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Please see the license in the file << 14 // * use. * 16 // * for the full disclaimer and the limitatio << 17 // * 15 // * * 18 // * This code implementation is the result << 16 // * This code implementation is the intellectual property of the * 19 // * technical work of the GEANT4 collaboratio << 17 // * GEANT4 collaboration. * 20 // * By using, copying, modifying or distri << 18 // * By copying, distributing or modifying the Program (or any work * 21 // * any work based on the software) you ag << 19 // * based on the Program) you indicate your acceptance of this * 22 // * use in resulting scientific publicati << 20 // * statement, and all its terms. * 23 // * acceptance of all terms of the Geant4 Sof << 24 // ******************************************* 21 // ******************************************************************** 25 // 22 // 26 // G4Mag_SpinEqRhs implementation << 27 // 23 // 28 // Created: J.Apostolakis, P.Gumplinger - 08.0 << 24 // $Id: G4Mag_SpinEqRhs.cc,v 1.11 2004/12/02 09:55:20 gcosmo Exp $ >> 25 // GEANT4 tag $Name: geant4-08-00-patch-01 $ >> 26 // >> 27 // This is the standard right-hand side for equation of motion. >> 28 // This version of the right-hand side includes the three components >> 29 // of the particle's spin. >> 30 // >> 31 // J. Apostolakis, February 8th, 1999 >> 32 // P. Gumplinger, February 8th, 1999 >> 33 // D. Cote-Ahern, P. Gumplinger, April 11th, 2001 >> 34 // 29 // ------------------------------------------- 35 // -------------------------------------------------------------------- 30 36 31 #include "G4Mag_SpinEqRhs.hh" 37 #include "G4Mag_SpinEqRhs.hh" 32 #include "G4PhysicalConstants.hh" << 33 #include "G4SystemOfUnits.hh" << 34 #include "G4MagneticField.hh" 38 #include "G4MagneticField.hh" 35 #include "G4ThreeVector.hh" 39 #include "G4ThreeVector.hh" 36 40 37 G4Mag_SpinEqRhs::G4Mag_SpinEqRhs( G4MagneticFi 41 G4Mag_SpinEqRhs::G4Mag_SpinEqRhs( G4MagneticField* MagField ) 38 : G4Mag_EqRhs( MagField ) << 42 : G4Mag_EqRhs( MagField ) 39 { 43 { >> 44 anomaly = 1.165923e-3; 40 } 45 } 41 46 42 G4Mag_SpinEqRhs::~G4Mag_SpinEqRhs() = default; << 47 G4Mag_SpinEqRhs::~G4Mag_SpinEqRhs() {} 43 48 44 void 49 void 45 G4Mag_SpinEqRhs::SetChargeMomentumMass(G4Charg << 50 G4Mag_SpinEqRhs::SetChargeMomentumMass(G4double particleCharge, // in e+ units 46 G4doubl 51 G4double MomentumXc, 47 G4doubl << 52 G4double mass) 48 { 53 { 49 G4Mag_EqRhs::SetChargeMomentumMass( particl << 54 // To set fCof_val >> 55 G4Mag_EqRhs::SetChargeMomentumMass(particleCharge, MomentumXc, mass); 50 56 51 charge = particleCharge.GetCharge(); << 57 omegac = 0.105658387*GeV/mass * 2.837374841e-3*(rad/cm/kilogauss); 52 mass = particleMass; << 53 magMoment = particleCharge.GetMagneticDipol << 54 spin = particleCharge.GetSpin(); << 55 << 56 omegac = (eplus/mass)*c_light; << 57 << 58 G4double muB = 0.5*eplus*hbar_Planck/(mass/ << 59 << 60 G4double g_BMT; << 61 if ( spin != 0. ) << 62 { << 63 g_BMT = (std::abs(magMoment)/muB)/spin; << 64 } << 65 else << 66 { << 67 g_BMT = 2.; << 68 } << 69 58 70 anomaly = (g_BMT - 2.)/2.; << 59 ParticleCharge = particleCharge; 71 60 72 G4double E = std::sqrt(sqr(MomentumXc)+sqr( << 61 E = std::sqrt(sqr(MomentumXc)+sqr(mass)); 73 beta = MomentumXc/E; 62 beta = MomentumXc/E; 74 gamma = E/mass; 63 gamma = E/mass; >> 64 75 } 65 } 76 66 77 void 67 void 78 G4Mag_SpinEqRhs::EvaluateRhsGivenB( const G4do 68 G4Mag_SpinEqRhs::EvaluateRhsGivenB( const G4double y[], 79 const G4do << 69 const G4double B[3], 80 G4do << 70 G4double dydx[] ) const 81 { 71 { 82 G4double momentum_mag_square = sqr(y[3]) + 72 G4double momentum_mag_square = sqr(y[3]) + sqr(y[4]) + sqr(y[5]); 83 G4double inv_momentum_magnitude = 1.0 / std 73 G4double inv_momentum_magnitude = 1.0 / std::sqrt( momentum_mag_square ); 84 G4double cof = FCof()*inv_momentum_magnitud 74 G4double cof = FCof()*inv_momentum_magnitude; 85 75 86 dydx[0] = y[3] * inv_momentum_magnitude; 76 dydx[0] = y[3] * inv_momentum_magnitude; // (d/ds)x = Vx/V 87 dydx[1] = y[4] * inv_momentum_magnitude; 77 dydx[1] = y[4] * inv_momentum_magnitude; // (d/ds)y = Vy/V 88 dydx[2] = y[5] * inv_momentum_magnitude; 78 dydx[2] = y[5] * inv_momentum_magnitude; // (d/ds)z = Vz/V 89 << 79 dydx[3] = cof*(y[4]*B[2] - y[5]*B[1]) ; // Ax = a*(Vy*Bz - Vz*By) 90 if (charge == 0.) << 80 dydx[4] = cof*(y[5]*B[0] - y[3]*B[2]) ; // Ay = a*(Vz*Bx - Vx*Bz) 91 { << 81 dydx[5] = cof*(y[3]*B[1] - y[4]*B[0]) ; // Az = a*(Vx*By - Vy*Bx) 92 dydx[3] = 0.; << 93 dydx[4] = 0.; << 94 dydx[5] = 0.; << 95 } << 96 else << 97 { << 98 dydx[3] = cof*(y[4]*B[2] - y[5]*B[1]) ; << 99 dydx[4] = cof*(y[5]*B[0] - y[3]*B[2]) ; << 100 dydx[5] = cof*(y[3]*B[1] - y[4]*B[0]) ; << 101 } << 102 82 103 G4ThreeVector u(y[3], y[4], y[5]); 83 G4ThreeVector u(y[3], y[4], y[5]); 104 u *= inv_momentum_magnitude; 84 u *= inv_momentum_magnitude; 105 85 106 G4ThreeVector BField(B[0],B[1],B[2]); 86 G4ThreeVector BField(B[0],B[1],B[2]); 107 87 108 G4double udb = anomaly*beta*gamma/(1.+gamma 88 G4double udb = anomaly*beta*gamma/(1.+gamma) * (BField * u); 109 G4double ucb = (anomaly+1./gamma)/beta; 89 G4double ucb = (anomaly+1./gamma)/beta; 110 90 111 // Initialise the values of dydx that we do 91 // Initialise the values of dydx that we do not update. 112 dydx[6] = dydx[7] = dydx[8] = 0.0; 92 dydx[6] = dydx[7] = dydx[8] = 0.0; 113 93 114 G4ThreeVector Spin(y[9],y[10],y[11]); 94 G4ThreeVector Spin(y[9],y[10],y[11]); >> 95 G4ThreeVector dSpin; 115 96 116 G4double pcharge; << 97 dSpin = ParticleCharge*omegac*(ucb*(Spin.cross(BField))-udb*(Spin.cross(u))); 117 if (charge == 0.) << 118 { << 119 pcharge = 1.; << 120 } << 121 else << 122 { << 123 pcharge = charge; << 124 } << 125 << 126 G4ThreeVector dSpin(0.,0.,0.); << 127 if (Spin.mag2() != 0.) << 128 { << 129 dSpin = pcharge*omegac*(ucb*(Spin.cross(B << 130 } << 131 98 132 dydx[9] = dSpin.x(); << 99 dydx[ 9] = dSpin.x(); 133 dydx[10] = dSpin.y(); 100 dydx[10] = dSpin.y(); 134 dydx[11] = dSpin.z(); 101 dydx[11] = dSpin.z(); 135 102 136 return; << 103 return ; 137 } 104 } 138 105