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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 // G4EqEMFieldWithEDM implementation << 26 // >> 27 // $Id: G4EqEMFieldWithEDM.cc,v 1.3 2010-07-14 10:00:36 gcosmo Exp $ >> 28 // GEANT4 tag $Name: not supported by cvs2svn $ >> 29 // 27 // 30 // 28 // This is the standard right-hand side for e 31 // This is the standard right-hand side for equation of motion. 29 // 32 // 30 // Created: Kevin Lynch, 19.02.2009 - Based on << 33 // 19.02.2009 Kevin Lynch, based on G4EqEMFieldWithSpin 31 // Modified: Hiromi Iinuma, 06.11.2009 - see: << 34 // 06.11.2009 Hiromi Iinuma see: 32 // http://hypernews.slac.stanford.edu/HyperN << 35 // http://hypernews.slac.stanford.edu/HyperNews/geant4/get/emfields/161.html >> 36 // 33 // ------------------------------------------- 37 // ------------------------------------------------------------------- 34 38 35 #include "G4EqEMFieldWithEDM.hh" 39 #include "G4EqEMFieldWithEDM.hh" 36 #include "G4ElectroMagneticField.hh" 40 #include "G4ElectroMagneticField.hh" 37 #include "G4ThreeVector.hh" 41 #include "G4ThreeVector.hh" 38 #include "globals.hh" 42 #include "globals.hh" 39 #include "G4PhysicalConstants.hh" << 40 #include "G4SystemOfUnits.hh" << 41 43 42 G4EqEMFieldWithEDM::G4EqEMFieldWithEDM(G4Elect << 44 G4EqEMFieldWithEDM::G4EqEMFieldWithEDM(G4ElectroMagneticField *emField ) 43 : G4EquationOfMotion( emField ) << 45 : G4EquationOfMotion( emField ), fElectroMagCof(0.), fMassCof(0.), >> 46 omegac(0.), anomaly(0.0011659208), eta(0.), pcharge(0.), E(0.), >> 47 gamma(0.), beta(0.) 44 { 48 { 45 } 49 } 46 50 47 G4EqEMFieldWithEDM::~G4EqEMFieldWithEDM() = de << 51 G4EqEMFieldWithEDM::~G4EqEMFieldWithEDM() >> 52 { >> 53 } 48 54 49 void 55 void 50 G4EqEMFieldWithEDM::SetChargeMomentumMass(G4Ch << 56 G4EqEMFieldWithEDM::SetChargeMomentumMass(G4double particleCharge, // e+ units 51 G4do << 57 G4double MomentumXc, 52 G4do << 58 G4double particleMass) 53 { 59 { 54 charge = particleCharge.GetCharge(); << 60 fElectroMagCof = eplus*particleCharge*c_light ; 55 mass = particleMass; << 61 fMassCof = particleMass*particleMass ; 56 magMoment = particleCharge.GetMagneticDipol << 62 57 spin = particleCharge.GetSpin(); << 63 omegac = (eplus/particleMass)*c_light; 58 << 59 fElectroMagCof = eplus*charge*c_light; << 60 fMassCof = mass*mass; << 61 << 62 omegac = (eplus/mass)*c_light; << 63 << 64 G4double muB = 0.5*eplus*hbar_Planck/(mass/ << 65 << 66 G4double g_BMT; << 67 if ( spin != 0. ) << 68 { << 69 g_BMT = (std::abs(magMoment)/muB)/spin; << 70 } << 71 else << 72 { << 73 g_BMT = 2.; << 74 } << 75 64 76 anomaly = (g_BMT - 2.)/2.; << 65 pcharge = particleCharge; 77 66 78 G4double E = std::sqrt(sqr(MomentumXc)+sqr( << 67 E = std::sqrt(sqr(MomentumXc)+sqr(particleMass)); 79 beta = MomentumXc/E; 68 beta = MomentumXc/E; 80 gamma = E/mass; << 69 gamma = E/particleMass; >> 70 81 } 71 } 82 72 83 void 73 void 84 G4EqEMFieldWithEDM::EvaluateRhsGivenB(const G4 74 G4EqEMFieldWithEDM::EvaluateRhsGivenB(const G4double y[], 85 const G4 << 75 const G4double Field[], 86 G4 << 76 G4double dydx[] ) const 87 { 77 { 88 78 89 // Components of y: 79 // Components of y: 90 // 0-2 dr/ds, 80 // 0-2 dr/ds, 91 // 3-5 dp/ds - momentum derivatives 81 // 3-5 dp/ds - momentum derivatives 92 // 9-11 dSpin/ds = (1/beta) dSpin/dt - s 82 // 9-11 dSpin/ds = (1/beta) dSpin/dt - spin derivatives 93 83 94 // The BMT equation, following J.D.Jackson, 84 // The BMT equation, following J.D.Jackson, Classical 95 // Electrodynamics, Second Edition, with ad 85 // Electrodynamics, Second Edition, with additions for EDM 96 // evolution from 86 // evolution from 97 // M.Nowakowski, et.al. Eur.J.Phys.26, pp 5 87 // M.Nowakowski, et.al. Eur.J.Phys.26, pp 545-560, (2005) 98 // or 88 // or 99 // Silenko, Phys.Rev.ST Accel.Beams 9:03400 89 // Silenko, Phys.Rev.ST Accel.Beams 9:034003, (2006) 100 90 101 // dS/dt = (e/m) S \cross 91 // dS/dt = (e/m) S \cross 102 // MDM: [ (g/2-1 +1/\gamma) B 92 // MDM: [ (g/2-1 +1/\gamma) B 103 // -(g/2-1)\gamma/(\gamma+1) 93 // -(g/2-1)\gamma/(\gamma+1) (\beta \cdot B)\beta 104 // -(g/2-\gamma/(\gamma+1) \b 94 // -(g/2-\gamma/(\gamma+1) \beta \cross E 105 // 95 // 106 // EDM: eta/2( E - gamma/(gamma+1) \ 96 // EDM: eta/2( E - gamma/(gamma+1) \beta (\beta \cdot E) 107 // + \beta \cross B ) ] 97 // + \beta \cross B ) ] 108 // 98 // 109 // where 99 // where 110 // S = \vec{s}, where S^2 = 1 100 // S = \vec{s}, where S^2 = 1 111 // B = \vec{B} 101 // B = \vec{B} 112 // \beta = \vec{\beta} = \beta \vec{u} with 102 // \beta = \vec{\beta} = \beta \vec{u} with u^2 = 1 113 // E = \vec{E} 103 // E = \vec{E} 114 104 115 G4double pSquared = y[3]*y[3] + y[4]*y[4] + 105 G4double pSquared = y[3]*y[3] + y[4]*y[4] + y[5]*y[5] ; 116 106 117 G4double Energy = std::sqrt( pSquared + f 107 G4double Energy = std::sqrt( pSquared + fMassCof ); 118 G4double cof2 = Energy/c_light ; 108 G4double cof2 = Energy/c_light ; 119 109 120 G4double pModuleInverse = 1.0/std::sqrt(pS 110 G4double pModuleInverse = 1.0/std::sqrt(pSquared) ; 121 111 122 G4double inverse_velocity = Energy * pModul 112 G4double inverse_velocity = Energy * pModuleInverse / c_light; 123 113 124 G4double cof1 = fElectroMagCof*pModuleI 114 G4double cof1 = fElectroMagCof*pModuleInverse ; 125 115 126 dydx[0] = y[3]*pModuleInverse ; 116 dydx[0] = y[3]*pModuleInverse ; 127 dydx[1] = y[4]*pModuleInverse ; 117 dydx[1] = y[4]*pModuleInverse ; 128 dydx[2] = y[5]*pModuleInverse ; 118 dydx[2] = y[5]*pModuleInverse ; 129 119 130 dydx[3] = cof1*(cof2*Field[3] + (y[4]*Field 120 dydx[3] = cof1*(cof2*Field[3] + (y[4]*Field[2] - y[5]*Field[1])) ; 131 121 132 dydx[4] = cof1*(cof2*Field[4] + (y[5]*Field 122 dydx[4] = cof1*(cof2*Field[4] + (y[5]*Field[0] - y[3]*Field[2])) ; 133 123 134 dydx[5] = cof1*(cof2*Field[5] + (y[3]*Field 124 dydx[5] = cof1*(cof2*Field[5] + (y[3]*Field[1] - y[4]*Field[0])) ; 135 125 136 dydx[6] = dydx[8] = 0.;//not used 126 dydx[6] = dydx[8] = 0.;//not used 137 127 138 // Lab Time of flight 128 // Lab Time of flight 139 dydx[7] = inverse_velocity; 129 dydx[7] = inverse_velocity; 140 130 141 G4ThreeVector BField(Field[0],Field[1],Fiel 131 G4ThreeVector BField(Field[0],Field[1],Field[2]); 142 G4ThreeVector EField(Field[3],Field[4],Fiel 132 G4ThreeVector EField(Field[3],Field[4],Field[5]); 143 133 144 EField /= c_light; 134 EField /= c_light; 145 135 146 G4ThreeVector u(y[3], y[4], y[5]); 136 G4ThreeVector u(y[3], y[4], y[5]); 147 u *= pModuleInverse; 137 u *= pModuleInverse; 148 138 149 G4double udb = anomaly*beta*gamma/(1.+gamma 139 G4double udb = anomaly*beta*gamma/(1.+gamma) * (BField * u); 150 G4double ucb = (anomaly+1./gamma)/beta; 140 G4double ucb = (anomaly+1./gamma)/beta; 151 G4double uce = anomaly + 1./(gamma+1.); 141 G4double uce = anomaly + 1./(gamma+1.); 152 G4double ude = beta*gamma/(1.+gamma)*(EFiel 142 G4double ude = beta*gamma/(1.+gamma)*(EField*u); 153 143 154 G4ThreeVector Spin(y[9],y[10],y[11]); 144 G4ThreeVector Spin(y[9],y[10],y[11]); 155 145 156 G4double pcharge; << 146 G4ThreeVector dSpin 157 if (charge == 0.) << 147 = pcharge*omegac*( ucb*(Spin.cross(BField))-udb*(Spin.cross(u)) 158 { << 148 // from Jackson 159 pcharge = 1.; << 149 // -uce*Spin.cross(u.cross(EField)) ) 160 } << 150 // but this form has one less operation 161 else << 151 - uce*(u*(Spin*EField) - EField*(Spin*u)) 162 { << 152 + eta/2.*(Spin.cross(EField) - ude*(Spin.cross(u)) 163 pcharge = charge; << 153 // +Spin.cross(u.cross(Bfield)) 164 } << 154 + (u*(Spin*BField) - BField*(Spin*u)) ) ); 165 << 166 G4ThreeVector dSpin(0.,0.,0.); << 167 if (Spin.mag2() != 0.) << 168 { << 169 dSpin = pcharge*omegac*( ucb*(Spin.cross << 170 // from Jacks << 171 // -uce*Spin. << 172 // but this f << 173 - uce*(u*(Spin*EField << 174 + eta/2.*(Spin.cross( << 175 // +Spin.cros << 176 + (u*(Spin*BField) - << 177 } << 178 155 179 dydx[ 9] = dSpin.x(); 156 dydx[ 9] = dSpin.x(); 180 dydx[10] = dSpin.y(); 157 dydx[10] = dSpin.y(); 181 dydx[11] = dSpin.z(); 158 dydx[11] = dSpin.z(); 182 159 183 return; << 160 return ; 184 } 161 } 185 162