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Please see the license in the file LICENSE and URL above * 16 // * for the full disclaimer and the limitatio 16 // * for the full disclaimer and the limitation of liability. * 17 // * 17 // * * 18 // * This code implementation is the result 18 // * This code implementation is the result of the scientific and * 19 // * technical work of the GEANT4 collaboratio 19 // * technical work of the GEANT4 collaboration. * 20 // * By using, copying, modifying or distri 20 // * By using, copying, modifying or distributing the software (or * 21 // * any work based on the software) you ag 21 // * any work based on the software) you agree to acknowledge its * 22 // * use in resulting scientific publicati 22 // * use in resulting scientific publications, and indicate your * 23 // * acceptance of all terms of the Geant4 Sof 23 // * acceptance of all terms of the Geant4 Software license. * 24 // ******************************************* 24 // ******************************************************************** 25 // 25 // >> 26 // $Id: G4GoudsmitSaundersonMscModel.cc 106953 2017-10-31 08:30:13Z gcosmo $ 26 // 27 // 27 // ------------------------------------------- 28 // ---------------------------------------------------------------------------- 28 // 29 // 29 // GEANT4 Class implementation file 30 // GEANT4 Class implementation file 30 // 31 // 31 // File name: G4GoudsmitSaundersonMscModel 32 // File name: G4GoudsmitSaundersonMscModel 32 // 33 // 33 // Author: Mihaly Novak / (Omrane Kadri 34 // Author: Mihaly Novak / (Omrane Kadri) 34 // 35 // 35 // Creation date: 20.02.2009 36 // Creation date: 20.02.2009 36 // 37 // 37 // Modifications: 38 // Modifications: 38 // 04.03.2009 V.Ivanchenko cleanup and format 39 // 04.03.2009 V.Ivanchenko cleanup and format according to Geant4 EM style 39 // 12.05.2010 O.Kadri: adding Qn1 and Qn12 as 40 // 12.05.2010 O.Kadri: adding Qn1 and Qn12 as private doubles 40 // 18.05.2015 M. Novak provide PRELIMINARY ver 41 // 18.05.2015 M. Novak provide PRELIMINARY verison of the revised class 41 // This class has been revised and 42 // This class has been revised and updated, new methods added. 42 // A new version of Kawrakow-Bielaj 43 // A new version of Kawrakow-Bielajew Goudsmit-Saunderson MSC model 43 // based on the screened Rutherford 44 // based on the screened Rutherford DCS for elastic scattering of 44 // electrons/positrons has been int 45 // electrons/positrons has been introduced[1,2]. The corresponding MSC 45 // angular distributions over a 2D 46 // angular distributions over a 2D parameter grid have been recomputed 46 // and the CDFs are now stored in a 47 // and the CDFs are now stored in a variable transformed (smooth) form[2,3] 47 // together with the corresponding 48 // together with the corresponding rational interpolation parameters. 48 // These angular distributions are 49 // These angular distributions are handled by the new 49 // G4GoudsmitSaundersonTable class 50 // G4GoudsmitSaundersonTable class that is responsible to sample if 50 // it was no, single, few or multip 51 // it was no, single, few or multiple scattering case and delivers the 51 // angular deflection (i.e. cos(the 52 // angular deflection (i.e. cos(theta) and sin(theta)). 52 // Two screening options are provid 53 // Two screening options are provided: 53 // - if fIsUsePWATotalXsecData=TRU 54 // - if fIsUsePWATotalXsecData=TRUE i.e. SetOptionPWAScreening(TRUE) 54 // was called before initialisat 55 // was called before initialisation: screening parameter value A is 55 // determined such that the firs 56 // determined such that the first transport coefficient G1(A) 56 // computed according to the scr 57 // computed according to the screened Rutherford DCS for elastic 57 // scattering will reproduce the 58 // scattering will reproduce the one computed from the PWA elastic 58 // and first transport mean free 59 // and first transport mean free paths[4]. 59 // - if fIsUsePWATotalXsecData=FAL 60 // - if fIsUsePWATotalXsecData=FALSE i.e. default value or 60 // SetOptionPWAScreening(FALSE) 61 // SetOptionPWAScreening(FALSE) was called before initialisation: 61 // screening parameter value A i 62 // screening parameter value A is computed according to Moliere's 62 // formula (by using material de 63 // formula (by using material dependent parameters \chi_cc2 and b_c 63 // precomputed for each material 64 // precomputed for each material used at initialization in 64 // G4GoudsmitSaundersonTable) [3 65 // G4GoudsmitSaundersonTable) [3] 65 // Elastic and first trasport mean 66 // Elastic and first trasport mean free paths are used consistently. 66 // The new version is self-consiste 67 // The new version is self-consistent, several times faster, more 67 // robust and accurate compared to 68 // robust and accurate compared to the earlier version. 68 // Spin effects as well as a more a 69 // Spin effects as well as a more accurate energy loss correction and 69 // computations of Lewis moments wi 70 // computations of Lewis moments will be implemented later on. 70 // 02.09.2015 M. Novak: first version of new s 71 // 02.09.2015 M. Novak: first version of new step limit is provided. 71 // fUseSafetyPlus corresponds to Ur 72 // fUseSafetyPlus corresponds to Urban fUseSafety (default) 72 // fUseDistanceToBoundary correspon 73 // fUseDistanceToBoundary corresponds to Urban fUseDistanceToBoundary 73 // fUseSafety corresponds to EGSnr 74 // fUseSafety corresponds to EGSnrc error-free stepping algorithm 74 // Range factor can be significantl 75 // Range factor can be significantly higher at each case than in Urban. 75 // 23.08.2017 M. Novak: added corrections to a 76 // 23.08.2017 M. Novak: added corrections to account spin effects (Mott-correction). 76 // It can be activated by setting t 77 // It can be activated by setting the fIsMottCorrection flag to be true 77 // before initialization using the 78 // before initialization using the SetOptionMottCorrection() public method. 78 // The fMottCorrection member is re 79 // The fMottCorrection member is responsible to handle pre-computed Mott 79 // correction (rejection) functions 80 // correction (rejection) functions obtained by numerically computing 80 // Goudsmit-Saunderson agnular dist 81 // Goudsmit-Saunderson agnular distributions based on a DCS accounting spin 81 // effects and screening correction 82 // effects and screening corrections. The DCS used to compute the accurate 82 // GS angular distributions is: DCS 83 // GS angular distributions is: DCS_{cor} = DCS_{SR}x[ DCS_{R}/DCS_{Mott}] where : 83 // # DCS_{SR} is the relativisti 84 // # DCS_{SR} is the relativistic Screened-Rutherford DCS (first Born approximate 84 // solution of the Klein-Gordo 85 // solution of the Klein-Gordon i.e. relativistic Schrodinger equation => 85 // scattering of spinless e- o 86 // scattering of spinless e- on exponentially screened Coulomb potential) 86 // note: the default (without 87 // note: the default (without using Mott-correction) GS angular distributions 87 // are based on this DCS_{SR} 88 // are based on this DCS_{SR} with Moliere's screening parameter! 88 // # DCS_{R} is the Rutherford D 89 // # DCS_{R} is the Rutherford DCS which is the same as above but without 89 // screening 90 // screening 90 // # DCS_{Mott} is the Mott DCS 91 // # DCS_{Mott} is the Mott DCS i.e. solution of the Dirac equation with a bare 91 // Coulomb potential i.e. scat 92 // Coulomb potential i.e. scattering of particles with spin (e- or e+) on a 92 // point-like unscreened Coulo 93 // point-like unscreened Coulomb potential 93 // # moreover, the screening par 94 // # moreover, the screening parameter of the DCS_{cor} was determined such that 94 // the DCS_{cor} with this cor 95 // the DCS_{cor} with this corrected screening parameter reproduce the first 95 // transport cross sections ob 96 // transport cross sections obtained from the corresponding most accurate DCS 96 // (i.e. from elsepa [4]) 97 // (i.e. from elsepa [4]) 97 // Unlike the default GS, the Mott- 98 // Unlike the default GS, the Mott-corrected angular distributions are particle type 98 // (different for e- and e+ <= the 99 // (different for e- and e+ <= the DCS_{Mott} and the screening correction) and target 99 // (Z and material) dependent. 100 // (Z and material) dependent. 100 // 27.10.2017 M. Novak: 101 // 27.10.2017 M. Novak: 101 // - Mott-correction flag is set no 102 // - Mott-correction flag is set now through the G4EmParameters 102 // - new form of PWA correction to 103 // - new form of PWA correction to integrated quantities and screening (default) 103 // - changed step limit flag conven 104 // - changed step limit flag conventions: 104 // # fUseSafety corresponds to U 105 // # fUseSafety corresponds to Urban's fUseSafety 105 // # fUseDistanceToBoundary corr 106 // # fUseDistanceToBoundary corresponds to Urban's fUseDistanceToBoundary 106 // # fUseSafetyPlus corresponds 107 // # fUseSafetyPlus corresponds to the error-free stepping algorithm 107 // 02.02.2018 M. Novak: implemented CrossSecti << 108 // 108 // 109 // Class description: 109 // Class description: 110 // Kawrakow-Bielajew Goudsmit-Saunderson MSC 110 // Kawrakow-Bielajew Goudsmit-Saunderson MSC model based on the screened Rutherford DCS 111 // for elastic scattering of e-/e+. Option, 111 // for elastic scattering of e-/e+. Option, to include (Mott) correction (see above), is 112 // also available now (SetOptionMottCorrecti 112 // also available now (SetOptionMottCorrection(true)). An EGSnrc like error-free stepping 113 // algorithm (UseSafety) is available beyond 113 // algorithm (UseSafety) is available beyond the usual Geant4 step limitation algorithms 114 // and true to geomerty and geometry to true 114 // and true to geomerty and geometry to true step length computations that were adopted 115 // from the Urban model[5]. The most accurat 115 // from the Urban model[5]. The most accurate setting: error-free stepping i.e. the 116 // UseSafetyPlus MSC step limit with Mott-co 116 // UseSafetyPlus MSC step limit with Mott-correction (SetOptionMottCorrection(true)). Both 117 // are expected to be set through the G4EmPa 117 // are expected to be set through the G4EmParameters singleton before initialisation: 118 // # G4EmParameters::Instance()->SetMscStep 118 // # G4EmParameters::Instance()->SetMscStepLimitType(fUseSafetyPlus); 119 // # G4EmParameters::Instance()->SetUseMott 119 // # G4EmParameters::Instance()->SetUseMottCorrection(true); 120 // 120 // 121 // 121 // 122 // References: 122 // References: 123 // [1] A.F.Bielajew, NIMB 111 (1996) 195-208 123 // [1] A.F.Bielajew, NIMB 111 (1996) 195-208 124 // [2] I.Kawrakow, A.F.Bielajew, NIMB 134(19 124 // [2] I.Kawrakow, A.F.Bielajew, NIMB 134(1998) 325-336 125 // [3] I.Kawrakow, E.Mainegra-Hing, D.W.O.Ro 125 // [3] I.Kawrakow, E.Mainegra-Hing, D.W.O.Rogers, F.Tessier,B.R.B.Walters, NRCC 126 // Report PIRS-701 (2013) 126 // Report PIRS-701 (2013) 127 // [4] F.Salvat, A.Jablonski, C.J. Powell, C 127 // [4] F.Salvat, A.Jablonski, C.J. Powell, CPC 165(2005) 157-190 128 // [5] L.Urban, Preprint CERN-OPEN-2006-077 128 // [5] L.Urban, Preprint CERN-OPEN-2006-077 (2006) 129 // 129 // 130 // ------------------------------------------- 130 // ----------------------------------------------------------------------------- 131 131 132 132 133 #include "G4GoudsmitSaundersonMscModel.hh" 133 #include "G4GoudsmitSaundersonMscModel.hh" 134 134 135 #include "G4GoudsmitSaundersonTable.hh" 135 #include "G4GoudsmitSaundersonTable.hh" 136 #include "G4GSPWACorrections.hh" 136 #include "G4GSPWACorrections.hh" 137 137 138 #include "G4PhysicalConstants.hh" 138 #include "G4PhysicalConstants.hh" 139 #include "G4SystemOfUnits.hh" 139 #include "G4SystemOfUnits.hh" 140 140 141 #include "G4ParticleChangeForMSC.hh" 141 #include "G4ParticleChangeForMSC.hh" 142 #include "G4DynamicParticle.hh" 142 #include "G4DynamicParticle.hh" 143 #include "G4Electron.hh" 143 #include "G4Electron.hh" 144 #include "G4Positron.hh" 144 #include "G4Positron.hh" 145 145 146 #include "G4LossTableManager.hh" 146 #include "G4LossTableManager.hh" 147 #include "G4EmParameters.hh" 147 #include "G4EmParameters.hh" 148 #include "G4Track.hh" 148 #include "G4Track.hh" 149 #include "G4PhysicsTable.hh" 149 #include "G4PhysicsTable.hh" 150 #include "Randomize.hh" 150 #include "Randomize.hh" 151 #include "G4Log.hh" 151 #include "G4Log.hh" 152 #include "G4Exp.hh" 152 #include "G4Exp.hh" 153 #include "G4Pow.hh" 153 #include "G4Pow.hh" 154 #include <fstream> 154 #include <fstream> 155 155 156 156 157 // set accurate energy loss and dispalcement s 157 // set accurate energy loss and dispalcement sampling to be always on now 158 G4bool G4GoudsmitSaundersonMscModel::gIsUseAcc 158 G4bool G4GoudsmitSaundersonMscModel::gIsUseAccurate = true; 159 // set the usual optimization to be always act 159 // set the usual optimization to be always active now 160 G4bool G4GoudsmitSaundersonMscModel::gIsOptimi 160 G4bool G4GoudsmitSaundersonMscModel::gIsOptimizationOn = true; 161 161 162 162 163 G4GoudsmitSaundersonMscModel::G4GoudsmitSaunde 163 G4GoudsmitSaundersonMscModel::G4GoudsmitSaundersonMscModel(const G4String& nam) 164 : G4VMscModel(nam) { 164 : G4VMscModel(nam) { 165 charge = 0; 165 charge = 0; 166 currentMaterialIndex = -1; 166 currentMaterialIndex = -1; 167 // 167 // >> 168 lambdalimit = 1.*mm; 168 fr = 0.1; 169 fr = 0.1; 169 rangeinit = 1.e+21; 170 rangeinit = 1.e+21; 170 geombig = 1.e+50*mm; 171 geombig = 1.e+50*mm; 171 geomlimit = geombig; 172 geomlimit = geombig; 172 tgeom = geombig; 173 tgeom = geombig; 173 tlimit = 1.e+10*mm; 174 tlimit = 1.e+10*mm; 174 presafety = 0.*mm; 175 presafety = 0.*mm; 175 // 176 // 176 particle = nullptr; << 177 particle = 0; 177 theManager = G4LossTableManager: 178 theManager = G4LossTableManager::Instance(); 178 firstStep = true; 179 firstStep = true; 179 currentKinEnergy = 0.0; 180 currentKinEnergy = 0.0; 180 currentRange = 0.0; 181 currentRange = 0.0; 181 // 182 // 182 tlimitminfix2 = 1.*nm; 183 tlimitminfix2 = 1.*nm; 183 tausmall = 1.e-16; 184 tausmall = 1.e-16; 184 mass = electron_mass_c2; 185 mass = electron_mass_c2; 185 taulim = 1.e-6; 186 taulim = 1.e-6; 186 // 187 // >> 188 facsafety = 0.6; >> 189 187 currentCouple = nullptr; 190 currentCouple = nullptr; 188 fParticleChange = nullptr; 191 fParticleChange = nullptr; 189 // 192 // 190 fZeff = 1.; 193 fZeff = 1.; 191 // 194 // 192 par1 = 0.; 195 par1 = 0.; 193 par2 = 0.; 196 par2 = 0.; 194 par3 = 0.; 197 par3 = 0.; 195 // 198 // 196 // Moliere screeing parameter will be used a 199 // Moliere screeing parameter will be used and (by default) corrections are 197 // appalied to the integrated quantities (sc 200 // appalied to the integrated quantities (screeing parameter, elastic mfp, first 198 // and second moments) derived from the corr 201 // and second moments) derived from the corresponding PWA quantities 199 // this PWA correction is ignored if Mott-co 202 // this PWA correction is ignored if Mott-correction is set to true because 200 // Mott-correction contains all these correc 203 // Mott-correction contains all these corrections as well 201 fIsUsePWACorrection = true; 204 fIsUsePWACorrection = true; 202 // 205 // 203 fIsUseMottCorrection = false; 206 fIsUseMottCorrection = false; 204 // 207 // 205 fLambda0 = 0.0; // elastic mea 208 fLambda0 = 0.0; // elastic mean free path 206 fLambda1 = 0.0; // first trans 209 fLambda1 = 0.0; // first transport mean free path 207 fScrA = 0.0; // screening p 210 fScrA = 0.0; // screening parameter 208 fG1 = 0.0; // first trans 211 fG1 = 0.0; // first transport coef. 209 // 212 // 210 fMCtoScrA = 1.0; 213 fMCtoScrA = 1.0; 211 fMCtoQ1 = 1.0; 214 fMCtoQ1 = 1.0; 212 fMCtoG2PerG1 = 1.0; 215 fMCtoG2PerG1 = 1.0; 213 // 216 // 214 fTheTrueStepLenght = 0.; 217 fTheTrueStepLenght = 0.; 215 fTheTransportDistance = 0.; 218 fTheTransportDistance = 0.; 216 fTheZPathLenght = 0.; 219 fTheZPathLenght = 0.; 217 // 220 // 218 fTheDisplacementVector.set(0.,0.,0.); 221 fTheDisplacementVector.set(0.,0.,0.); 219 fTheNewDirection.set(0.,0.,1.); 222 fTheNewDirection.set(0.,0.,1.); 220 // 223 // 221 fIsEverythingWasDone = false; 224 fIsEverythingWasDone = false; 222 fIsMultipleSacettring = false; 225 fIsMultipleSacettring = false; 223 fIsSingleScattering = false; 226 fIsSingleScattering = false; 224 fIsEndedUpOnBoundary = false; 227 fIsEndedUpOnBoundary = false; 225 fIsNoScatteringInMSC = false; 228 fIsNoScatteringInMSC = false; 226 fIsNoDisplace = false; 229 fIsNoDisplace = false; 227 fIsInsideSkin = false; 230 fIsInsideSkin = false; 228 fIsWasOnBoundary = false; 231 fIsWasOnBoundary = false; 229 fIsFirstRealStep = false; 232 fIsFirstRealStep = false; 230 rndmEngineMod = G4Random::getTheEng 233 rndmEngineMod = G4Random::getTheEngine(); 231 // 234 // 232 fGSTable = nullptr; 235 fGSTable = nullptr; 233 fPWACorrection = nullptr; 236 fPWACorrection = nullptr; 234 } 237 } 235 238 236 239 237 G4GoudsmitSaundersonMscModel::~G4GoudsmitSaund 240 G4GoudsmitSaundersonMscModel::~G4GoudsmitSaundersonMscModel() { 238 if (IsMaster()) { 241 if (IsMaster()) { 239 if (fGSTable) { 242 if (fGSTable) { 240 delete fGSTable; 243 delete fGSTable; 241 fGSTable = nullptr; 244 fGSTable = nullptr; 242 } 245 } 243 if (fPWACorrection) { 246 if (fPWACorrection) { 244 delete fPWACorrection; 247 delete fPWACorrection; 245 fPWACorrection = nullptr; 248 fPWACorrection = nullptr; 246 } 249 } 247 } 250 } 248 } 251 } 249 252 250 253 251 void G4GoudsmitSaundersonMscModel::Initialise( 254 void G4GoudsmitSaundersonMscModel::Initialise(const G4ParticleDefinition* p, const G4DataVector&) { 252 SetParticle(p); 255 SetParticle(p); 253 InitialiseParameters(p); << 256 fParticleChange = GetParticleChangeForMSC(p); 254 // -create GoudsmitSaundersonTable and init 257 // -create GoudsmitSaundersonTable and init its Mott-correction member if 255 // Mott-correction was required 258 // Mott-correction was required 256 if (IsMaster()) { 259 if (IsMaster()) { 257 // get the Mott-correction flag from EmPar 260 // get the Mott-correction flag from EmParameters 258 if (G4EmParameters::Instance()->UseMottCor 261 if (G4EmParameters::Instance()->UseMottCorrection()) { 259 fIsUseMottCorrection = true; 262 fIsUseMottCorrection = true; 260 } 263 } 261 // Mott-correction includes other way of P 264 // Mott-correction includes other way of PWA x-section corrections so deactivate it even if it was true 262 // when Mott-correction is activated by th 265 // when Mott-correction is activated by the user 263 if (fIsUseMottCorrection) { 266 if (fIsUseMottCorrection) { 264 fIsUsePWACorrection = false; 267 fIsUsePWACorrection = false; 265 } 268 } 266 // clear GS-table 269 // clear GS-table 267 if (fGSTable) { 270 if (fGSTable) { 268 delete fGSTable; 271 delete fGSTable; 269 fGSTable = nullptr; 272 fGSTable = nullptr; 270 } 273 } 271 // clear PWA corrections table if any 274 // clear PWA corrections table if any 272 if (fPWACorrection) { 275 if (fPWACorrection) { 273 delete fPWACorrection; 276 delete fPWACorrection; 274 fPWACorrection = nullptr; 277 fPWACorrection = nullptr; 275 } 278 } 276 // create GS-table 279 // create GS-table 277 G4bool isElectron = true; 280 G4bool isElectron = true; 278 if (p->GetPDGCharge()>0.) { 281 if (p->GetPDGCharge()>0.) { 279 isElectron = false; 282 isElectron = false; 280 } 283 } 281 fGSTable = new G4GoudsmitSaundersonTable(i 284 fGSTable = new G4GoudsmitSaundersonTable(isElectron); 282 // G4GSTable will be initialised: 285 // G4GSTable will be initialised: 283 // - Screened-Rutherford DCS based GS angu 286 // - Screened-Rutherford DCS based GS angular distributions will be loaded only if they are not there yet 284 // - Mott-correction will be initialised i 287 // - Mott-correction will be initialised if Mott-correction was requested to be used 285 fGSTable->SetOptionMottCorrection(fIsUseMo 288 fGSTable->SetOptionMottCorrection(fIsUseMottCorrection); 286 // - set PWA correction (correction to int 289 // - set PWA correction (correction to integrated quantites from Dirac-PWA) 287 fGSTable->SetOptionPWACorrection(fIsUsePWA 290 fGSTable->SetOptionPWACorrection(fIsUsePWACorrection); 288 // init 291 // init 289 fGSTable->Initialise(LowEnergyLimit(),High 292 fGSTable->Initialise(LowEnergyLimit(),HighEnergyLimit()); 290 // create PWA corrections table if it was 293 // create PWA corrections table if it was requested (and not disactivated because active Mott-correction) 291 if (fIsUsePWACorrection) { 294 if (fIsUsePWACorrection) { 292 fPWACorrection = new G4GSPWACorrections( << 295 fPWACorrection = new G4GSPWACorrections(); 293 fPWACorrection->Initialise(); 296 fPWACorrection->Initialise(); 294 } 297 } 295 } 298 } 296 fParticleChange = GetParticleChangeForMSC(p) << 297 } 299 } 298 300 299 301 300 void G4GoudsmitSaundersonMscModel::InitialiseL 302 void G4GoudsmitSaundersonMscModel::InitialiseLocal(const G4ParticleDefinition*, G4VEmModel* masterModel) { 301 fGSTable = static_cast<G4Goud 303 fGSTable = static_cast<G4GoudsmitSaundersonMscModel*>(masterModel)->GetGSTable(); 302 fIsUseMottCorrection = static_cast<G4Goud 304 fIsUseMottCorrection = static_cast<G4GoudsmitSaundersonMscModel*>(masterModel)->GetOptionMottCorrection(); 303 fIsUsePWACorrection = static_cast<G4Goud 305 fIsUsePWACorrection = static_cast<G4GoudsmitSaundersonMscModel*>(masterModel)->GetOptionPWACorrection(); 304 fPWACorrection = static_cast<G4Goud 306 fPWACorrection = static_cast<G4GoudsmitSaundersonMscModel*>(masterModel)->GetPWACorrection(); 305 } 307 } 306 308 307 309 308 // computes macroscopic first transport cross << 309 G4double G4GoudsmitSaundersonMscModel::CrossSe << 310 const << 311 G4dou << 312 G4dou << 313 G4dou << 314 G4double xsecTr1 = 0.; // cross section per << 315 // << 316 fLambda0 = 0.0; // elastic mean free path << 317 fLambda1 = 0.0; // first transport mean free << 318 fScrA = 0.0; // screening parameter << 319 fG1 = 0.0; // first transport coef. << 320 // use Moliere's screening (with Mott-corret << 321 G4double efEnergy = std::max(kineticEnergy, << 322 // total mometum square << 323 G4double pt2 = efEnergy*(efEnergy+2.0*el << 324 // beta square << 325 G4double beta2 = pt2/(pt2+electron_mass_c2 << 326 // current material index << 327 G4int matindx = (G4int)mat->GetIndex(); << 328 // Moliere's b_c << 329 G4double bc = fGSTable->GetMoliereBc(ma << 330 // get the Mott-correcton factors if Mott-co << 331 fMCtoScrA = 1.0; << 332 fMCtoQ1 = 1.0; << 333 fMCtoG2PerG1 = 1.0; << 334 G4double scpCor = 1.0; << 335 if (fIsUseMottCorrection) { << 336 fGSTable->GetMottCorrectionFactors(G4Log(e << 337 // ! no scattering power correction since << 338 // scpCor = fGSTable->ComputeScatteringPow << 339 } else if (fIsUsePWACorrection) { << 340 fPWACorrection->GetPWACorrectionFactors(G4 << 341 // scpCor = fGSTable->ComputeScatteringPow << 342 } << 343 // screening parameter: << 344 // - if Mott-corretioncorrection: the Screen << 345 // screening parameter gives back the (els << 346 // - if PWA correction: he Screened-Rutherfo << 347 // gives back the (elsepa) PWA first trans << 348 fScrA = fGSTable->GetMoliereXc2(matindx)/ << 349 // elastic mean free path in Geant4 internal << 350 // (if Mott-corretion: the corrected screeni << 351 // corrected with the screening parameter co << 352 fLambda0 = beta2*(1.+fScrA)*fMCtoScrA/bc/scp << 353 // first transport coefficient (if Mott-corr << 354 // consistent with the one used during the p << 355 fG1 = 2.0*fScrA*((1.0+fScrA)*G4Log(1.0/ << 356 // first transport mean free path << 357 fLambda1 = fLambda0/fG1; << 358 xsecTr1 = 1./fLambda1; << 359 return xsecTr1; << 360 } << 361 << 362 << 363 // gives back the first transport mean free pa 310 // gives back the first transport mean free path in internal G4 units 364 G4double 311 G4double 365 G4GoudsmitSaundersonMscModel::GetTransportMean 312 G4GoudsmitSaundersonMscModel::GetTransportMeanFreePath(const G4ParticleDefinition* /*partdef*/, 366 313 G4double kineticEnergy) { 367 // kinetic energy is assumed to be in Geant4 314 // kinetic energy is assumed to be in Geant4 internal energy unit which is MeV 368 G4double efEnergy = kineticEnergy; 315 G4double efEnergy = kineticEnergy; 369 // 316 // 370 const G4Material* mat = currentCouple->GetM 317 const G4Material* mat = currentCouple->GetMaterial(); 371 // 318 // 372 fLambda0 = 0.0; // elastic mean free path 319 fLambda0 = 0.0; // elastic mean free path 373 fLambda1 = 0.0; // first transport mean free 320 fLambda1 = 0.0; // first transport mean free path 374 fScrA = 0.0; // screening parameter 321 fScrA = 0.0; // screening parameter 375 fG1 = 0.0; // first transport coef. 322 fG1 = 0.0; // first transport coef. 376 323 377 // use Moliere's screening (with Mott-corret 324 // use Moliere's screening (with Mott-corretion if it was requested) 378 if (efEnergy<10.*CLHEP::eV) efEnergy = 10.* 325 if (efEnergy<10.*CLHEP::eV) efEnergy = 10.*CLHEP::eV; 379 // total mometum square 326 // total mometum square 380 G4double pt2 = efEnergy*(efEnergy+2.0*el 327 G4double pt2 = efEnergy*(efEnergy+2.0*electron_mass_c2); 381 // beta square 328 // beta square 382 G4double beta2 = pt2/(pt2+electron_mass_c2 329 G4double beta2 = pt2/(pt2+electron_mass_c2*electron_mass_c2); 383 // current material index 330 // current material index 384 G4int matindx = (G4int)mat->GetIndex(); << 331 G4int matindx = mat->GetIndex(); 385 // Moliere's b_c 332 // Moliere's b_c 386 G4double bc = fGSTable->GetMoliereBc(ma 333 G4double bc = fGSTable->GetMoliereBc(matindx); 387 // get the Mott-correcton factors if Mott-co 334 // get the Mott-correcton factors if Mott-correcton was requested by the user 388 fMCtoScrA = 1.0; 335 fMCtoScrA = 1.0; 389 fMCtoQ1 = 1.0; 336 fMCtoQ1 = 1.0; 390 fMCtoG2PerG1 = 1.0; 337 fMCtoG2PerG1 = 1.0; 391 G4double scpCor = 1.0; 338 G4double scpCor = 1.0; 392 if (fIsUseMottCorrection) { 339 if (fIsUseMottCorrection) { 393 fGSTable->GetMottCorrectionFactors(G4Log(e 340 fGSTable->GetMottCorrectionFactors(G4Log(efEnergy), beta2, matindx, fMCtoScrA, fMCtoQ1, fMCtoG2PerG1); 394 scpCor = fGSTable->ComputeScatteringPowerC 341 scpCor = fGSTable->ComputeScatteringPowerCorrection(currentCouple, efEnergy); 395 } else if (fIsUsePWACorrection) { 342 } else if (fIsUsePWACorrection) { 396 fPWACorrection->GetPWACorrectionFactors(G4 343 fPWACorrection->GetPWACorrectionFactors(G4Log(efEnergy), beta2, matindx, fMCtoScrA, fMCtoQ1, fMCtoG2PerG1); 397 // scpCor = fGSTable->ComputeScatteringPow 344 // scpCor = fGSTable->ComputeScatteringPowerCorrection(currentCouple, efEnergy); 398 } 345 } 399 // screening parameter: 346 // screening parameter: 400 // - if Mott-corretioncorrection: the Screen 347 // - if Mott-corretioncorrection: the Screened-Rutherford times Mott-corretion DCS with this 401 // screening parameter gives back the (els 348 // screening parameter gives back the (elsepa) PWA first transport cross section 402 // - if PWA correction: he Screened-Rutherfo 349 // - if PWA correction: he Screened-Rutherford DCS with this screening parameter 403 // gives back the (elsepa) PWA first trans 350 // gives back the (elsepa) PWA first transport cross section 404 fScrA = fGSTable->GetMoliereXc2(matindx)/ 351 fScrA = fGSTable->GetMoliereXc2(matindx)/(4.0*pt2*bc)*fMCtoScrA; 405 // elastic mean free path in Geant4 internal 352 // elastic mean free path in Geant4 internal lenght units: the neglected (1+screening parameter) term is corrected 406 // (if Mott-corretion: the corrected screeni 353 // (if Mott-corretion: the corrected screening parameter is used for this (1+A) correction + Moliere b_c is also 407 // corrected with the screening parameter co 354 // corrected with the screening parameter correction) 408 fLambda0 = beta2*(1.+fScrA)*fMCtoScrA/bc/scp 355 fLambda0 = beta2*(1.+fScrA)*fMCtoScrA/bc/scpCor; 409 // first transport coefficient (if Mott-corr 356 // first transport coefficient (if Mott-corretion: the corrected screening parameter is used (it will be fully 410 // consistent with the one used during the p 357 // consistent with the one used during the pre-computation of the Mott-correted GS angular distributions)) 411 fG1 = 2.0*fScrA*((1.0+fScrA)*G4Log(1.0/ 358 fG1 = 2.0*fScrA*((1.0+fScrA)*G4Log(1.0/fScrA+1.0)-1.0); 412 // first transport mean free path 359 // first transport mean free path 413 fLambda1 = fLambda0/fG1; 360 fLambda1 = fLambda0/fG1; 414 361 415 return fLambda1; 362 return fLambda1; 416 } 363 } 417 364 418 365 419 G4double 366 G4double 420 G4GoudsmitSaundersonMscModel::GetTransportMean 367 G4GoudsmitSaundersonMscModel::GetTransportMeanFreePathOnly(const G4ParticleDefinition* /*partdef*/, 421 368 G4double kineticEnergy) { 422 // kinetic energy is assumed to be in Geant4 369 // kinetic energy is assumed to be in Geant4 internal energy unit which is MeV 423 G4double efEnergy = kineticEnergy; 370 G4double efEnergy = kineticEnergy; 424 // 371 // 425 const G4Material* mat = currentCouple->GetM 372 const G4Material* mat = currentCouple->GetMaterial(); 426 // 373 // 427 G4double lambda0 = 0.0; // elastc mean free 374 G4double lambda0 = 0.0; // elastc mean free path 428 G4double lambda1 = 0.0; // first transport m 375 G4double lambda1 = 0.0; // first transport mean free path 429 G4double scrA = 0.0; // screening paramet 376 G4double scrA = 0.0; // screening parametr 430 G4double g1 = 0.0; // first transport m 377 G4double g1 = 0.0; // first transport mean free path 431 378 432 // use Moliere's screening (with Mott-corret 379 // use Moliere's screening (with Mott-corretion if it was requested) 433 if (efEnergy<10.*CLHEP::eV) efEnergy = 10.* 380 if (efEnergy<10.*CLHEP::eV) efEnergy = 10.*CLHEP::eV; 434 // total mometum square in Geant4 internal e 381 // total mometum square in Geant4 internal energy2 units which is MeV2 435 G4double pt2 = efEnergy*(efEnergy+2.0*el 382 G4double pt2 = efEnergy*(efEnergy+2.0*electron_mass_c2); 436 G4double beta2 = pt2/(pt2+electron_mass_c2 383 G4double beta2 = pt2/(pt2+electron_mass_c2*electron_mass_c2); 437 G4int matindx = (G4int)mat->GetIndex(); << 384 G4int matindx = mat->GetIndex(); 438 G4double bc = fGSTable->GetMoliereBc(ma 385 G4double bc = fGSTable->GetMoliereBc(matindx); 439 // get the Mott-correcton factors if Mott-co 386 // get the Mott-correcton factors if Mott-correcton was requested by the user 440 G4double mctoScrA = 1.0; 387 G4double mctoScrA = 1.0; 441 G4double mctoQ1 = 1.0; 388 G4double mctoQ1 = 1.0; 442 G4double mctoG2PerG1 = 1.0; 389 G4double mctoG2PerG1 = 1.0; 443 G4double scpCor = 1.0; 390 G4double scpCor = 1.0; 444 if (fIsUseMottCorrection) { 391 if (fIsUseMottCorrection) { 445 fGSTable->GetMottCorrectionFactors(G4Log(e 392 fGSTable->GetMottCorrectionFactors(G4Log(efEnergy), beta2, matindx, mctoScrA, mctoQ1, mctoG2PerG1); 446 scpCor = fGSTable->ComputeScatteringPowerC 393 scpCor = fGSTable->ComputeScatteringPowerCorrection(currentCouple, efEnergy); 447 } else if (fIsUsePWACorrection) { 394 } else if (fIsUsePWACorrection) { 448 fPWACorrection->GetPWACorrectionFactors(G4 395 fPWACorrection->GetPWACorrectionFactors(G4Log(efEnergy), beta2, matindx, mctoScrA, mctoQ1, mctoG2PerG1); 449 // scpCor = fGSTable->ComputeScatteringPow 396 // scpCor = fGSTable->ComputeScatteringPowerCorrection(currentCouple, efEnergy); 450 } 397 } 451 scrA = fGSTable->GetMoliereXc2(matindx)/( 398 scrA = fGSTable->GetMoliereXc2(matindx)/(4.0*pt2*bc)*mctoScrA; 452 // total elastic mean free path in Geant4 in 399 // total elastic mean free path in Geant4 internal lenght units 453 lambda0 = beta2*(1.+scrA)*mctoScrA/bc/scpCor 400 lambda0 = beta2*(1.+scrA)*mctoScrA/bc/scpCor; 454 g1 = 2.0*scrA*((1.0+scrA)*G4Log(1.0/scr 401 g1 = 2.0*scrA*((1.0+scrA)*G4Log(1.0/scrA+1.0)-1.0); 455 lambda1 = lambda0/g1; 402 lambda1 = lambda0/g1; 456 403 457 return lambda1; 404 return lambda1; 458 } 405 } 459 406 460 407 461 void G4GoudsmitSaundersonMscModel::StartTracki 408 void G4GoudsmitSaundersonMscModel::StartTracking(G4Track* track) { 462 SetParticle(track->GetDynamicParticle()->Get 409 SetParticle(track->GetDynamicParticle()->GetDefinition()); 463 firstStep = true; 410 firstStep = true; 464 tlimit = tgeom = rangeinit = geombig; 411 tlimit = tgeom = rangeinit = geombig; 465 rangeinit = 1.e+21; 412 rangeinit = 1.e+21; 466 } 413 } 467 414 468 415 469 G4double G4GoudsmitSaundersonMscModel::Compute 416 G4double G4GoudsmitSaundersonMscModel::ComputeTruePathLengthLimit(const G4Track& track, 470 417 G4double& currentMinimalStep) { 471 G4double skindepth = 0.; 418 G4double skindepth = 0.; 472 // 419 // 473 const G4DynamicParticle* dp = track.GetDynam 420 const G4DynamicParticle* dp = track.GetDynamicParticle(); 474 G4StepPoint* sp = track.GetStep( 421 G4StepPoint* sp = track.GetStep()->GetPreStepPoint(); 475 G4StepStatus stepStatus = sp->GetStepSta 422 G4StepStatus stepStatus = sp->GetStepStatus(); 476 currentCouple = track.GetMater 423 currentCouple = track.GetMaterialCutsCouple(); 477 SetCurrentCouple(currentCouple); 424 SetCurrentCouple(currentCouple); 478 currentMaterialIndex = (G4int)current << 425 currentMaterialIndex = currentCouple->GetMaterial()->GetIndex(); 479 currentKinEnergy = dp->GetKinetic 426 currentKinEnergy = dp->GetKineticEnergy(); 480 currentRange = GetRange(parti << 427 currentRange = GetRange(particle,currentKinEnergy,currentCouple); 481 dp->G << 482 // elastic and first transport mfp, screenin 428 // elastic and first transport mfp, screening parameter and G1 are also set 483 // (Mott-correction will be used if it was r 429 // (Mott-correction will be used if it was requested by the user) 484 fLambda1 = GetTransportMeanFreePath(particle 430 fLambda1 = GetTransportMeanFreePath(particle,currentKinEnergy); 485 // Set initial values: 431 // Set initial values: 486 // : lengths are initialised to currentMini 432 // : lengths are initialised to currentMinimalStep which is the true, minimum 487 // step length from all other physics 433 // step length from all other physics 488 fTheTrueStepLenght = currentMinimalStep; 434 fTheTrueStepLenght = currentMinimalStep; 489 fTheTransportDistance = currentMinimalStep; 435 fTheTransportDistance = currentMinimalStep; 490 fTheZPathLenght = currentMinimalStep; 436 fTheZPathLenght = currentMinimalStep; // will need to be converted 491 fTheDisplacementVector.set(0.,0.,0.); 437 fTheDisplacementVector.set(0.,0.,0.); 492 fTheNewDirection.set(0.,0.,1.); 438 fTheNewDirection.set(0.,0.,1.); 493 439 494 // Can everything be done in the step limit 440 // Can everything be done in the step limit phase ? 495 fIsEverythingWasDone = false; 441 fIsEverythingWasDone = false; 496 // Multiple scattering needs to be sample ? 442 // Multiple scattering needs to be sample ? 497 fIsMultipleSacettring = false; 443 fIsMultipleSacettring = false; 498 // Single scattering needs to be sample ? 444 // Single scattering needs to be sample ? 499 fIsSingleScattering = false; 445 fIsSingleScattering = false; 500 // Was zero deflection in multiple scatterin 446 // Was zero deflection in multiple scattering sampling ? 501 fIsNoScatteringInMSC = false; 447 fIsNoScatteringInMSC = false; 502 // Do not care about displacement in MSC sam 448 // Do not care about displacement in MSC sampling 503 // ( used only in the case of gIsOptimizatio 449 // ( used only in the case of gIsOptimizationOn = true) 504 fIsNoDisplace = false; 450 fIsNoDisplace = false; 505 // get pre-step point safety 451 // get pre-step point safety 506 presafety = sp->GetSafety(); 452 presafety = sp->GetSafety(); 507 // 453 // 508 fZeff = currentCouple->GetMaterial()->GetIon 454 fZeff = currentCouple->GetMaterial()->GetIonisation()->GetZeffective(); 509 // distance will take into account max-fluct 455 // distance will take into account max-fluct. 510 G4double distance = currentRange; 456 G4double distance = currentRange; 511 distance *= (1.20-fZeff*(1.62e-2-9.22e-5*fZe 457 distance *= (1.20-fZeff*(1.62e-2-9.22e-5*fZeff)); 512 // 458 // 513 // Possible optimization : if the distance i 459 // Possible optimization : if the distance is samller than the safety -> the 514 // particle will never leave this volume -> 460 // particle will never leave this volume -> dispalcement 515 // as the effect of multiple elastic scatter 461 // as the effect of multiple elastic scattering can be skipped 516 // Important : this optimization can cause p 462 // Important : this optimization can cause problems if one does scoring 517 // in a bigger volume since MSC won't be don 463 // in a bigger volume since MSC won't be done deep inside the volume when 518 // distance < safety so don't use optimized- 464 // distance < safety so don't use optimized-mode in such case. 519 if (gIsOptimizationOn && (distance<presafety 465 if (gIsOptimizationOn && (distance<presafety)) { 520 // Indicate that we need to do MSC after 466 // Indicate that we need to do MSC after transportation and no dispalcement. 521 fIsMultipleSacettring = true; 467 fIsMultipleSacettring = true; 522 fIsNoDisplace = true; 468 fIsNoDisplace = true; 523 } else if (steppingAlgorithm==fUseDistanceTo 469 } else if (steppingAlgorithm==fUseDistanceToBoundary) { 524 //Compute geomlimit (and presafety) : 470 //Compute geomlimit (and presafety) : 525 // - geomlimit will be: 471 // - geomlimit will be: 526 // == the straight line distance to the 472 // == the straight line distance to the boundary if currentRange is 527 // longer than that 473 // longer than that 528 // == a big value [geombig = 1.e50*mm] 474 // == a big value [geombig = 1.e50*mm] if currentRange is shorter than 529 // the straight line distance to the 475 // the straight line distance to the boundary 530 // - presafety will be updated as well 476 // - presafety will be updated as well 531 // So the particle can travell 'gemlimit' 477 // So the particle can travell 'gemlimit' distance (along a straight 532 // line!) in its current direction: 478 // line!) in its current direction: 533 // (1) before reaching a boundary (geomli 479 // (1) before reaching a boundary (geomlimit < geombig) OR 534 // (2) before reaching its current range 480 // (2) before reaching its current range (geomlimit == geombig) 535 geomlimit = ComputeGeomLimit(track, presaf 481 geomlimit = ComputeGeomLimit(track, presafety, currentRange); 536 // Record that the particle is on a bounda 482 // Record that the particle is on a boundary 537 if ( (stepStatus==fGeomBoundary) || (stepS 483 if ( (stepStatus==fGeomBoundary) || (stepStatus==fUndefined && presafety==0.0)) { 538 fIsWasOnBoundary = true; 484 fIsWasOnBoundary = true; 539 } 485 } 540 // Set skin depth = skin x elastic_mean_fr 486 // Set skin depth = skin x elastic_mean_free_path 541 skindepth = skin*fLambda0; 487 skindepth = skin*fLambda0; 542 // Init the flag that indicates that the p 488 // Init the flag that indicates that the particle are within a skindepth 543 // distance from a boundary 489 // distance from a boundary 544 fIsInsideSkin = false; 490 fIsInsideSkin = false; 545 // Check if we can try Single Scattering b 491 // Check if we can try Single Scattering because we are within skindepth 546 // distance from/to a boundary OR the curr 492 // distance from/to a boundary OR the current minimum true-step-length is 547 // shorter than skindepth. NOTICE: the lat 493 // shorter than skindepth. NOTICE: the latest has only efficieny reasons 548 // because the MSC angular sampling is fin 494 // because the MSC angular sampling is fine for any short steps but much 549 // faster to try single scattering in case 495 // faster to try single scattering in case of short steps. 550 if ((stepStatus==fGeomBoundary) || (presaf 496 if ((stepStatus==fGeomBoundary) || (presafety<skindepth) || (fTheTrueStepLenght<skindepth)) { 551 // check if we are within skindepth dist 497 // check if we are within skindepth distance from a boundary 552 if ((stepStatus == fGeomBoundary) || (pr 498 if ((stepStatus == fGeomBoundary) || (presafety < skindepth)) { 553 fIsInsideSkin = true; 499 fIsInsideSkin = true; 554 fIsWasOnBoundary = true; 500 fIsWasOnBoundary = true; 555 } 501 } 556 //Try single scattering: 502 //Try single scattering: 557 // - sample distance to next single scat 503 // - sample distance to next single scattering interaction (sslimit) 558 // - compare to current minimum length 504 // - compare to current minimum length 559 // == if sslimit is the shorter: 505 // == if sslimit is the shorter: 560 // - set the step length to ssl 506 // - set the step length to sslimit 561 // - indicate that single scatt 507 // - indicate that single scattering needs to be done 562 // == else : nothing to do 508 // == else : nothing to do 563 //- in both cases, the step length was v 509 //- in both cases, the step length was very short so geometrical and 564 // true path length are the same 510 // true path length are the same 565 G4double sslimit = -1.*fLambda0*G4Log(G4 511 G4double sslimit = -1.*fLambda0*G4Log(G4UniformRand()); 566 // compare to current minimum step lengt 512 // compare to current minimum step length 567 if (sslimit<fTheTrueStepLenght) { 513 if (sslimit<fTheTrueStepLenght) { 568 fTheTrueStepLenght = sslimit; 514 fTheTrueStepLenght = sslimit; 569 fIsSingleScattering = true; 515 fIsSingleScattering = true; 570 } 516 } 571 // short step -> true step length equal 517 // short step -> true step length equal to geometrical path length 572 fTheZPathLenght = fTheTrueStepLeng 518 fTheZPathLenght = fTheTrueStepLenght; 573 // Set taht everything is done in step-l 519 // Set taht everything is done in step-limit phase so no MSC call 574 // We will check if we need to perform t 520 // We will check if we need to perform the single-scattering angular 575 // sampling i.e. if single elastic scatt 521 // sampling i.e. if single elastic scattering was the winer! 576 fIsEverythingWasDone = true; 522 fIsEverythingWasDone = true; 577 } else { 523 } else { 578 // After checking we know that we cannot 524 // After checking we know that we cannot try single scattering so we will 579 // need to make an MSC step 525 // need to make an MSC step 580 // Indicate that we need to make and MSC 526 // Indicate that we need to make and MSC step. We do not check if we can 581 // do it now i.e. if presafety>final_tru 527 // do it now i.e. if presafety>final_true_step_length so we let the 582 // fIsEverythingWasDone = false which in 528 // fIsEverythingWasDone = false which indicates that we will perform 583 // MSC after transportation. 529 // MSC after transportation. 584 fIsMultipleSacettring = true; 530 fIsMultipleSacettring = true; 585 // Init the first-real-step falg: it wil 531 // Init the first-real-step falg: it will indicate if we do the first 586 // non-single scattering step in this vo 532 // non-single scattering step in this volume with this particle 587 fIsFirstRealStep = false; 533 fIsFirstRealStep = false; 588 // If previously the partcile was on bou 534 // If previously the partcile was on boundary it was within skin as 589 // well. When it is not within skin anym 535 // well. When it is not within skin anymore it has just left the skin 590 // so we make the first real MSC step wi 536 // so we make the first real MSC step with the particle. 591 if (fIsWasOnBoundary && !fIsInsideSkin) 537 if (fIsWasOnBoundary && !fIsInsideSkin) { 592 // reset the 'was on boundary' indicat 538 // reset the 'was on boundary' indicator flag 593 fIsWasOnBoundary = false; 539 fIsWasOnBoundary = false; 594 fIsFirstRealStep = true; 540 fIsFirstRealStep = true; 595 } 541 } 596 // If this is the first-real msc step (t 542 // If this is the first-real msc step (the partcile has just left the 597 // skin) or this is the first step with 543 // skin) or this is the first step with the particle (was born or 598 // primary): 544 // primary): 599 // - set the initial range that will b 545 // - set the initial range that will be used later to limit its step 600 // (only in this volume, because aft 546 // (only in this volume, because after boundary crossing at the 601 // first-real MSC step we will reset 547 // first-real MSC step we will reset) 602 // - don't let the partcile to cross th 548 // - don't let the partcile to cross the volume just in one step 603 if (firstStep || fIsFirstRealStep || ran 549 if (firstStep || fIsFirstRealStep || rangeinit>1.e+20) { 604 rangeinit = currentRange; 550 rangeinit = currentRange; 605 // If geomlimit < geombig than the par 551 // If geomlimit < geombig than the particle might reach the boundary 606 // along its initial direction before 552 // along its initial direction before losing its energy (in this step) 607 // Otherwise we can be sure that the p 553 // Otherwise we can be sure that the particle will lose it energy 608 // before reaching the boundary along 554 // before reaching the boundary along a starigth line so there is no 609 // geometrical limit appalied. [Howeve 555 // geometrical limit appalied. [However, tgeom is set only in the 610 // first or the first-real MSC step. A 556 // first or the first-real MSC step. After the first or first real 611 // MSC step the direction will change 557 // MSC step the direction will change tgeom won't guaranty anything! 612 // But we will try to end up within sk 558 // But we will try to end up within skindepth from the boundary using 613 // the actual value of geomlimit(See l 559 // the actual value of geomlimit(See later at step reduction close to 614 // boundary).] 560 // boundary).] 615 if (geomlimit<geombig) { 561 if (geomlimit<geombig) { 616 // transfrom straight line distance 562 // transfrom straight line distance to the boundary to real step 617 // length based on the mean values ( 563 // length based on the mean values (using the prestep point 618 // first-transport mean free path i. 564 // first-transport mean free path i.e. no energy loss correction) 619 if ((1.-geomlimit/fLambda1)> 0.) { 565 if ((1.-geomlimit/fLambda1)> 0.) { 620 geomlimit = -fLambda1*G4Log(1.-geo 566 geomlimit = -fLambda1*G4Log(1.-geomlimit/fLambda1); 621 } 567 } 622 // the 2-different case that could l 568 // the 2-different case that could lead us here 623 if (firstStep) { 569 if (firstStep) { 624 tgeom = 2.*geomlimit/facgeom; 570 tgeom = 2.*geomlimit/facgeom; 625 } else { 571 } else { 626 tgeom = geomlimit/facgeom; 572 tgeom = geomlimit/facgeom; 627 } 573 } 628 } else { 574 } else { 629 tgeom = geombig; 575 tgeom = geombig; 630 } 576 } 631 } 577 } 632 // True step length limit from range fac 578 // True step length limit from range factor. Noteice, that the initial 633 // range is used that was set at the fir 579 // range is used that was set at the first step or first-real MSC step 634 // in this volume with this particle. 580 // in this volume with this particle. 635 tlimit = facrange*rangeinit; 581 tlimit = facrange*rangeinit; 636 // Take the minimum of the true step len 582 // Take the minimum of the true step length limits coming from 637 // geometrical constraint or range-facto 583 // geometrical constraint or range-factor limitation 638 tlimit = std::min(tlimit,tgeom); 584 tlimit = std::min(tlimit,tgeom); 639 // Step reduction close to boundary: we 585 // Step reduction close to boundary: we try to end up within skindepth 640 // from the boundary ( Notice: in case o 586 // from the boundary ( Notice: in case of mag. field it might not work 641 // because geomlimit is the straigth lin 587 // because geomlimit is the straigth line distance to the boundary in 642 // the currect direction (if geomlimit<g 588 // the currect direction (if geomlimit<geombig) and mag. field can 643 // change the initial direction. So te p 589 // change the initial direction. So te particle might hit some boundary 644 // before in a different direction. Howe 590 // before in a different direction. However, here we restrict the true 645 // path length to this (straight line) l 591 // path length to this (straight line) lenght so the corresponding 646 // transport distance (straight line) wi 592 // transport distance (straight line) will be even shorter than 647 // geomlimit-0.999*skindepth after the c 593 // geomlimit-0.999*skindepth after the change of true->geom. 648 if (geomlimit<geombig) { 594 if (geomlimit<geombig) { 649 tlimit = std::min(tlimit, geomlimit-0. 595 tlimit = std::min(tlimit, geomlimit-0.999*skindepth); 650 } 596 } 651 // randomize 1st step or 1st 'normal' st 597 // randomize 1st step or 1st 'normal' step in volume 652 if (firstStep || fIsFirstRealStep) { 598 if (firstStep || fIsFirstRealStep) { 653 fTheTrueStepLenght = std::min(fTheTrue 599 fTheTrueStepLenght = std::min(fTheTrueStepLenght, Randomizetlimit()); 654 } else { 600 } else { 655 fTheTrueStepLenght = std::min(fTheTrue 601 fTheTrueStepLenght = std::min(fTheTrueStepLenght, tlimit); 656 } 602 } 657 } 603 } 658 } else if (steppingAlgorithm==fUseSafetyPlus 604 } else if (steppingAlgorithm==fUseSafetyPlus) { // THE ERROR_FREE stepping alg. 659 presafety = ComputeSafety(sp->GetPosition 605 presafety = ComputeSafety(sp->GetPosition(),fTheTrueStepLenght); 660 geomlimit = presafety; 606 geomlimit = presafety; 661 // Set skin depth = skin x elastic_mean_fr 607 // Set skin depth = skin x elastic_mean_free_path 662 skindepth = skin*fLambda0; 608 skindepth = skin*fLambda0; 663 // Check if we can try Single Scattering b 609 // Check if we can try Single Scattering because we are within skindepth 664 // distance from/to a boundary OR the curr 610 // distance from/to a boundary OR the current minimum true-step-length is 665 // shorter than skindepth. NOTICE: the lat 611 // shorter than skindepth. NOTICE: the latest has only efficieny reasons 666 // because the MSC angular sampling is fin 612 // because the MSC angular sampling is fine for any short steps but much 667 // faster to try single scattering in case 613 // faster to try single scattering in case of short steps. 668 if ((stepStatus==fGeomBoundary) || (presaf 614 if ((stepStatus==fGeomBoundary) || (presafety<skindepth) || (fTheTrueStepLenght<skindepth)) { 669 //Try single scattering: 615 //Try single scattering: 670 // - sample distance to next single scat 616 // - sample distance to next single scattering interaction (sslimit) 671 // - compare to current minimum length 617 // - compare to current minimum length 672 // == if sslimit is the shorter: 618 // == if sslimit is the shorter: 673 // - set the step length to ssl 619 // - set the step length to sslimit 674 // - indicate that single scatt 620 // - indicate that single scattering needs to be done 675 // == else : nothing to do 621 // == else : nothing to do 676 //- in both cases, the step length was v 622 //- in both cases, the step length was very short so geometrical and 677 // true path length are the same 623 // true path length are the same 678 G4double sslimit = -1.*fLambda0*G4Log(G4 624 G4double sslimit = -1.*fLambda0*G4Log(G4UniformRand()); 679 // compare to current minimum step lengt 625 // compare to current minimum step length 680 if (sslimit<fTheTrueStepLenght) { 626 if (sslimit<fTheTrueStepLenght) { 681 fTheTrueStepLenght = sslimit; 627 fTheTrueStepLenght = sslimit; 682 fIsSingleScattering = true; 628 fIsSingleScattering = true; 683 } 629 } 684 // short step -> true step length equal 630 // short step -> true step length equal to geometrical path length 685 fTheZPathLenght = fTheTrueStepLeng 631 fTheZPathLenght = fTheTrueStepLenght; 686 // Set taht everything is done in step-l 632 // Set taht everything is done in step-limit phase so no MSC call 687 // We will check if we need to perform t 633 // We will check if we need to perform the single-scattering angular 688 // sampling i.e. if single elastic scatt 634 // sampling i.e. if single elastic scattering was the winer! 689 fIsEverythingWasDone = true; 635 fIsEverythingWasDone = true; 690 } else { 636 } else { 691 // After checking we know that we cannot 637 // After checking we know that we cannot try single scattering so we will 692 // need to make an MSC step 638 // need to make an MSC step 693 // Indicate that we need to make and MSC 639 // Indicate that we need to make and MSC step. 694 fIsMultipleSacettring = true; 640 fIsMultipleSacettring = true; 695 fIsEverythingWasDone = true; 641 fIsEverythingWasDone = true; 696 // limit from range factor 642 // limit from range factor 697 fTheTrueStepLenght = std::min(fTheTru 643 fTheTrueStepLenght = std::min(fTheTrueStepLenght, facrange*currentRange); 698 // never let the particle go further tha 644 // never let the particle go further than the safety if we are out of the skin 699 // if we are here we are out of the skin 645 // if we are here we are out of the skin, presafety > 0. 700 if (fTheTrueStepLenght>presafety) { 646 if (fTheTrueStepLenght>presafety) { 701 fTheTrueStepLenght = std::min(fTheTrue 647 fTheTrueStepLenght = std::min(fTheTrueStepLenght, presafety); 702 } 648 } 703 // make sure that we are still within th 649 // make sure that we are still within the aplicability of condensed histry model 704 // i.e. true step length is not longer t 650 // i.e. true step length is not longer than first transport mean free path. 705 // We schould take into account energy l 651 // We schould take into account energy loss along 0.5x lambda_transport1 706 // step length as well. So let it 0.5 x 652 // step length as well. So let it 0.5 x lambda_transport1 707 fTheTrueStepLenght = std::min(fTheTrueSt 653 fTheTrueStepLenght = std::min(fTheTrueStepLenght, fLambda1*0.5); 708 } 654 } 709 } else { 655 } else { 710 // This is the default stepping algorithm: 656 // This is the default stepping algorithm: the fastest but the least 711 // accurate that corresponds to fUseSafety 657 // accurate that corresponds to fUseSafety in Urban model. Note, that GS 712 // model can handle any short steps so we 658 // model can handle any short steps so we do not need the minimum limits 713 // 659 // 714 // NO single scattering in case of skin or 660 // NO single scattering in case of skin or short steps (by defult the MSC 715 // model will be single or even no scatter 661 // model will be single or even no scattering in case of short steps 716 // compared to the elastic mean free path. 662 // compared to the elastic mean free path.) 717 // 663 // 718 // indicate that MSC needs to be done (alw 664 // indicate that MSC needs to be done (always and always after transportation) 719 fIsMultipleSacettring = true; 665 fIsMultipleSacettring = true; 720 if (stepStatus!=fGeomBoundary) { 666 if (stepStatus!=fGeomBoundary) { 721 presafety = ComputeSafety(sp->GetPositio 667 presafety = ComputeSafety(sp->GetPosition(),fTheTrueStepLenght); 722 } 668 } 723 // Far from boundary-> in optimized mode d 669 // Far from boundary-> in optimized mode do not sample dispalcement. 724 if ((distance<presafety) && (gIsOptimizati 670 if ((distance<presafety) && (gIsOptimizationOn)) { 725 fIsNoDisplace = true; 671 fIsNoDisplace = true; 726 } else { 672 } else { 727 // Urban like 673 // Urban like 728 if (firstStep || (stepStatus==fGeomBound 674 if (firstStep || (stepStatus==fGeomBoundary) || rangeinit>1.e+20) { 729 rangeinit = currentRange; 675 rangeinit = currentRange; 730 fr = facrange; 676 fr = facrange; 731 // We don't use this: we won't converge to the 677 // We don't use this: we won't converge to the single scattering results with 732 // decreasing range-factor. 678 // decreasing range-factor. 733 // rangeinit = std::max(rangeinit 679 // rangeinit = std::max(rangeinit, fLambda1); 734 // if(fLambda1 > lambdalimit) { 680 // if(fLambda1 > lambdalimit) { 735 // fr *= (0.75+0.25*fLambda1/la 681 // fr *= (0.75+0.25*fLambda1/lambdalimit); 736 // } 682 // } 737 683 738 } 684 } 739 //step limit 685 //step limit 740 tlimit = std::max(fr*rangeinit, facsafet 686 tlimit = std::max(fr*rangeinit, facsafety*presafety); 741 // first step randomization 687 // first step randomization 742 if (firstStep || stepStatus==fGeomBounda 688 if (firstStep || stepStatus==fGeomBoundary) { 743 fTheTrueStepLenght = std::min(fTheTrue 689 fTheTrueStepLenght = std::min(fTheTrueStepLenght, Randomizetlimit()); 744 } else { 690 } else { 745 fTheTrueStepLenght = std::min(fTheTrue 691 fTheTrueStepLenght = std::min(fTheTrueStepLenght, tlimit); 746 } 692 } 747 } 693 } 748 } 694 } 749 // 695 // 750 // unset first-step 696 // unset first-step 751 firstStep =false; 697 firstStep =false; 752 // performe single scattering, multiple scat 698 // performe single scattering, multiple scattering if this later can be done safely here 753 if (fIsEverythingWasDone) { 699 if (fIsEverythingWasDone) { 754 if (fIsSingleScattering) { 700 if (fIsSingleScattering) { 755 // sample single scattering 701 // sample single scattering 756 //G4double ekin = 0.5*(currentKinEnerg 702 //G4double ekin = 0.5*(currentKinEnergy + GetEnergy(particle,currentRange-fTheTrueStepLenght,currentCouple)); 757 G4double lekin = G4Log(currentKinEnergy 703 G4double lekin = G4Log(currentKinEnergy); 758 G4double pt2 = currentKinEnergy*(curr 704 G4double pt2 = currentKinEnergy*(currentKinEnergy+2.0*CLHEP::electron_mass_c2); 759 G4double beta2 = pt2/(pt2+CLHEP::electr 705 G4double beta2 = pt2/(pt2+CLHEP::electron_mass_c2*CLHEP::electron_mass_c2); 760 G4double cost = fGSTable->SingleScatte 706 G4double cost = fGSTable->SingleScattering(1., fScrA, lekin, beta2, currentMaterialIndex); 761 // protection 707 // protection 762 if (cost<-1.) cost = -1.; 708 if (cost<-1.) cost = -1.; 763 if (cost> 1.) cost = 1.; 709 if (cost> 1.) cost = 1.; 764 // compute sint 710 // compute sint 765 G4double dum = 1.-cost; 711 G4double dum = 1.-cost; 766 G4double sint = std::sqrt(dum*(2.-dum) 712 G4double sint = std::sqrt(dum*(2.-dum)); 767 G4double phi = CLHEP::twopi*G4Uniform 713 G4double phi = CLHEP::twopi*G4UniformRand(); 768 G4double sinPhi = std::sin(phi); 714 G4double sinPhi = std::sin(phi); 769 G4double cosPhi = std::cos(phi); 715 G4double cosPhi = std::cos(phi); 770 fTheNewDirection.set(sint*cosPhi,sint*si 716 fTheNewDirection.set(sint*cosPhi,sint*sinPhi,cost); 771 } else if (fIsMultipleSacettring) { 717 } else if (fIsMultipleSacettring) { 772 // sample multiple scattering 718 // sample multiple scattering 773 SampleMSC(); // fTheZPathLenght, fTheDis 719 SampleMSC(); // fTheZPathLenght, fTheDisplacementVector and fTheNewDirection will be set 774 } // and if single scattering but it was l 720 } // and if single scattering but it was longer => nothing to do 775 } //else { do nothing here but after transpo 721 } //else { do nothing here but after transportation 776 // 722 // 777 return ConvertTrueToGeom(fTheTrueStepLenght, 723 return ConvertTrueToGeom(fTheTrueStepLenght,currentMinimalStep); 778 } 724 } 779 725 780 726 781 G4double G4GoudsmitSaundersonMscModel::Compute 727 G4double G4GoudsmitSaundersonMscModel::ComputeGeomPathLength(G4double) { 782 // convert true ->geom 728 // convert true ->geom 783 // It is called from the step limitation Com 729 // It is called from the step limitation ComputeTruePathLengthLimit if 784 // !fIsEverythingWasDone but protect: 730 // !fIsEverythingWasDone but protect: 785 par1 = -1.; 731 par1 = -1.; 786 par2 = par3 = 0.; 732 par2 = par3 = 0.; 787 // if fIsEverythingWasDone = TRUE => fTheZP 733 // if fIsEverythingWasDone = TRUE => fTheZPathLenght is already set 788 // so return with the already known value 734 // so return with the already known value 789 // Otherwise: 735 // Otherwise: 790 if (!fIsEverythingWasDone) { 736 if (!fIsEverythingWasDone) { 791 // this correction needed to run MSC with 737 // this correction needed to run MSC with eIoni and eBrem inactivated 792 // and makes no harm for a normal run 738 // and makes no harm for a normal run 793 fTheTrueStepLenght = std::min(fTheTrueStep 739 fTheTrueStepLenght = std::min(fTheTrueStepLenght,currentRange); 794 // do the true -> geom transformation 740 // do the true -> geom transformation 795 fTheZPathLenght = fTheTrueStepLenght; 741 fTheZPathLenght = fTheTrueStepLenght; 796 // z = t for very small true-path-length 742 // z = t for very small true-path-length 797 if (fTheTrueStepLenght<tlimitminfix2) { 743 if (fTheTrueStepLenght<tlimitminfix2) { 798 return fTheZPathLenght; 744 return fTheZPathLenght; 799 } 745 } 800 G4double tau = fTheTrueStepLenght/fLambda1 746 G4double tau = fTheTrueStepLenght/fLambda1; 801 if (tau<=tausmall) { 747 if (tau<=tausmall) { 802 fTheZPathLenght = std::min(fTheTrueStepL 748 fTheZPathLenght = std::min(fTheTrueStepLenght, fLambda1); 803 } else if (fTheTrueStepLenght<currentRang 749 } else if (fTheTrueStepLenght<currentRange*dtrl) { 804 if (tau<taulim) fTheZPathLenght = fTheTr 750 if (tau<taulim) fTheZPathLenght = fTheTrueStepLenght*(1.-0.5*tau) ; 805 else fTheZPathLenght = fLambd 751 else fTheZPathLenght = fLambda1*(1.-G4Exp(-tau)); 806 } else if (currentKinEnergy<mass || fTheTr 752 } else if (currentKinEnergy<mass || fTheTrueStepLenght==currentRange) { 807 par1 = 1./currentRange ; // alpha =1 753 par1 = 1./currentRange ; // alpha =1/range_init for Ekin<mass 808 par2 = 1./(par1*fLambda1) ; // 1/(alpha 754 par2 = 1./(par1*fLambda1) ; // 1/(alphaxlambda01) 809 par3 = 1.+par2 ; // 1+1/ 755 par3 = 1.+par2 ; // 1+1/ 810 if (fTheTrueStepLenght<currentRange) { 756 if (fTheTrueStepLenght<currentRange) { 811 fTheZPathLenght = 1./(par1*par3) * (1. 757 fTheZPathLenght = 1./(par1*par3) * (1.-std::pow(1.-par1*fTheTrueStepLenght,par3)); 812 } else { 758 } else { 813 fTheZPathLenght = 1./(par1*par3); 759 fTheZPathLenght = 1./(par1*par3); 814 } 760 } 815 } else { 761 } else { 816 G4double rfin = std::max(currentRange 762 G4double rfin = std::max(currentRange-fTheTrueStepLenght, 0.01*currentRange); 817 G4double T1 = GetEnergy(particle,rf 763 G4double T1 = GetEnergy(particle,rfin,currentCouple); 818 G4double lambda1 = GetTransportMeanFreeP 764 G4double lambda1 = GetTransportMeanFreePathOnly(particle,T1); 819 // 765 // 820 par1 = (fLambda1-lambda1)/(fLambda1*fThe 766 par1 = (fLambda1-lambda1)/(fLambda1*fTheTrueStepLenght); // alpha 821 par2 = 1./(par1*fLambda1); 767 par2 = 1./(par1*fLambda1); 822 par3 = 1.+par2 ; 768 par3 = 1.+par2 ; 823 G4Pow *g4calc = G4Pow::GetInstance(); 769 G4Pow *g4calc = G4Pow::GetInstance(); 824 fTheZPathLenght = 1./(par1*par3) * (1.-g 770 fTheZPathLenght = 1./(par1*par3) * (1.-g4calc->powA(1.-par1*fTheTrueStepLenght,par3)); 825 } 771 } 826 } 772 } 827 fTheZPathLenght = std::min(fTheZPathLenght, 773 fTheZPathLenght = std::min(fTheZPathLenght, fLambda1); 828 // 774 // 829 return fTheZPathLenght; 775 return fTheZPathLenght; 830 } 776 } 831 777 832 778 833 G4double G4GoudsmitSaundersonMscModel::Compute 779 G4double G4GoudsmitSaundersonMscModel::ComputeTrueStepLength(G4double geomStepLength) { 834 // init 780 // init 835 fIsEndedUpOnBoundary = false; 781 fIsEndedUpOnBoundary = false; 836 // step defined other than transportation 782 // step defined other than transportation 837 if (geomStepLength==fTheZPathLenght) { 783 if (geomStepLength==fTheZPathLenght) { 838 return fTheTrueStepLenght; 784 return fTheTrueStepLenght; 839 } 785 } 840 // else :: 786 // else :: 841 // - set the flag that transportation was th 787 // - set the flag that transportation was the winer so DoNothin in DOIT !! 842 // - convert geom -> true by using the mean 788 // - convert geom -> true by using the mean value 843 fIsEndedUpOnBoundary = true; // OR LAST STEP 789 fIsEndedUpOnBoundary = true; // OR LAST STEP 844 fTheZPathLenght = geomStepLength; 790 fTheZPathLenght = geomStepLength; 845 // was a short single scattering step 791 // was a short single scattering step 846 if (fIsEverythingWasDone && !fIsMultipleSace 792 if (fIsEverythingWasDone && !fIsMultipleSacettring) { 847 fTheTrueStepLenght = geomStepLength; 793 fTheTrueStepLenght = geomStepLength; 848 return fTheTrueStepLenght; 794 return fTheTrueStepLenght; 849 } 795 } 850 // t = z for very small step 796 // t = z for very small step 851 if (geomStepLength<tlimitminfix2) { 797 if (geomStepLength<tlimitminfix2) { 852 fTheTrueStepLenght = geomStepLength; 798 fTheTrueStepLenght = geomStepLength; 853 // recalculation 799 // recalculation 854 } else { 800 } else { 855 G4double tlength = geomStepLength; 801 G4double tlength = geomStepLength; 856 if (geomStepLength>fLambda1*tausmall) { 802 if (geomStepLength>fLambda1*tausmall) { 857 if (par1< 0.) { 803 if (par1< 0.) { 858 tlength = -fLambda1*G4Log(1.-geomStepL 804 tlength = -fLambda1*G4Log(1.-geomStepLength/fLambda1) ; 859 } else { 805 } else { 860 if (par1*par3*geomStepLength<1.) { 806 if (par1*par3*geomStepLength<1.) { 861 G4Pow *g4calc = G4Pow::GetInstance() 807 G4Pow *g4calc = G4Pow::GetInstance(); 862 tlength = (1.-g4calc->powA( 1.-par1* 808 tlength = (1.-g4calc->powA( 1.-par1*par3*geomStepLength,1./par3))/par1; 863 } else { 809 } else { 864 tlength = currentRange; 810 tlength = currentRange; 865 } 811 } 866 } 812 } 867 if (tlength<geomStepLength || tlength>fT 813 if (tlength<geomStepLength || tlength>fTheTrueStepLenght) { 868 tlength = geomStepLength; 814 tlength = geomStepLength; 869 } 815 } 870 } 816 } 871 fTheTrueStepLenght = tlength; 817 fTheTrueStepLenght = tlength; 872 } 818 } 873 // 819 // 874 return fTheTrueStepLenght; 820 return fTheTrueStepLenght; 875 } 821 } 876 822 877 G4ThreeVector& 823 G4ThreeVector& 878 G4GoudsmitSaundersonMscModel::SampleScattering 824 G4GoudsmitSaundersonMscModel::SampleScattering(const G4ThreeVector& oldDirection, G4double) { 879 if (steppingAlgorithm==fUseDistanceToBoundar 825 if (steppingAlgorithm==fUseDistanceToBoundary && fIsEverythingWasDone && fIsSingleScattering) { 880 // single scattering was and scattering ha 826 // single scattering was and scattering happend 881 fTheNewDirection.rotateUz(oldDirection); 827 fTheNewDirection.rotateUz(oldDirection); 882 fParticleChange->ProposeMomentumDirection( 828 fParticleChange->ProposeMomentumDirection(fTheNewDirection); 883 return fTheDisplacementVector; 829 return fTheDisplacementVector; 884 } else if (steppingAlgorithm==fUseSafetyPlus 830 } else if (steppingAlgorithm==fUseSafetyPlus) { // error-free stepping 885 if (fIsEndedUpOnBoundary) { // do nothing 831 if (fIsEndedUpOnBoundary) { // do nothing on the boundary 886 return fTheDisplacementVector; 832 return fTheDisplacementVector; 887 } else if (fIsEverythingWasDone) { // evry 833 } else if (fIsEverythingWasDone) { // evrything is done if not optimizations case !!! 888 // check single scattering and see if it 834 // check single scattering and see if it happened 889 if (fIsSingleScattering) { 835 if (fIsSingleScattering) { 890 fTheNewDirection.rotateUz(oldDirection 836 fTheNewDirection.rotateUz(oldDirection); 891 fParticleChange->ProposeMomentumDirect 837 fParticleChange->ProposeMomentumDirection(fTheNewDirection); 892 return fTheDisplacementVector; 838 return fTheDisplacementVector; 893 } 839 } 894 // check if multiple scattering happened 840 // check if multiple scattering happened and do things only if scattering was really happening 895 if (fIsMultipleSacettring && !fIsNoScatt 841 if (fIsMultipleSacettring && !fIsNoScatteringInMSC) { 896 fTheNewDirection.rotateUz(oldDirect 842 fTheNewDirection.rotateUz(oldDirection); 897 fTheDisplacementVector.rotateUz(old 843 fTheDisplacementVector.rotateUz(oldDirection); 898 fParticleChange->ProposeMomentumDir 844 fParticleChange->ProposeMomentumDirection(fTheNewDirection); 899 } 845 } 900 // The only thing that could happen if w 846 // The only thing that could happen if we are here (fUseSafety and fIsEverythingWasDone) 901 // is that single scattering was tried 847 // is that single scattering was tried but did not win so scattering did not happen. 902 // So no displacement and no scattering 848 // So no displacement and no scattering 903 return fTheDisplacementVector; 849 return fTheDisplacementVector; 904 } 850 } 905 // 851 // 906 // The only thing that could still happen 852 // The only thing that could still happen with fUseSafetyPlus is that we are in the 907 // optimization branch: so sample MSC angl 853 // optimization branch: so sample MSC angle here (no displacement) 908 } 854 } 909 //else MSC needs to be done here 855 //else MSC needs to be done here 910 SampleMSC(); 856 SampleMSC(); 911 if (!fIsNoScatteringInMSC) { 857 if (!fIsNoScatteringInMSC) { 912 fTheNewDirection.rotateUz(oldDirection); 858 fTheNewDirection.rotateUz(oldDirection); 913 fParticleChange->ProposeMomentumDirection( 859 fParticleChange->ProposeMomentumDirection(fTheNewDirection); 914 if (!fIsNoDisplace) { 860 if (!fIsNoDisplace) { 915 fTheDisplacementVector.rotateUz(oldDirec 861 fTheDisplacementVector.rotateUz(oldDirection); 916 } 862 } 917 } 863 } 918 // 864 // 919 return fTheDisplacementVector; 865 return fTheDisplacementVector; 920 } 866 } 921 867 922 868 923 void G4GoudsmitSaundersonMscModel::SampleMSC() 869 void G4GoudsmitSaundersonMscModel::SampleMSC() { 924 fIsNoScatteringInMSC = false; 870 fIsNoScatteringInMSC = false; 925 // kinetic energy is assumed to be in Geant4 871 // kinetic energy is assumed to be in Geant4 internal energy unit which is MeV 926 G4double kineticEnergy = currentKinEnergy; 872 G4double kineticEnergy = currentKinEnergy; 927 // 873 // 928 // Energy loss correction: 2 version 874 // Energy loss correction: 2 version 929 G4double eloss = 0.0; 875 G4double eloss = 0.0; 930 // if (fTheTrueStepLenght > currentRange*dtrl 876 // if (fTheTrueStepLenght > currentRange*dtrl) { 931 eloss = kineticEnergy - GetEnergy(particle,c 877 eloss = kineticEnergy - GetEnergy(particle,currentRange-fTheTrueStepLenght,currentCouple); 932 // } else { 878 // } else { 933 // eloss = fTheTrueStepLenght*GetDEDX(parti 879 // eloss = fTheTrueStepLenght*GetDEDX(particle,kineticEnergy,currentCouple); 934 // } 880 // } 935 881 936 G4double tau = 0.;// = kineticEnergy/ele 882 G4double tau = 0.;// = kineticEnergy/electron_mass_c2; // where kinEnergy is the mean kinetic energy 937 G4double tau2 = 0.;// = tau*tau; 883 G4double tau2 = 0.;// = tau*tau; 938 G4double eps0 = 0.;// = eloss/kineticEnerg 884 G4double eps0 = 0.;// = eloss/kineticEnergy0; // energy loss fraction to the begin step energy 939 G4double epsm = 0.;// = eloss/kineticEnerg 885 G4double epsm = 0.;// = eloss/kineticEnergy; // energy loss fraction to the mean step energy 940 886 941 // - init. 887 // - init. 942 G4double efEnergy = kineticEnergy; 888 G4double efEnergy = kineticEnergy; 943 G4double efStep = fTheTrueStepLenght; 889 G4double efStep = fTheTrueStepLenght; 944 890 945 G4double kineticEnergy0 = kineticEnergy; 891 G4double kineticEnergy0 = kineticEnergy; 946 if (gIsUseAccurate) { // - use accurate e 892 if (gIsUseAccurate) { // - use accurate energy loss correction 947 kineticEnergy -= 0.5*eloss; // mean ener 893 kineticEnergy -= 0.5*eloss; // mean energy along the full step 948 // other parameters for energy loss correc 894 // other parameters for energy loss corrections 949 tau = kineticEnergy/electron_m 895 tau = kineticEnergy/electron_mass_c2; // where kinEnergy is the mean kinetic energy 950 tau2 = tau*tau; 896 tau2 = tau*tau; 951 eps0 = eloss/kineticEnergy0; // 897 eps0 = eloss/kineticEnergy0; // energy loss fraction to the begin step energy 952 epsm = eloss/kineticEnergy; // 898 epsm = eloss/kineticEnergy; // energy loss fraction to the mean step energy 953 899 954 efEnergy = kineticEnergy * (1.-epsm 900 efEnergy = kineticEnergy * (1.-epsm*epsm*(6.+10.*tau+5.*tau2)/(24.*tau2+48.*tau+72.)); 955 G4double dum = 0.166666*(4.+tau*(6.+tau 901 G4double dum = 0.166666*(4.+tau*(6.+tau*(7.+tau*(4.+tau))))*(epsm/((tau+1.)*(tau+2.)))*(epsm/((tau+1.)*(tau+2.))); 956 efStep = fTheTrueStepLenght*(1.-d 902 efStep = fTheTrueStepLenght*(1.-dum); 957 } else { // - t 903 } else { // - take only mean energy 958 kineticEnergy -= 0.5*eloss; // mean ener 904 kineticEnergy -= 0.5*eloss; // mean energy along the full step 959 efEnergy = kineticEnergy; 905 efEnergy = kineticEnergy; 960 G4double factor = 1./(1.+0.9784671*kinetic 906 G4double factor = 1./(1.+0.9784671*kineticEnergy); //0.9784671 = 1/(2*m_e) 961 eps0 = eloss/kineticEnergy0; 907 eps0 = eloss/kineticEnergy0; 962 epsm = eps0/(1.-0.5*eps0); 908 epsm = eps0/(1.-0.5*eps0); 963 G4double temp = 0.3*(1 -factor*(1.-0.333 909 G4double temp = 0.3*(1 -factor*(1.-0.333333*factor))*eps0*eps0; 964 efStep = fTheTrueStepLenght*(1.+t 910 efStep = fTheTrueStepLenght*(1.+temp); 965 } 911 } 966 // 912 // 967 // compute elastic mfp, first transport mfp, 913 // compute elastic mfp, first transport mfp, screening parameter, and G1 (with Mott-correction 968 // if it was requested by the user) 914 // if it was requested by the user) 969 fLambda1 = GetTransportMeanFreePath(particle 915 fLambda1 = GetTransportMeanFreePath(particle, efEnergy); 970 // s/lambda_el 916 // s/lambda_el 971 G4double lambdan=0.; 917 G4double lambdan=0.; 972 if (fLambda0>0.0) { 918 if (fLambda0>0.0) { 973 lambdan=efStep/fLambda0; 919 lambdan=efStep/fLambda0; 974 } 920 } 975 if (lambdan<=1.0e-12) { 921 if (lambdan<=1.0e-12) { 976 if (fIsEverythingWasDone) { 922 if (fIsEverythingWasDone) { 977 fTheZPathLenght = fTheTrueStepLenght; 923 fTheZPathLenght = fTheTrueStepLenght; 978 } 924 } 979 fIsNoScatteringInMSC = true; 925 fIsNoScatteringInMSC = true; 980 return; 926 return; 981 } 927 } 982 // first moment: 2.* lambdan *scrA*((1.+scrA 928 // first moment: 2.* lambdan *scrA*((1.+scrA)*log(1.+1./scrA)-1.); 983 G4double Qn1 = lambdan *fG1; 929 G4double Qn1 = lambdan *fG1; 984 // sample scattering angles 930 // sample scattering angles 985 // new direction, relative to the orriginal 931 // new direction, relative to the orriginal one is in {uss,vss,wss} 986 G4double cosTheta1 = 1.0, sinTheta1 = 0.0, c 932 G4double cosTheta1 = 1.0, sinTheta1 = 0.0, cosTheta2 = 1.0, sinTheta2 = 0.0; 987 G4double cosPhi1 = 1.0, sinPhi1 = 0.0, c 933 G4double cosPhi1 = 1.0, sinPhi1 = 0.0, cosPhi2 = 1.0, sinPhi2 = 0.0; 988 G4double uss = 0.0, vss = 0.0, w 934 G4double uss = 0.0, vss = 0.0, wss = 1.0; 989 G4double x_coord = 0.0, y_coord = 0.0, z 935 G4double x_coord = 0.0, y_coord = 0.0, z_coord = 1.0; 990 G4double u2 = 0.0, v2 = 0.0; 936 G4double u2 = 0.0, v2 = 0.0; 991 // if we are above the upper grid limit with 937 // if we are above the upper grid limit with lambdaxG1=true-length/first-trans-mfp 992 // => izotropic distribution: lambG1_max =7. 938 // => izotropic distribution: lambG1_max =7.992 but set it to 7 993 if (0.5*Qn1 > 7.0){ 939 if (0.5*Qn1 > 7.0){ 994 cosTheta1 = 1.-2.*G4UniformRand(); 940 cosTheta1 = 1.-2.*G4UniformRand(); 995 sinTheta1 = std::sqrt((1.-cosTheta1)*(1.+c 941 sinTheta1 = std::sqrt((1.-cosTheta1)*(1.+cosTheta1)); 996 cosTheta2 = 1.-2.*G4UniformRand(); 942 cosTheta2 = 1.-2.*G4UniformRand(); 997 sinTheta2 = std::sqrt((1.-cosTheta2)*(1.+c 943 sinTheta2 = std::sqrt((1.-cosTheta2)*(1.+cosTheta2)); 998 } else { 944 } else { 999 // sample 2 scattering cost1, sint1, cost 945 // sample 2 scattering cost1, sint1, cost2 and sint2 for half path 1000 G4double lekin = G4Log(efEnergy); 946 G4double lekin = G4Log(efEnergy); 1001 G4double pt2 = efEnergy*(efEnergy+2.0 947 G4double pt2 = efEnergy*(efEnergy+2.0*CLHEP::electron_mass_c2); 1002 G4double beta2 = pt2/(pt2+CLHEP::electr 948 G4double beta2 = pt2/(pt2+CLHEP::electron_mass_c2*CLHEP::electron_mass_c2); 1003 // backup GS angular dtr pointer (kineti 949 // backup GS angular dtr pointer (kinetic energy and delta index in case of Mott-correction) 1004 // if the first was an msc sampling (the 950 // if the first was an msc sampling (the same will be used if the second is also an msc step) 1005 G4GoudsmitSaundersonTable::GSMSCAngularD 951 G4GoudsmitSaundersonTable::GSMSCAngularDtr *gsDtr = nullptr; 1006 G4int mcEkinIdx = -1; 952 G4int mcEkinIdx = -1; 1007 G4int mcDeltIdx = -1; 953 G4int mcDeltIdx = -1; 1008 G4double transfPar = 0.; 954 G4double transfPar = 0.; 1009 G4bool isMsc = fGSTable->Sampling(0.5*la 955 G4bool isMsc = fGSTable->Sampling(0.5*lambdan, 0.5*Qn1, fScrA, cosTheta1, sinTheta1, lekin, beta2, 1010 curren 956 currentMaterialIndex, &gsDtr, mcEkinIdx, mcDeltIdx, transfPar, 1011 true); 957 true); 1012 fGSTable->Sampling(0.5*lambdan, 0.5*Qn1, 958 fGSTable->Sampling(0.5*lambdan, 0.5*Qn1, fScrA, cosTheta2, sinTheta2, lekin, beta2, 1013 currentMaterialIndex, 959 currentMaterialIndex, &gsDtr, mcEkinIdx, mcDeltIdx, transfPar, !isMsc); 1014 if (cosTheta1+cosTheta2==2.) { // no sca 960 if (cosTheta1+cosTheta2==2.) { // no scattering happened 1015 if (fIsEverythingWasDone) 961 if (fIsEverythingWasDone) 1016 fTheZPathLenght = fTheTrueStepLeng 962 fTheZPathLenght = fTheTrueStepLenght; 1017 fIsNoScatteringInMSC = true; 963 fIsNoScatteringInMSC = true; 1018 return; 964 return; 1019 } 965 } 1020 } 966 } 1021 // sample 2 azimuthal angles 967 // sample 2 azimuthal angles 1022 G4double phi1 = CLHEP::twopi*G4UniformRand( 968 G4double phi1 = CLHEP::twopi*G4UniformRand(); 1023 sinPhi1 = std::sin(phi1); 969 sinPhi1 = std::sin(phi1); 1024 cosPhi1 = std::cos(phi1); 970 cosPhi1 = std::cos(phi1); 1025 G4double phi2 = CLHEP::twopi*G4UniformRand( 971 G4double phi2 = CLHEP::twopi*G4UniformRand(); 1026 sinPhi2 = std::sin(phi2); 972 sinPhi2 = std::sin(phi2); 1027 cosPhi2 = std::cos(phi2); 973 cosPhi2 = std::cos(phi2); 1028 974 1029 // compute final direction realtive to z-di 975 // compute final direction realtive to z-dir 1030 u2 = sinTheta2*cosPhi2; 976 u2 = sinTheta2*cosPhi2; 1031 v2 = sinTheta2*sinPhi2; 977 v2 = sinTheta2*sinPhi2; 1032 G4double u2p = cosTheta1*u2 + sinTheta1*cos 978 G4double u2p = cosTheta1*u2 + sinTheta1*cosTheta2; 1033 uss = u2p*cosPhi1 - v2*sinPhi1; 979 uss = u2p*cosPhi1 - v2*sinPhi1; 1034 vss = u2p*sinPhi1 + v2*cosPhi1; 980 vss = u2p*sinPhi1 + v2*cosPhi1; 1035 wss = cosTheta1*cosTheta2 - sinTheta1*u2; 981 wss = cosTheta1*cosTheta2 - sinTheta1*u2; 1036 982 1037 // set new direction (is scattering frame) 983 // set new direction (is scattering frame) 1038 fTheNewDirection.set(uss,vss,wss); 984 fTheNewDirection.set(uss,vss,wss); 1039 985 1040 // set the fTheZPathLenght if we don't samp 986 // set the fTheZPathLenght if we don't sample displacement and 1041 // we should do everything at the step-limi 987 // we should do everything at the step-limit-phase before we return 1042 if(fIsNoDisplace && fIsEverythingWasDone) 988 if(fIsNoDisplace && fIsEverythingWasDone) 1043 fTheZPathLenght = fTheTrueStepLenght; 989 fTheZPathLenght = fTheTrueStepLenght; 1044 990 1045 // in optimized-mode if the current-safety 991 // in optimized-mode if the current-safety > current-range we do not use dispalcement 1046 if(fIsNoDisplace) 992 if(fIsNoDisplace) 1047 return; 993 return; 1048 994 1049 /////////////////////////////////////////// 995 ////////////////////////////////////////////////////////////////////// 1050 // Compute final position 996 // Compute final position 1051 Qn1 *= fMCtoQ1; 997 Qn1 *= fMCtoQ1; 1052 if (gIsUseAccurate) { 998 if (gIsUseAccurate) { 1053 // correction parameter 999 // correction parameter 1054 G4double par =1.; 1000 G4double par =1.; 1055 if(Qn1<0.7) par = 1.; 1001 if(Qn1<0.7) par = 1.; 1056 else if (Qn1<7.0) par = -0.031376*Qn1+1. 1002 else if (Qn1<7.0) par = -0.031376*Qn1+1.01356; 1057 else par = 0.79; 1003 else par = 0.79; 1058 1004 1059 // Moments with energy loss correction 1005 // Moments with energy loss correction 1060 // --first the uncorrected (for energy l 1006 // --first the uncorrected (for energy loss) values of gamma, eta, a1=a2=0.5*(1-eta), delta 1061 // gamma = G_2/G_1 based on G2 computed 1007 // gamma = G_2/G_1 based on G2 computed from A by using the Wentzel DCS form of G2 1062 G4double loga = G4Log(1.0+1.0/fScrA); 1008 G4double loga = G4Log(1.0+1.0/fScrA); 1063 G4double gamma = 6.0*fScrA*(1.0 + fScrA 1009 G4double gamma = 6.0*fScrA*(1.0 + fScrA)*(loga*(1.0 + 2.0*fScrA) - 2.0)/fG1; 1064 gamma *= fMCtoG2PerG1; 1010 gamma *= fMCtoG2PerG1; 1065 // sample eta from p(eta)=2*eta i.e. P(e 1011 // sample eta from p(eta)=2*eta i.e. P(eta) = eta_square ;-> P(eta) = rand --> eta = sqrt(rand) 1066 G4double eta = std::sqrt(G4UniformRan 1012 G4double eta = std::sqrt(G4UniformRand()); 1067 G4double eta1 = 0.5*(1 - eta); // use 1013 G4double eta1 = 0.5*(1 - eta); // used more than once 1068 // 0.5 +sqrt(6)/6 = 0.9082483; 1014 // 0.5 +sqrt(6)/6 = 0.9082483; 1069 // 1/(4*sqrt(6)) = 0.1020621; 1015 // 1/(4*sqrt(6)) = 0.1020621; 1070 // (4-sqrt(6)/(24*sqrt(6))) = 0.02637471 1016 // (4-sqrt(6)/(24*sqrt(6))) = 0.026374715 1071 // delta = 0.9082483-(0.1020621-0.026374 1017 // delta = 0.9082483-(0.1020621-0.0263747*gamma)*Qn1 without energy loss cor. 1072 G4double delta = 0.9082483-(0.1020621-0 1018 G4double delta = 0.9082483-(0.1020621-0.0263747*gamma)*Qn1; 1073 1019 1074 // compute alpha1 and alpha2 for energy 1020 // compute alpha1 and alpha2 for energy loss correction 1075 G4double temp1 = 2.0 + tau; 1021 G4double temp1 = 2.0 + tau; 1076 G4double temp = (2.0+tau*temp1)/((tau+1 1022 G4double temp = (2.0+tau*temp1)/((tau+1.0)*temp1); 1077 //Take logarithmic dependence 1023 //Take logarithmic dependence 1078 temp = temp - (tau+1.0)/((tau+2.0)*(loga 1024 temp = temp - (tau+1.0)/((tau+2.0)*(loga*(1.0+fScrA)-1.0)); 1079 temp = temp * epsm; 1025 temp = temp * epsm; 1080 temp1 = 1.0 - temp; 1026 temp1 = 1.0 - temp; 1081 delta = delta + 0.40824829*(eps0*(tau+1. 1027 delta = delta + 0.40824829*(eps0*(tau+1.0)/((tau+2.0)* 1082 (loga*(1.0+fScrA)-1.0)*(loga*(1. 1028 (loga*(1.0+fScrA)-1.0)*(loga*(1.0+2.0*fScrA)-2.0)) - 0.25*temp*temp); 1083 G4double b = eta*delta; 1029 G4double b = eta*delta; 1084 G4double c = eta*(1.0-delta); 1030 G4double c = eta*(1.0-delta); 1085 1031 1086 //Calculate transport direction cosines: 1032 //Calculate transport direction cosines: 1087 // ut,vt,wt is the final position divide 1033 // ut,vt,wt is the final position divided by the true step length 1088 G4double w1v2 = cosTheta1*v2; 1034 G4double w1v2 = cosTheta1*v2; 1089 G4double ut = b*sinTheta1*cosPhi1 + c* 1035 G4double ut = b*sinTheta1*cosPhi1 + c*(cosPhi1*u2 - sinPhi1*w1v2) + eta1*uss*temp1; 1090 G4double vt = b*sinTheta1*sinPhi1 + c* 1036 G4double vt = b*sinTheta1*sinPhi1 + c*(sinPhi1*u2 + cosPhi1*w1v2) + eta1*vss*temp1; 1091 G4double wt = eta1*(1+temp) + b* 1037 G4double wt = eta1*(1+temp) + b*cosTheta1 + c*cosTheta2 + eta1*wss*temp1; 1092 1038 1093 // long step correction 1039 // long step correction 1094 ut *=par; 1040 ut *=par; 1095 vt *=par; 1041 vt *=par; 1096 wt *=par; 1042 wt *=par; 1097 1043 1098 // final position relative to the pre-st 1044 // final position relative to the pre-step point in the scattering frame 1099 // ut = x_f/s so needs to multiply by s 1045 // ut = x_f/s so needs to multiply by s 1100 x_coord = ut*fTheTrueStepLenght; 1046 x_coord = ut*fTheTrueStepLenght; 1101 y_coord = vt*fTheTrueStepLenght; 1047 y_coord = vt*fTheTrueStepLenght; 1102 z_coord = wt*fTheTrueStepLenght; 1048 z_coord = wt*fTheTrueStepLenght; 1103 1049 1104 if(fIsEverythingWasDone){ 1050 if(fIsEverythingWasDone){ 1105 // We sample in the step limit so set 1051 // We sample in the step limit so set fTheZPathLenght = transportDistance 1106 // and lateral displacement (x_coord,y 1052 // and lateral displacement (x_coord,y_coord,z_coord-transportDistance) 1107 //Calculate transport distance 1053 //Calculate transport distance 1108 G4double transportDistance = std::sqr 1054 G4double transportDistance = std::sqrt(x_coord*x_coord+y_coord*y_coord+z_coord*z_coord); 1109 // protection 1055 // protection 1110 if(transportDistance>fTheTrueStepLengh 1056 if(transportDistance>fTheTrueStepLenght) 1111 transportDistance = fTheTrueStepLen 1057 transportDistance = fTheTrueStepLenght; 1112 fTheZPathLenght = transportDistance; 1058 fTheZPathLenght = transportDistance; 1113 } 1059 } 1114 // else:: we sample in the DoIt so 1060 // else:: we sample in the DoIt so 1115 // the fTheZPathLenght was already 1061 // the fTheZPathLenght was already set and was taken as transport along zet 1116 fTheDisplacementVector.set(x_coord,y_coo 1062 fTheDisplacementVector.set(x_coord,y_coord,z_coord-fTheZPathLenght); 1117 } else { 1063 } else { 1118 // compute zz = <z>/tPathLength 1064 // compute zz = <z>/tPathLength 1119 // s -> true-path-length 1065 // s -> true-path-length 1120 // z -> geom-path-length:: when PRESTA i 1066 // z -> geom-path-length:: when PRESTA is used z =(def.) <z> 1121 // r -> lateral displacement = s/2 sin(t 1067 // r -> lateral displacement = s/2 sin(theta) => x_f = r cos(phi); y_f = r sin(phi) 1122 G4double zz = 0.0; 1068 G4double zz = 0.0; 1123 if(fIsEverythingWasDone){ 1069 if(fIsEverythingWasDone){ 1124 // We sample in the step limit so set 1070 // We sample in the step limit so set fTheZPathLenght = transportDistance 1125 // and lateral displacement (x_coord, 1071 // and lateral displacement (x_coord,y_coord,z_coord-transportDistance) 1126 if(Qn1<0.1) { // use 3-order Taylor a 1072 if(Qn1<0.1) { // use 3-order Taylor approximation of (1-exp(-x))/x around x=0 1127 zz = 1.0 - Qn1*(0.5 - Qn1*(0.166666 1073 zz = 1.0 - Qn1*(0.5 - Qn1*(0.166666667 - 0.041666667*Qn1)); // 1/6 =0.166..7 ; 1/24=0.041.. 1128 } else { 1074 } else { 1129 zz = (1.-G4Exp(-Qn1))/Qn1; 1075 zz = (1.-G4Exp(-Qn1))/Qn1; 1130 } 1076 } 1131 } else { 1077 } else { 1132 // we sample in the DoIt so 1078 // we sample in the DoIt so 1133 // the fTheZPathLenght was already se 1079 // the fTheZPathLenght was already set and was taken as transport along zet 1134 zz = fTheZPathLenght/fTheTrueStepLeng 1080 zz = fTheZPathLenght/fTheTrueStepLenght; 1135 } 1081 } 1136 1082 1137 G4double rr = (1.-zz*zz)/(1.-wss*wss); / 1083 G4double rr = (1.-zz*zz)/(1.-wss*wss); // s^2 >= <z>^2+r^2 :: where r^2 = s^2/4 sin^2(theta) 1138 if(rr >= 0.25) rr = 0.25; // 1084 if(rr >= 0.25) rr = 0.25; // (1-<z>^2/s^2)/sin^2(theta) >= r^2/(s^2 sin^2(theta)) = 1/4 must hold 1139 G4double rperp = fTheTrueStepLenght*std: 1085 G4double rperp = fTheTrueStepLenght*std::sqrt(rr); // this is r/sint 1140 x_coord = rperp*uss; 1086 x_coord = rperp*uss; 1141 y_coord = rperp*vss; 1087 y_coord = rperp*vss; 1142 z_coord = zz*fTheTrueStepLenght; 1088 z_coord = zz*fTheTrueStepLenght; 1143 1089 1144 if(fIsEverythingWasDone){ 1090 if(fIsEverythingWasDone){ 1145 G4double transportDistance = std::sqrt 1091 G4double transportDistance = std::sqrt(x_coord*x_coord + y_coord*y_coord + z_coord*z_coord); 1146 fTheZPathLenght = transportDistance; 1092 fTheZPathLenght = transportDistance; 1147 } 1093 } 1148 1094 1149 fTheDisplacementVector.set(x_coord,y_coo 1095 fTheDisplacementVector.set(x_coord,y_coord,z_coord- fTheZPathLenght); 1150 } 1096 } 1151 } 1097 } 1152 1098