| Geant4 Cross Reference |
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25 //
26
27 #include "G4ErrorEnergyLoss.hh"
28 #include "G4EnergyLossForExtrapolator.hh"
29 #include "G4ErrorPropagatorData.hh"
30
31 //-------------------------------------------------------------------
32 G4ErrorEnergyLoss::G4ErrorEnergyLoss(const G4String& processName,
33 G4ProcessType type)
34 : G4VContinuousProcess(processName, type)
35 {
36 if (verboseLevel>2) {
37 G4cout << GetProcessName() << " is created " << G4endl;
38 }
39
40 theELossForExtrapolator = new G4EnergyLossForExtrapolator;
41 theStepLimit = 1.*CLHEP::mm;
42 }
43
44 //-------------------------------------------------------------------
45 void G4ErrorEnergyLoss::InstantiateEforExtrapolator()
46 {}
47
48 //-------------------------------------------------------------------
49 G4ErrorEnergyLoss::~G4ErrorEnergyLoss()
50 {
51 delete theELossForExtrapolator;
52 }
53
54 //-------------------------------------------------------------------
55
56 G4bool G4ErrorEnergyLoss::IsApplicable(const G4ParticleDefinition& aParticleType)
57 {
58 return (aParticleType.GetPDGCharge() != 0);
59 }
60
61 //-------------------------------------------------------------------
62 G4VParticleChange*
63 G4ErrorEnergyLoss::AlongStepDoIt(const G4Track& aTrack, const G4Step& aStep)
64 {
65 aParticleChange.Initialize(aTrack);
66
67 G4ErrorPropagatorData* g4edata = G4ErrorPropagatorData::GetErrorPropagatorData();
68
69 G4double kinEnergyStart = aTrack.GetKineticEnergy();
70 G4double step_length = aStep.GetStepLength();
71
72 const G4Material* aMaterial = aTrack.GetMaterial();
73 const G4ParticleDefinition* aParticleDef = aTrack.GetDynamicParticle()->GetDefinition();
74 G4double kinEnergyEnd = kinEnergyStart;
75
76 // backward - energy increased
77 if( g4edata->GetMode() == G4ErrorMode(G4ErrorMode_PropBackwards) ) {
78 kinEnergyEnd = theELossForExtrapolator->EnergyBeforeStep( kinEnergyStart,
79 step_length,
80 aMaterial,
81 aParticleDef );
82 G4double kinEnergyHalfStep = (kinEnergyStart + kinEnergyEnd) * 0.5;
83
84 #ifdef G4VERBOSE
85 if(G4ErrorPropagatorData::verbose() >= 3 )
86 G4cout << " G4ErrorEnergyLoss FWD end " << kinEnergyEnd
87 << " halfstep " << kinEnergyHalfStep << G4endl;
88 #endif
89
90 //--- rescale to energy lost at 1/2 step
91 kinEnergyEnd = theELossForExtrapolator->EnergyBeforeStep( kinEnergyHalfStep,
92 step_length,
93 aMaterial,
94 aParticleDef );
95 kinEnergyEnd = kinEnergyStart - (kinEnergyHalfStep - kinEnergyEnd );
96
97 // forward - energy decreased
98 } else {
99 kinEnergyEnd = theELossForExtrapolator->EnergyAfterStep( kinEnergyStart,
100 step_length,
101 aMaterial,
102 aParticleDef );
103 G4double kinEnergyHalfStep = (kinEnergyStart + kinEnergyEnd) * 0.5;
104 #ifdef G4VERBOSE
105 if(G4ErrorPropagatorData::verbose() >= 3 )
106 G4cout << " G4ErrorEnergyLoss BCKD end " << kinEnergyEnd
107 << " halfstep " << kinEnergyHalfStep << G4endl;
108 #endif
109
110 //--- rescale to energy lost at 1/2 step
111 kinEnergyEnd = theELossForExtrapolator->EnergyAfterStep( kinEnergyHalfStep,
112 step_length,
113 aMaterial,
114 aParticleDef );
115 kinEnergyEnd = kinEnergyStart - (kinEnergyHalfStep - kinEnergyEnd );
116 }
117
118 G4double edepo = kinEnergyEnd - kinEnergyStart;
119
120 #ifdef G4VERBOSE
121 if( G4ErrorPropagatorData::verbose() >= 2 )
122 G4cout << "AlongStepDoIt Estart= " << kinEnergyStart << " Eend " << kinEnergyEnd
123 << " Ediff " << kinEnergyStart-kinEnergyEnd << " step= " << step_length
124 << " mate= " << aMaterial->GetName()
125 << " particle= " << aParticleDef->GetParticleName() << G4endl;
126 #endif
127
128 aParticleChange.ClearDebugFlag();
129 aParticleChange.ProposeLocalEnergyDeposit( edepo );
130 aParticleChange.SetNumberOfSecondaries(0);
131
132 aParticleChange.ProposeEnergy( kinEnergyEnd );
133
134 return &aParticleChange;
135 }
136
137
138 //-------------------------------------------------------------------
139 G4double G4ErrorEnergyLoss::GetContinuousStepLimit(const G4Track& aTrack,
140 G4double, G4double, G4double& )
141 {
142 G4double ekin = aTrack.GetKineticEnergy();
143 const G4Material* mat = aTrack.GetMaterial();
144 const G4ParticleDefinition* part =
145 aTrack.GetDynamicParticle()->GetDefinition();
146 G4double range = theELossForExtrapolator->ComputeRange(ekin, part, mat);
147 G4double delta = std::max(range*theFractionLimit, theStepLimit);
148 #ifdef G4VERBOSE
149 if(G4ErrorPropagatorData::verbose() >= 2 ) {
150 G4cout << " G4ErrorEnergyLoss: limiting Step " << delta
151 << " energy(GeV) " << ekin / CLHEP::GeV
152 << " for " << part->GetParticleName() << G4endl;
153 }
154 #endif
155 return delta;
156 }
157