Geant4  10.01
G4MonopoleEq.cc
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27 // $Id: G4MonopoleEq.cc 69699 2013-05-13 08:50:30Z gcosmo $
28 //
29 //
30 // This is the right-hand side for equation of motion for a
31 // magnetic charge in a combined Electro-Magnetic field
32 //
33 // d(p_c)/ds=g{c-energyB_ - p_c x E}/pc
34 //
35 // 17.11.09 V.Grichine
36 //
37 // -------------------------------------------------------------------
38 
39 #include "G4MonopoleEq.hh"
40 #include "globals.hh"
41 #include "G4PhysicalConstants.hh"
42 #include "G4SystemOfUnits.hh"
43 
44 void
46  G4double,
47  G4double particleMass)
48 {
49  G4double pcharge = particleCharge.GetCharge();
50  fElectroMagCof = eplus*pcharge; // no *c_light as for ususal q
51  fElectroMagCof /= 2*fine_structure_const;
52 
53  fMassCof = particleMass*particleMass ;
54 }
55 
56 
57 
58 void
60  const G4double Field[],
61  G4double dydx[] ) const
62 {
63 
64  // Components of y:
65  // 0-2 dr/ds,
66  // 3-5 d(pc)/ds - momentum derivatives
67 
68  G4double pSquared = y[3]*y[3] + y[4]*y[4] + y[5]*y[5] ;
69 
70  G4double Energy = std::sqrt( pSquared + fMassCof );
71  G4double cof2 = Energy*c_light ;
72 
73  G4double pModuleInverse = 1.0/std::sqrt(pSquared) ;
74 
75  // G4double inverse_velocity = Energy * c_light * pModuleInverse;
76  G4double inverse_velocity = Energy * pModuleInverse / c_light;
77 
78  G4double cof1 = fElectroMagCof*pModuleInverse ;
79 
80  // G4double vDotE = y[3]*Field[3] + y[4]*Field[4] + y[5]*Field[5] ;
81 
82  dydx[0] = y[3]*pModuleInverse ;
83  dydx[1] = y[4]*pModuleInverse ;
84  dydx[2] = y[5]*pModuleInverse ;
85 
86  dydx[3] = cof1*(cof2*Field[0] - (y[4]*Field[5] - y[5]*Field[4])) ;
87 
88  dydx[4] = cof1*(cof2*Field[1] - (y[5]*Field[3] - y[3]*Field[5])) ;
89 
90  dydx[5] = cof1*(cof2*Field[2] - (y[3]*Field[4] - y[4]*Field[3])) ;
91 
92  dydx[6] = 0.;//not used
93 
94  // Lab Time of flight
95  dydx[7] = inverse_velocity;
96  return ;
97 }
G4double GetCharge() const
void EvaluateRhsGivenB(const G4double y[], const G4double Field[], G4double dydx[]) const
Definition: G4MonopoleEq.cc:59
G4double fMassCof
Definition: G4MonopoleEq.hh:71
G4double fElectroMagCof
Definition: G4MonopoleEq.hh:70
void SetChargeMomentumMass(G4ChargeState particleCharge, G4double MomentumXc, G4double mass)
Definition: G4MonopoleEq.cc:45
double G4double
Definition: G4Types.hh:76
static const double eplus
Definition: G4SIunits.hh:178