| Geant4 Cross Reference |
1 // 1 //
2 // ******************************************* << 2 // This is the standard right-hand side for equation of motion.
3 // * License and Disclaimer <<
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17 // * <<
18 // * This code implementation is the result <<
19 // * technical work of the GEANT4 collaboratio <<
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21 // * any work based on the software) you ag <<
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24 // ******************************************* <<
25 // 3 //
26 // G4EqMagElectricField implementation << 4 // The only case another is required is when using a moving reference
>> 5 // frame ... or extending the class to include additional Forces,
>> 6 // eg an electric field
27 // 7 //
28 // This is the standard right-hand side for eq << 8 // 10.11.98 V.Grichine
29 // 9 //
30 // The only case another is required is when u <<
31 // frame ... or extending the class to include <<
32 // e.g., an electric field <<
33 // <<
34 // Created: V.Grichine, 10.11.1998 <<
35 // ------------------------------------------- <<
36 <<
37 #include "G4EqMagElectricField.hh" 10 #include "G4EqMagElectricField.hh"
38 #include "globals.hh" <<
39 #include "G4PhysicalConstants.hh" <<
40 #include "G4SystemOfUnits.hh" <<
41 <<
42 G4EqMagElectricField::G4EqMagElectricField(G4E <<
43 : G4EquationOfMotion( emField ) <<
44 { <<
45 } <<
46 <<
47 G4EqMagElectricField::~G4EqMagElectricField() <<
48 11
49 void 12 void
50 G4EqMagElectricField::SetChargeMomentumMass(G4 << 13 G4EqMagElectricField::SetChargeMomentumMass(G4double particleCharge, // e+ units
51 G4 << 14 G4double MomentumXc,
52 G4 15 G4double particleMass)
53 { 16 {
54 G4double pcharge = particleCharge.GetCharge << 17 fElectroMagCof = eplus*c_squared ;
55 fElectroMagCof = eplus*pcharge*c_light ; << 18 fElectroMagCof *= particleCharge/particleMass;
56 fMassCof = particleMass*particleMass ; <<
57 } 19 }
58 20
>> 21
>> 22
59 void 23 void
60 G4EqMagElectricField::EvaluateRhsGivenB(const 24 G4EqMagElectricField::EvaluateRhsGivenB(const G4double y[],
61 const << 25 const G4double Field[],
62 << 26 G4double dydx[] ) const
63 { 27 {
>> 28
64 // Components of y: 29 // Components of y:
65 // 0-2 dr/ds, 30 // 0-2 dr/ds,
66 // 3-5 dp/ds - momentum derivatives << 31 // 3-5 dv/ds
67 << 32 // FCof() = charge/mass
68 G4double pSquared = y[3]*y[3] + y[4]*y[4] + <<
69 33
70 G4double Energy = std::sqrt( pSquared + f << 34 G4double vSquared = y[3]*y[3] + y[4]*y[4] + y[5]*y[5] ;
71 G4double cof2 = Energy/c_light ; <<
72 35
73 G4double pModuleInverse = 1.0/std::sqrt(pS << 36 G4double vModule = sqrt(vSquared) ;
74 37
75 G4double inverse_velocity = Energy * pModul << 38 G4double vDotE = y[3]*Field[3] + y[4]*Field[4] + y[5]*Field[5] ;
76 39
77 G4double cof1 = fElectroMagCof*pModuleI << 40 G4double gammaReci = sqrt(1 - vSquared/c_squared) ;
78 41
79 dydx[0] = y[3]*pModuleInverse ; << 42 dydx[0] = y[3]/vModule ;
80 dydx[1] = y[4]*pModuleInverse ; << 43 dydx[1] = y[4]/vModule ;
81 dydx[2] = y[5]*pModuleInverse ; << 44 dydx[2] = y[5]/vModule ;
82 45
83 dydx[3] = cof1*(cof2*Field[3] + (y[4]*Field << 46 dydx[3] = fElectroMagCof*(Field[3] + (y[4]*Field[2] - y[5]*Field[1])/c_light -
>> 47 y[3]*vDotE/c_light/c_light )*gammaReci/vModule ;
84 48
85 dydx[4] = cof1*(cof2*Field[4] + (y[5]*Field << 49 dydx[4] = fElectroMagCof*(Field[4] + (y[5]*Field[0] - y[3]*Field[2])/c_light -
>> 50 y[4]*vDotE/c_light/c_light )*gammaReci/vModule ;
86 51
87 dydx[5] = cof1*(cof2*Field[5] + (y[3]*Field << 52 dydx[5] = fElectroMagCof*(Field[5] + (y[3]*Field[1] - y[4]*Field[0])/c_light -
88 << 53 y[5]*vDotE/c_light/c_light)*gammaReci/vModule ;
89 dydx[6] = 0.;//not used << 54 return ;
90 <<
91 // Lab Time of flight <<
92 // <<
93 dydx[7] = inverse_velocity; <<
94 <<
95 return; <<
96 } 55 }
97 56