;
|
|
static const G4double onethird = 1./3.;
|
|
if(tau < numlim) {
|
|
xmeanth = 1.0 - tau*(1.0 - 0.5*tau);
|
|
x2meanth= 1.0 - tau*(5.0 - 6.25*tau)*onethird;
|
|
} else {
|
|
xmeanth = G4Exp(-tau);
|
|
x2meanth = (1.+2.*G4Exp(-2.5*tau))*onethird;
|
|
}
|
|
|
|
// too large step of low-energy particle
|
|
G4double relloss = 1. - kinEnergy/currentKinEnergy;
|
|
static const G4double rellossmax= 0.50;
|
|
if(relloss > rellossmax) {
|
|
return SimpleScattering();
|
|
}
|
|
// is step extreme small ?
|
|
G4bool extremesmallstep = false;
|
|
G4double tsmall = std::min(tlimitmin,lambdalimit);
|
|
G4double theta0;
|
|
if(trueStepLength > tsmall) {
|
|
theta0 = ComputeTheta0(trueStepLength,kinEnergy);
|
|
} else {
|
|
theta0 = std::sqrt(trueStepLength/tsmall)
|
|
*ComputeTheta0(tsmall,kinEnergy);
|
|
extremesmallstep = true;
|
|
}
|
|
|
|
static const G4double onesixth = 1./6.;
|
|
static const G4double theta0max = CLHEP::pi*onesixth;
|
|
//G4cout << "Theta0= " << theta0 << " theta0max= " << theta0max
|
|
// << " sqrt(tausmall)= " << sqrt(tausmall) << G4endl;
|
|
|
|
// protection for very small angles
|
|
G4double theta2 = theta0*theta0;
|
|
|
|
if(theta2 < tausmall) { return cth; }
|
|
|
|
if(theta0 > theta0max) { return SimpleScattering(); }
|
|
|
|
G4double x = theta2*(1.0 - theta2/12.);
|
|
if(theta2 > numlim) {
|
|
G4double sth = 2*std::sin(0.5*theta0);
|
|
x = sth*sth;
|
|
}
|
|
|
|
// parameter for tail
|
|
G4double ltau = G4Log(tau);
|
|
G4double u = !extremesmallstep ? G4Exp(ltau*onesixth)
|
|
: G4Exp(G4Log(tsmall/lambda0)*onesixth);
|
|
|
|
G4double xx = G4Log(lambdaeff/currentRadLength);
|
|
G4double xsi = msc[idx]->coeffc1 +
|
|
u*(msc[idx]->coeffc2+msc[idx]->coeffc3*u)+msc[idx]->coeffc4*xx;
|
|
|
|
// tail should not be too big
|
|
xsi = std::max(xsi, 1.9);
|
|
/*
|
|
if(KineticEnergy > 20*MeV && xsi < 1.6) {
|
|
G4cout << "G4UrbanMscModel::SampleCosineTheta: E(GeV)= "
|
|
<< KineticEnergy/GeV
|
|
<< " !!** c= " << xsi
|
|
<< " **!! length(mm)= " << trueStepLength << " Zeff= " << Zeff
|
|
<< " " << couple->GetMaterial()->GetName()
|
|
<< " tau= " << tau << G4endl;
|
|
}
|
|
*/
|
|
|
|
G4double c = xsi;
|
|
|
|
if(std::abs(c-3.) < 0.001) { c = 3.001; }
|
|
else if(std::abs(c-2.) < 0.001) { c = 2.001; }
|
|
|
|
G4double c1 = c-1.;
|
|
G4double ea = G4Exp(-xsi);
|
|
G4double eaa = 1.-ea ;
|
|
G4double xmean1 = 1.-(1.-(1.+xsi)*ea)*x/eaa;
|
|
G4double x0 = 1. - xsi*x;
|
|
|
|
// G4cout << " xmean1= " << xmean1 << " xmeanth= " << xmeanth << G4endl;
|
|
|
|
if(xmean1 <= 0.999*xmeanth) { return SimpleScattering(); }
|
|
|
|
//from continuity of derivatives
|
|
G4double b = 1.+(c-xsi)*x;
|
|
|
|
G4double b1 = b+1.;
|
|
G4double bx = c*x;
|
|
|
|
G4double eb1 = G4Exp(G4Log(b1)*c1);
|
|
G4double ebx = G4Exp(G4Log(bx)*c1);
|
|
G4double d = ebx/eb1;
|
|
|
|
G4double xmean2 = (x0 + d - (bx - b1*d)/(c-2.))/(1. - d);
|
|
|
|
G4double f1x0 = ea/eaa;
|
|
G4double f2x0 = c1/(c*(1. - d));
|
|
G4double prob = f2x0/(f1x0+f2x0);
|
|
|
|
G4double qprob = xmeanth/(prob*xmean1+(1.-prob)*xmean2);
|
|
|
|
// sampling of costheta
|
|
//G4cout << "c= " << c << " qprob= " << qprob << " eb1= " << eb1
|
|
// << " c1= " << c1 << " b1= " << b1 << " bx= " << bx << " eb1= " << eb1
|
|
// << G4endl;
|
|
rndmEngineMod->flatArray(2, rndmarray);
|
|
if(rndmarray[0] < qprob)
|
|
{
|
|
G4double var = 0;
|
|
if(rndmarray[1] < prob) {
|
|
cth = 1.+G4Log(ea+rndmEngineMod->flat()*eaa)*x;
|
|
} else {
|
|
var = (1.0 - d)*rndmEngineMod->flat();
|
|
if(var < numlim*d) {
|
|
var /= (d*c1);
|
|
cth = -1.0 + var*(1.0 - 0.5*var*c)*(2. + (c - xsi)*x);
|
|
} else {
|
|
cth = 1. + x*(c - xsi - c*G4Exp(-G4Log(var + d)/c1));
|
|
}
|
|
}
|
|
} else {
|
|
cth = -1.+2.*rndmarray[1];
|
|
}
|
|
}
|
|
return cth;
|
|
}
|
|
|
|
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
|
|
|
|
G4double G4UrbanMscModel::ComputeTheta0(G4double trueStepLength,
|
|
G4double kinEnergy)
|
|
{
|
|
// for all particles take the width of the central part
|
|
// from a parametrization similar to the Highland formula
|
|
// ( Highland formula: Particle Physics Booklet, July 2002, eq. 26.10)
|
|
G4double invbetacp = (kinEnergy+mass)/(kinEnergy*(kinEnergy+2.*mass));
|
|
if(currentKinEnergy != kinEnergy) {
|
|
invbetacp = std::sqrt(invbetacp*(currentKinEnergy+mass)/
|
|
(currentKinEnergy*(currentKinEnergy+2.*mass)));
|
|
}
|
|
G4double y = trueStepLength/currentRadLength;
|
|
|
|
if(particle == positron)
|
|
{
|
|
static const G4double xl= 0.6;
|
|
static const G4double xh= 0.9;
|
|
static const G4double e = 113.0;
|
|
G4double corr;
|
|
|
|
G4double tau = std::sqrt(currentKinEnergy*kinEnergy)/mass;
|
|
G4double x = std::sqrt(tau*(tau+2.)/((tau+1.)*(tau+1.)));
|
|
G4double a = msc[idx]->posa;
|
|
G4double b = msc[idx]->posb;
|
|
G4double c = msc[idx]->posc;
|
|
G4double d = msc[idx]->posd;
|
|
if(x < xl) {
|
|
corr = a*(1.-G4Exp(-b*x));
|
|
} else if(x > xh) {
|
|
corr = c+d*G4Exp(e*(x-1.));
|
|
} else {
|
|
G4double yl = a*(1.-G4Exp(-b*xl));
|
|
G4double yh = c+d*G4Exp(e*(xh-1.));
|
|
G4double y0 = (yh-yl)/(xh-xl);
|
|
G4double y1 = yl-y0*xl;
|
|
corr = y0*x+y1;
|
|
}
|
|
//==================================================================
|
|
y *= corr*msc[idx]->pose;
|
|
}
|
|
|
|
static const G4double c_highland = 13.6*CLHEP::MeV;
|
|
G4double theta0 = c_highland*std::abs(charge)*std::sqrt(y)*invbetacp;
|
|
|
|
// correction factor from e- scattering data
|
|
theta0 *= (msc[idx]->coeffth1+msc[idx]->coeffth2*G4Log(y));
|
|
return theta0;
|
|
}
|
|
|
|
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
|
|
|
|
void G4UrbanMscModel::SampleDisplacement(G4double, G4double phi)
|
|
{
|
|
// simple and fast sampling
|
|
// based on single scattering results
|
|
// u = r/rmax : mean value
|
|
|
|
G4double rmax = std::sqrt((tPathLength-zPathLength)*(tPathLength+zPathLength));
|
|
if(rmax > 0.)
|
|
{
|
|
G4double r = 0.73*rmax;
|
|
|
|
// simple distribution for v=Phi-phi=psi ~exp(-beta*v)
|
|
// beta determined from the requirement that distribution should give
|
|
// the same mean value than that obtained from the ss simulation
|
|
|
|
static const G4double cbeta = 2.160;
|
|
static const G4double cbeta1 = 1. - G4Exp(-cbeta*CLHEP::pi);
|
|
rndmEngineMod->flatArray(2, rndmarray);
|
|
G4double psi = -G4Log(1. - rndmarray[0]*cbeta1)/cbeta;
|
|
G4double Phi = (rndmarray[1] < 0.5) ? phi+psi : phi-psi;
|
|
fDisplacement.set(r*std::cos(Phi),r*std::sin(Phi),0.0);
|
|
}
|
|
}
|
|
|
|
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
|
|
|
|
void G4UrbanMscModel::SampleDisplacementNew(G4double, G4double phi)
|
|
{
|
|
// best sampling based on single scattering results
|
|
G4double rmax =
|
|
std::sqrt((tPathLength-zPathLength)*(tPathLength+zPathLength));
|
|
G4double r(0.0);
|
|
G4double u(0.0);
|
|
static const G4double reps = 5.e-3;
|
|
|
|
if(rmax > 0.)
|
|
{
|
|
static const G4double umax = 0.855;
|
|
static const G4double wlow = 0.750;
|
|
|
|
static const G4double ralpha = 6.83e+0;
|
|
static const G4double ra1 =-4.16179e+1;
|
|
static const G4double ra2 = 1.12548e+2;
|
|
static const G4double ra3 =-8.66665e+1;
|
|
static const G4double ralpha1 = 0.751*ralpha;
|
|
static const G4double ralpha2 =ralpha-ralpha1;
|
|
static const G4double rwa1 = G4Exp(ralpha1*reps);
|
|
static const G4double rwa2 = G4Exp(ralpha1*umax)-rwa1;
|
|
static const G4double rejamax = 1.16456;
|
|
|
|
static const G4double rbeta = 2.18e+1;
|
|
static const G4double rb0 = 4.81382e+2;
|
|
static const G4double rb1 =-1.12842e+4;
|
|
static const G4double rb2 = 4.57745e+4;
|
|
static const G4double rbeta1 = 0.732*rbeta;
|
|
static const G4double rbeta2 = rbeta-rbeta1;
|
|
static const G4double rwb1 = G4Exp(-rbeta1*umax);
|
|
static const G4double rwb2 = rwb1-G4Exp(-rbeta1*(1.-reps));
|
|
static const G4double rejbmax = 1.62651;
|
|
|
|
G4int count = 0;
|
|
G4double uc,rej;
|
|
|
|
if(rndmEngineMod->flat() < wlow)
|
|
{
|
|
do {
|
|
rndmEngineMod->flatArray(2, rndmarray);
|
|
u = G4Log(rwa1+rwa2*rndmarray[0])/ralpha1;
|
|
uc = umax-u;
|
|
rej = G4Exp(-ralpha2*uc)*
|
|
(1.+ralpha*uc+ra1*uc*uc+ra2*uc*uc*uc+ra3*uc*uc*uc*uc);
|
|
} while (rejamax*rndmarray[1] > rej && ++count < 1000);
|
|
}
|
|
else
|
|
{
|
|
do {
|
|
rndmEngineMod->flatArray(2, rndmarray);
|
|
u = -G4Log(rwb1-rwb2*rndmarray[0])/rbeta1;
|
|
uc = u-umax;
|
|
rej = G4Exp(-rbeta2*uc)*
|
|
(1.+rbeta*uc+rb0*uc*uc+rb1*uc*uc*uc+rb2*uc*uc*uc*uc);
|
|
} while (rejbmax*rndmarray[1] > rej && ++count < 1000);
|
|
}
|
|
r = rmax*u;
|
|
}
|
|
|
|
if(r > 0.)
|
|
{
|
|
// sample Phi using lateral correlation
|
|
// and r/rmax - (Phi-phi) correlation
|
|
// v = Phi-phi = acos(latcorr/(r*sth))
|
|
// from SS simulation f(v)*g(v)
|
|
// f(v) ~ exp(-a1*v) normalized distribution
|
|
// g(v) rejection function (0 < g(v) <= 1)
|
|
G4double v, rej;
|
|
|
|
static const G4double peps = 1.e-4;
|
|
static const G4double palpha[10] = {2.300e+0,2.490e+0,2.610e+0,2.820e+0,2.710e+0,
|
|
2.750e+0,2.910e+0,3.400e+0,4.150e+0,5.400e+0};
|
|
static const G4double palpha1[10]= {4.600e-2,1.245e-1,2.610e-1,2.820e-1,2.710e-1,
|
|
6.875e-1,1.019e+0,1.360e+0,1.660e+0,2.430e+0};
|
|
static const G4double pejmax[10] = {3.513,1.968,1.479,1.239,1.116,
|
|
1.081,1.064,1.073,1.103,1.158};
|
|
|
|
static const G4double pa1[10] = { 3.218e+0, 2.412e+0, 2.715e+0, 2.787e+0, 2.541e+0,
|
|
2.508e+0, 2.600e+0, 3.231e+0, 4.588e+0, 6.584e+0};
|
|
static const G4double pa2[10] = {-5.528e-1, 2.523e+0, 1.738e+0, 2.082e+0, 1.423e+0,
|
|
4.682e-1,-6.883e-1,-2.147e+0,-5.127e+0,-1.054e+1};
|
|
static const G4double pa3[10] = { 3.618e+0, 2.032e+0, 2.341e+0, 2.172e+0, 7.205e-1,
|
|
4.655e-1, 6.318e-1, 1.255e+0, 2.425e+0, 4.938e+0};
|
|
static const G4double pa4[10] = { 2.437e+0, 9.450e-1, 4.349e-1, 2.221e-1, 1.130e-1,
|
|
5.405e-2, 2.245e-2, 7.370e-3, 1.456e-3, 1.508e-4};
|
|
static const G4double pw1[10] = {G4Exp(-palpha1[0]*peps),G4Exp(-palpha1[1]*peps),
|
|
G4Exp(-palpha1[2]*peps),G4Exp(-palpha1[3]*peps),
|
|
G4Exp(-palpha1[4]*peps),G4Exp(-palpha1[5]*peps),
|
|
G4Exp(-palpha1[6]*peps),G4Exp(-palpha1[7]*peps),
|
|
G4Exp(-palpha1[8]*peps),G4Exp(-palpha1[9]*peps)};
|
|
static const G4double pw2[10] = {pw1[0]-G4Exp(-palpha1[0]*(CLHEP::pi-peps)),
|
|
pw1[1]-G4Exp(-palpha1[1]*(CLHEP::pi-peps)),
|
|
pw1[2]-G4Exp(-palpha1[2]*(CLHEP::pi-peps)),
|
|
pw1[3]-G4Exp(-palpha1[3]*(CLHEP::pi-peps)),
|
|
pw1[4]-G4Exp(-palpha1[4]*(CLHEP::pi-peps)),
|
|
pw1[5]-G4Exp(-palpha1[5]*(CLHEP::pi-peps)),
|
|
pw1[6]-G4Exp(-palpha1[6]*(CLHEP::pi-peps)),
|
|
pw1[7]-G4Exp(-palpha1[7]*(CLHEP::pi-peps)),
|
|
pw1[8]-G4Exp(-palpha1[8]*(CLHEP::pi-peps)),
|
|
pw1[9]-G4Exp(-palpha1[9]*(CLHEP::pi-peps))};
|
|
|
|
G4int iphi = (G4int)(u*10.);
|
|
if(iphi < 0) { iphi = 0; }
|
|
else if(iphi > 9) { iphi = 9; }
|
|
G4int count = 0;
|
|
|
|
do {
|
|
rndmEngineMod->flatArray(2, rndmarray);
|
|
v = -G4Log(pw1[iphi]-pw2[iphi]*rndmarray[0])/palpha1[iphi];
|
|
rej = (G4Exp(-palpha[iphi]*v)*
|
|
(1+pa1[iphi]*v+pa2[iphi]*v*v+pa3[iphi]*v*v*v)+pa4[iphi])/
|
|
G4Exp(-pw1[iphi]*v);
|
|
}
|
|
// Loop checking, 5-March-2018, Vladimir Ivanchenko
|
|
while (pejmax[iphi]*rndmarray[1] > rej && ++count < 1000);
|
|
|
|
G4double Phi = (rndmEngineMod->flat() < 0.5) ? phi+v : phi-v;
|
|
fDisplacement.set(r*std::cos(Phi),r*std::sin(Phi),0.0);
|
|
}
|
|
}
|
|
|
|
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
|
|
|
|
void G4UrbanMscModel::InitialiseModelCache()
|
|
{
|
|
// it is assumed, that for the second run only addition
|
|
// of a new G4MaterialCutsCouple is possible
|
|
auto theCoupleTable = G4ProductionCutsTable::GetProductionCutsTable();
|
|
size_t numOfCouples = theCoupleTable->GetTableSize();
|
|
if(numOfCouples != msc.size()) { msc.resize(numOfCouples, nullptr); }
|
|
|
|
for(size_t j=0; j<numOfCouples; ++j) {
|
|
auto aCouple = theCoupleTable->GetMaterialCutsCouple(j);
|
|
|
|
// cut may be changed before runs
|
|
G4double cut = aCouple->GetProductionCuts()->GetProductionCut(1);
|
|
if(nullptr != msc[j]) {
|
|
msc[j]->ecut = cut;
|
|
continue;
|
|
}
|
|
// new couple
|
|
msc[j] = new mscData();
|
|
msc[j]->ecut = cut;
|
|
G4double Zeff = aCouple->GetMaterial()->GetIonisation()->GetZeffective();
|
|
msc[j]->sqrtZ = std::sqrt(Zeff);
|
|
G4double lnZ = G4Log(Zeff);
|
|
// correction in theta0 formula
|
|
G4double w = G4Exp(lnZ/6.);
|
|
G4double facz = 0.990395+w*(-0.168386+w*0.093286);
|
|
msc[j]->coeffth1 = facz*(1. - 8.7780e-2/Zeff);
|
|
msc[j]->coeffth2 = facz*(4.0780e-2 + 1.7315e-4*Zeff);
|
|
|
|
// tail parameters
|
|
G4double Z13 = w*w;
|
|
msc[j]->coeffc1 = 2.3785 - Z13*(4.1981e-1 - Z13*6.3100e-2);
|
|
msc[j]->coeffc2 = 4.7526e-1 + Z13*(1.7694 - Z13*3.3885e-1);
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msc[j]->coeffc3 = 2.3683e-1 - Z13*(1.8111 - Z13*3.2774e-1);
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msc[j]->coeffc4 = 1.7888e-2 + Z13*(1.9659e-2 - Z13*2.6664e-3);
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msc[j]->Z23 = Z13*Z13;
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msc[j]->stepmina = 27.725/(1.+0.203*Zeff);
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msc[j]->stepminb = 6.152/(1.+0.111*Zeff);
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// 21.07.2020
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msc[j]->doverra = 9.6280e-1 - 8.4848e-2*msc[j]->sqrtZ + 4.3769e-3*Zeff;
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// 06.10.2020
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// msc[j]->doverra = 7.7024e-1 - 6.7878e-2*msc[j]->sqrtZ + 3.5015e-3*Zeff;
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msc[j]->doverrb = 1.15 - 9.76e-4*Zeff;
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// corrections for e+
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msc[j]->posa = 0.994-4.08e-3*Zeff;
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msc[j]->posb = 7.16+(52.6+365./Zeff)/Zeff;
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msc[j]->posc = 1.000-4.47e-3*Zeff;
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msc[j]->posd = 1.21e-3*Zeff;
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msc[j]->pose = 1.+Zeff*(1.84035e-4*Zeff-1.86427e-2)+0.41125;
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}
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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