#include <G4EqEMFieldWithSpin.hh>
Inheritance diagram for G4EqEMFieldWithSpin:
Public Member Functions | |
| G4EqEMFieldWithSpin (G4ElectroMagneticField *emField) | |
| ~G4EqEMFieldWithSpin () | |
| void | SetChargeMomentumMass (G4double particleCharge, G4double MomentumXc, G4double mass) |
| void | EvaluateRhsGivenB (const G4double y[], const G4double Field[], G4double dydx[]) const |
| void | SetAnomaly (G4double a) |
| G4double | GetAnomaly () const |
Definition at line 48 of file G4EqEMFieldWithSpin.hh.
| G4EqEMFieldWithSpin::G4EqEMFieldWithSpin | ( | G4ElectroMagneticField * | emField | ) |
Definition at line 45 of file G4EqEMFieldWithSpin.cc.
00046 : G4EquationOfMotion( emField ), fElectroMagCof(0.), fMassCof(0.), 00047 omegac(0.), anomaly(0.0011659208), pcharge(0.), E(0.), gamma(0.), beta(0.) 00048 { 00049 }
| G4EqEMFieldWithSpin::~G4EqEMFieldWithSpin | ( | ) |
| void G4EqEMFieldWithSpin::EvaluateRhsGivenB | ( | const G4double | y[], | |
| const G4double | Field[], | |||
| G4double | dydx[] | |||
| ) | const |
Definition at line 74 of file G4EqEMFieldWithSpin.cc.
00077 { 00078 00079 // Components of y: 00080 // 0-2 dr/ds, 00081 // 3-5 dp/ds - momentum derivatives 00082 // 9-11 dSpin/ds = (1/beta) dSpin/dt - spin derivatives 00083 00084 // The BMT equation, following J.D.Jackson, Classical 00085 // Electrodynamics, Second Edition, 00086 // dS/dt = (e/mc) S \cross 00087 // [ (g/2-1 +1/\gamma) B 00088 // -(g/2-1)\gamma/(\gamma+1) (\beta \cdot B)\beta 00089 // -(g/2-\gamma/(\gamma+1) \beta \cross E ] 00090 // where 00091 // S = \vec{s}, where S^2 = 1 00092 // B = \vec{B} 00093 // \beta = \vec{\beta} = \beta \vec{u} with u^2 = 1 00094 // E = \vec{E} 00095 00096 G4double pSquared = y[3]*y[3] + y[4]*y[4] + y[5]*y[5] ; 00097 00098 G4double Energy = std::sqrt( pSquared + fMassCof ); 00099 G4double cof2 = Energy/c_light ; 00100 00101 G4double pModuleInverse = 1.0/std::sqrt(pSquared) ; 00102 00103 G4double inverse_velocity = Energy * pModuleInverse / c_light; 00104 00105 G4double cof1 = fElectroMagCof*pModuleInverse ; 00106 00107 dydx[0] = y[3]*pModuleInverse ; 00108 dydx[1] = y[4]*pModuleInverse ; 00109 dydx[2] = y[5]*pModuleInverse ; 00110 00111 dydx[3] = cof1*(cof2*Field[3] + (y[4]*Field[2] - y[5]*Field[1])) ; 00112 00113 dydx[4] = cof1*(cof2*Field[4] + (y[5]*Field[0] - y[3]*Field[2])) ; 00114 00115 dydx[5] = cof1*(cof2*Field[5] + (y[3]*Field[1] - y[4]*Field[0])) ; 00116 00117 dydx[6] = dydx[8] = 0.;//not used 00118 00119 // Lab Time of flight 00120 dydx[7] = inverse_velocity; 00121 00122 G4ThreeVector BField(Field[0],Field[1],Field[2]); 00123 G4ThreeVector EField(Field[3],Field[4],Field[5]); 00124 00125 EField /= c_light; 00126 00127 G4ThreeVector u(y[3], y[4], y[5]); 00128 u *= pModuleInverse; 00129 00130 G4double udb = anomaly*beta*gamma/(1.+gamma) * (BField * u); 00131 G4double ucb = (anomaly+1./gamma)/beta; 00132 G4double uce = anomaly + 1./(gamma+1.); 00133 00134 G4ThreeVector Spin(y[9],y[10],y[11]); 00135 00136 G4ThreeVector dSpin 00137 = pcharge*omegac*( ucb*(Spin.cross(BField))-udb*(Spin.cross(u)) 00138 // from Jackson 00139 // -uce*Spin.cross(u.cross(EField)) ); 00140 // but this form has one less operation 00141 - uce*(u*(Spin*EField) - EField*(Spin*u)) ); 00142 00143 dydx[ 9] = dSpin.x(); 00144 dydx[10] = dSpin.y(); 00145 dydx[11] = dSpin.z(); 00146 00147 return ; 00148 }
| G4double G4EqEMFieldWithSpin::GetAnomaly | ( | ) | const [inline] |
| void G4EqEMFieldWithSpin::SetAnomaly | ( | G4double | a | ) | [inline] |
| void G4EqEMFieldWithSpin::SetChargeMomentumMass | ( | G4double | particleCharge, | |
| G4double | MomentumXc, | |||
| G4double | mass | |||
| ) | [virtual] |
Implements G4EquationOfMotion.
Definition at line 56 of file G4EqEMFieldWithSpin.cc.
References sqr().
00059 { 00060 fElectroMagCof = eplus*particleCharge*c_light ; 00061 fMassCof = particleMass*particleMass ; 00062 00063 omegac = (eplus/particleMass)*c_light; 00064 00065 pcharge = particleCharge; 00066 00067 E = std::sqrt(sqr(MomentumXc)+sqr(particleMass)); 00068 beta = MomentumXc/E; 00069 gamma = E/particleMass; 00070 00071 }
1.4.7