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25 // 25 //
26 // G4InteractionLawPhysical <<
27 // ------------------------------------------- <<
28 <<
29 #include "G4InteractionLawPhysical.hh" 26 #include "G4InteractionLawPhysical.hh"
30 #include "Randomize.hh" 27 #include "Randomize.hh"
31 28
32 G4InteractionLawPhysical::G4InteractionLawPhys << 29 G4InteractionLawPhysical::G4InteractionLawPhysical(G4String name)
33 : G4VBiasingInteractionLaw(name) << 30 : G4VBiasingInteractionLaw(name),
>> 31 fCrossSection(0.0),
>> 32 fCrossSectionDefined(false),
>> 33 fNumberOfInteractionLength(-1.0)
34 {} 34 {}
35 35
36 G4InteractionLawPhysical::~G4InteractionLawPhy 36 G4InteractionLawPhysical::~G4InteractionLawPhysical()
37 {} 37 {}
38 38
39 void G4InteractionLawPhysical::SetPhysicalCros 39 void G4InteractionLawPhysical::SetPhysicalCrossSection(G4double crossSection)
40 { 40 {
41 if (crossSection < 0.0) 41 if (crossSection < 0.0)
42 { << 42 {
43 G4Exception("G4InteractionLawPhysical::Set << 43 G4Exception("G4InteractionLawPhysical::SetPhysicalCrossSection(..)",
44 "BIAS.GEN.14", JustWarning, << 44 "BIAS.GEN.14",
45 "Cross-section value passed is << 45 JustWarning,
46 crossSection = 0.0; << 46 "Cross-section value passed is negative. It is set to zero !");
47 } << 47 crossSection = 0.0;
>> 48 }
48 fCrossSectionDefined = true; 49 fCrossSectionDefined = true;
49 fCrossSection = crossSection; << 50 fCrossSection = crossSection;
50 } 51 }
51 52
52 G4double G4InteractionLawPhysical:: << 53 G4double G4InteractionLawPhysical::ComputeEffectiveCrossSectionAt(G4double) const
53 ComputeEffectiveCrossSectionAt(G4double) const <<
54 { 54 {
55 if (!fCrossSectionDefined) << 55 if (!fCrossSectionDefined) G4Exception("G4InteractionLawPhysical::ComputeEffectiveCrossSection(..)",
56 { << 56 "BIAS.GEN.15",
57 G4Exception("G4InteractionLawPhysical::Com << 57 JustWarning,
58 "BIAS.GEN.15", JustWarning, << 58 "Cross-section value requested, but has not been defined yet. Assumes 0 !");
59 "Cross-section value requested <<
60 } <<
61 return fCrossSection; 59 return fCrossSection;
62 } 60 }
63 61
64 G4double G4InteractionLawPhysical:: << 62 G4double G4InteractionLawPhysical::ComputeNonInteractionProbabilityAt(G4double stepLength) const
65 ComputeNonInteractionProbabilityAt(G4double st <<
66 { 63 {
67 if (!fCrossSectionDefined) << 64 if (!fCrossSectionDefined) G4Exception("G4InteractionLawPhysical::ComputeNonInteractionProbability(..)",
68 { << 65 "BIAS.GEN.16",
69 G4Exception("G4InteractionLawPhysical::Com << 66 JustWarning,
70 "BIAS.GEN.16", JustWarning, << 67 "Non interaction probabitlity value requested, but cross section has not been defined yet. Assumes it to be 0 !");
71 "Non interaction probabitlity <<
72 } <<
73 // -- allows zero cross-section case, by con 68 // -- allows zero cross-section case, by convention:
74 if ( fCrossSection == 0.0 ) return 1.0; 69 if ( fCrossSection == 0.0 ) return 1.0;
75 else return std::exp(-fCrossSection*stepLeng 70 else return std::exp(-fCrossSection*stepLength);
76 } 71 }
77 72
78 G4double G4InteractionLawPhysical::SampleInter 73 G4double G4InteractionLawPhysical::SampleInteractionLength()
79 { 74 {
80 if ( !fCrossSectionDefined || fCrossSection << 75 if ( !fCrossSectionDefined || fCrossSection < 0.0 ) G4Exception("G4InteractionLawPhysical::Sample(..)",
81 { << 76 "BIAS.GEN.17",
82 G4Exception("G4InteractionLawPhysical::Sam << 77 FatalException,
83 "BIAS.GEN.17", FatalException, << 78 "Trying to sample while cross-section is not defined or < 0 !");
84 "Trying to sample while cross- <<
85 } <<
86 if ( fCrossSection == 0.0 ) return DBL_MAX; 79 if ( fCrossSection == 0.0 ) return DBL_MAX;
87 80
88 fNumberOfInteractionLength = -std::log( G4Un << 81 fNumberOfInteractionLength = -std::log( G4UniformRand() );
89 return fNumberOfInteractionLength/fCrossSect 82 return fNumberOfInteractionLength/fCrossSection;
90 } 83 }
91 84
92 G4double G4InteractionLawPhysical:: << 85
93 UpdateInteractionLengthForStep(G4double truePa << 86 G4double G4InteractionLawPhysical::UpdateInteractionLengthForStep(G4double truePathLength)
94 { 87 {
95 fNumberOfInteractionLength -= truePathLength 88 fNumberOfInteractionLength -= truePathLength*fCrossSection;
96 89
97 if ( fNumberOfInteractionLength < 0 ) 90 if ( fNumberOfInteractionLength < 0 )
98 { << 91 {
99 G4ExceptionDescription ed; << 92 G4ExceptionDescription ed;
100 ed << " Negative number of interaction len << 93 ed << " Negative number of interaction length for `" << GetName() << "' " << fNumberOfInteractionLength << ", set it to zero !" << G4endl;
101 << "' " << fNumberOfInteractionLength < << 94 G4Exception("G4InteractionLawPhysical::UpdateInteractionLengthForStep(...)",
102 G4Exception("G4InteractionLawPhysical::Upd << 95 "BIAS.GEN.13",
103 "BIAS.GEN.13", JustWarning, ed << 96 JustWarning,
104 fNumberOfInteractionLength = 0.; << 97 ed);
105 } << 98 fNumberOfInteractionLength = 0.;
>> 99 }
106 return fNumberOfInteractionLength/fCrossSec 100 return fNumberOfInteractionLength/fCrossSection;
107 } 101 }
108 102