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25 // 25 //
26 // G4BFieldIntegrationDriver implementation 26 // G4BFieldIntegrationDriver implementation
27 // 27 //
28 // Specialized integration driver for pure mag 28 // Specialized integration driver for pure magnetic field
29 // 29 //
30 // Author: D.Sorokin 30 // Author: D.Sorokin
31 // ------------------------------------------- 31 // --------------------------------------------------------------------
32 32
33 #include "G4BFieldIntegrationDriver.hh" 33 #include "G4BFieldIntegrationDriver.hh"
34 34
35 #include "G4FieldTrack.hh" 35 #include "G4FieldTrack.hh"
36 #include "G4FieldUtils.hh" 36 #include "G4FieldUtils.hh"
37 #include "G4Exception.hh" 37 #include "G4Exception.hh"
38 #include "G4PhysicalConstants.hh" 38 #include "G4PhysicalConstants.hh"
39 #include "G4SystemOfUnits.hh" 39 #include "G4SystemOfUnits.hh"
40 #include "templates.hh" 40 #include "templates.hh"
41 41
42 42
43 namespace { 43 namespace {
44 44
45 G4Mag_EqRhs* toMagneticEquation(G4EquationOfMo 45 G4Mag_EqRhs* toMagneticEquation(G4EquationOfMotion* equation)
46 { 46 {
47 auto e = dynamic_cast<G4Mag_EqRhs*>(equati 47 auto e = dynamic_cast<G4Mag_EqRhs*>(equation);
48 48
49 if (e == nullptr) << 49 if (!e)
50 { 50 {
51 G4Exception("G4BFieldIntegrationDriver 51 G4Exception("G4BFieldIntegrationDriver::G4BFieldIntegrationDriver",
52 "GeomField0003", FatalErro 52 "GeomField0003", FatalErrorInArgument,
53 "Works only with G4Mag_EqR 53 "Works only with G4Mag_EqRhs");
54 } 54 }
55 55
56 return e; 56 return e;
57 } 57 }
58 58
59 } // namespace 59 } // namespace
60 60
61 61
62 G4BFieldIntegrationDriver::G4BFieldIntegration 62 G4BFieldIntegrationDriver::G4BFieldIntegrationDriver(
63 std::unique_ptr<G4VIntegrationDriver> smal 63 std::unique_ptr<G4VIntegrationDriver> smallStepDriver,
64 std::unique_ptr<G4VIntegrationDriver> larg 64 std::unique_ptr<G4VIntegrationDriver> largeStepDriver)
65 : fSmallStepDriver(std::move(smallStepDriv 65 : fSmallStepDriver(std::move(smallStepDriver)),
66 fLargeStepDriver(std::move(largeStepDriv 66 fLargeStepDriver(std::move(largeStepDriver)),
67 fCurrDriver(fSmallStepDriver.get()), 67 fCurrDriver(fSmallStepDriver.get()),
68 fEquation(toMagneticEquation(fCurrDriver 68 fEquation(toMagneticEquation(fCurrDriver->GetEquationOfMotion()))
69 { 69 {
70 if (fSmallStepDriver->GetEquationOfMotion( 70 if (fSmallStepDriver->GetEquationOfMotion()
71 != fLargeStepDriver->GetEquationOfMotion( 71 != fLargeStepDriver->GetEquationOfMotion())
72 { 72 {
73 G4Exception("G4BFieldIntegrationDriver 73 G4Exception("G4BFieldIntegrationDriver Constructor:",
74 "GeomField1001", FatalExce 74 "GeomField1001", FatalException, "different EoM");
75 } 75 }
76 } 76 }
77 77
78 G4double G4BFieldIntegrationDriver::AdvanceCho 78 G4double G4BFieldIntegrationDriver::AdvanceChordLimited(G4FieldTrack& yCurrent,
79 79 G4double stepMax,
80 80 G4double epsStep,
81 81 G4double chordDistance)
82 { 82 {
83 const G4double radius = CurvatureRadius(yC 83 const G4double radius = CurvatureRadius(yCurrent);
84 84
85 G4VIntegrationDriver* driver = nullptr; 85 G4VIntegrationDriver* driver = nullptr;
86 if (chordDistance < 2 * radius) 86 if (chordDistance < 2 * radius)
87 { 87 {
88 stepMax = std::min(stepMax, twopi * ra 88 stepMax = std::min(stepMax, twopi * radius);
89 driver = fSmallStepDriver.get(); 89 driver = fSmallStepDriver.get();
90 ++fSmallDriverSteps; 90 ++fSmallDriverSteps;
91 } else 91 } else
92 { 92 {
93 driver = fLargeStepDriver.get(); 93 driver = fLargeStepDriver.get();
94 ++fLargeDriverSteps; 94 ++fLargeDriverSteps;
95 } 95 }
96 96
97 if (driver != fCurrDriver) 97 if (driver != fCurrDriver)
98 { 98 {
99 driver->OnComputeStep(); 99 driver->OnComputeStep();
100 } 100 }
101 101
102 fCurrDriver = driver; 102 fCurrDriver = driver;
103 103
104 return fCurrDriver->AdvanceChordLimited(yC 104 return fCurrDriver->AdvanceChordLimited(yCurrent, stepMax,
105 ep 105 epsStep, chordDistance);
106 } 106 }
107 107
108 void 108 void
109 G4BFieldIntegrationDriver::SetEquationOfMotion 109 G4BFieldIntegrationDriver::SetEquationOfMotion(G4EquationOfMotion* equation)
110 { 110 {
111 fEquation = toMagneticEquation(equation); 111 fEquation = toMagneticEquation(equation);
112 fSmallStepDriver->SetEquationOfMotion(equa 112 fSmallStepDriver->SetEquationOfMotion(equation);
113 fLargeStepDriver->SetEquationOfMotion(equa 113 fLargeStepDriver->SetEquationOfMotion(equation);
114 } 114 }
115 115
116 G4double 116 G4double
117 G4BFieldIntegrationDriver::CurvatureRadius(con 117 G4BFieldIntegrationDriver::CurvatureRadius(const G4FieldTrack& track) const
118 { 118 {
119 G4double field[G4Field::MAX_NUMBER_OF_COMP 119 G4double field[G4Field::MAX_NUMBER_OF_COMPONENTS];
120 120
121 GetFieldValue(track, field); 121 GetFieldValue(track, field);
122 122
123 const G4double Bmag2 = field[0] * field[ 123 const G4double Bmag2 = field[0] * field[0]
124 + field[1] * field[ 124 + field[1] * field[1]
125 + field[2] * field[ 125 + field[2] * field[2] ;
126 if (Bmag2 == 0.0 ) 126 if (Bmag2 == 0.0 )
127 { 127 {
128 return DBL_MAX; 128 return DBL_MAX;
129 } 129 }
130 130
131 const G4double momentum2 = track.GetMoment 131 const G4double momentum2 = track.GetMomentum().mag2();
132 const G4double fCof_inv = eplus / std::abs 132 const G4double fCof_inv = eplus / std::abs(fEquation->FCof());
133 133
134 return std::sqrt(momentum2 / Bmag2) * fCof 134 return std::sqrt(momentum2 / Bmag2) * fCof_inv;
135 } 135 }
136 136
137 void 137 void
138 G4BFieldIntegrationDriver::GetFieldValue(const 138 G4BFieldIntegrationDriver::GetFieldValue(const G4FieldTrack& track,
139 G4dou 139 G4double Field[] ) const
140 { 140 {
141 G4ThreeVector pos= track.GetPosition(); 141 G4ThreeVector pos= track.GetPosition();
142 G4double positionTime[4]= { pos.x(), pos.y 142 G4double positionTime[4]= { pos.x(), pos.y(), pos.z(),
143 track.GetLabTi 143 track.GetLabTimeOfFlight() } ;
144 144
145 fEquation->GetFieldValue(positionTime, Fie 145 fEquation->GetFieldValue(positionTime, Field);
146 } 146 }
147 147
148 void G4BFieldIntegrationDriver::PrintStatistic 148 void G4BFieldIntegrationDriver::PrintStatistics() const
149 { 149 {
150 const auto totSteps = fSmallDriverSteps + 150 const auto totSteps = fSmallDriverSteps + fLargeDriverSteps;
151 const auto toFraction = [&](double value) 151 const auto toFraction = [&](double value) { return value / totSteps * 100; };
152 152
153 G4cout << "============= G4BFieldIntegrati 153 G4cout << "============= G4BFieldIntegrationDriver statistics ===========\n"
154 << "total steps " << totSteps << " 154 << "total steps " << totSteps << " "
155 << "smallDriverSteps " << toFractio 155 << "smallDriverSteps " << toFraction(fSmallDriverSteps) << " "
156 << "largeDriverSteps " << toFractio 156 << "largeDriverSteps " << toFraction(fLargeDriverSteps) << "\n"
157 << "=============================== 157 << "======================================\n";
158 } 158 }
159 159