| Geant4 Cross Reference |
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25 //
26 // G4InteractionLawPhysical
27 // -------------------------------------------
28
29 #include "G4InteractionLawPhysical.hh"
30 #include "Randomize.hh"
31
32 G4InteractionLawPhysical::G4InteractionLawPhys
33 : G4VBiasingInteractionLaw(name)
34 {}
35
36 G4InteractionLawPhysical::~G4InteractionLawPhy
37 {}
38
39 void G4InteractionLawPhysical::SetPhysicalCros
40 {
41 if (crossSection < 0.0)
42 {
43 G4Exception("G4InteractionLawPhysical::Set
44 "BIAS.GEN.14", JustWarning,
45 "Cross-section value passed is
46 crossSection = 0.0;
47 }
48 fCrossSectionDefined = true;
49 fCrossSection = crossSection;
50 }
51
52 G4double G4InteractionLawPhysical::
53 ComputeEffectiveCrossSectionAt(G4double) const
54 {
55 if (!fCrossSectionDefined)
56 {
57 G4Exception("G4InteractionLawPhysical::Com
58 "BIAS.GEN.15", JustWarning,
59 "Cross-section value requested
60 }
61 return fCrossSection;
62 }
63
64 G4double G4InteractionLawPhysical::
65 ComputeNonInteractionProbabilityAt(G4double st
66 {
67 if (!fCrossSectionDefined)
68 {
69 G4Exception("G4InteractionLawPhysical::Com
70 "BIAS.GEN.16", JustWarning,
71 "Non interaction probabitlity
72 }
73 // -- allows zero cross-section case, by con
74 if ( fCrossSection == 0.0 ) return 1.0;
75 else return std::exp(-fCrossSection*stepLeng
76 }
77
78 G4double G4InteractionLawPhysical::SampleInter
79 {
80 if ( !fCrossSectionDefined || fCrossSection
81 {
82 G4Exception("G4InteractionLawPhysical::Sam
83 "BIAS.GEN.17", FatalException,
84 "Trying to sample while cross-
85 }
86 if ( fCrossSection == 0.0 ) return DBL_MAX;
87
88 fNumberOfInteractionLength = -std::log( G4Un
89 return fNumberOfInteractionLength/fCrossSect
90 }
91
92 G4double G4InteractionLawPhysical::
93 UpdateInteractionLengthForStep(G4double truePa
94 {
95 fNumberOfInteractionLength -= truePathLength
96
97 if ( fNumberOfInteractionLength < 0 )
98 {
99 G4ExceptionDescription ed;
100 ed << " Negative number of interaction len
101 << "' " << fNumberOfInteractionLength <
102 G4Exception("G4InteractionLawPhysical::Upd
103 "BIAS.GEN.13", JustWarning, ed
104 fNumberOfInteractionLength = 0.;
105 }
106 return fNumberOfInteractionLength/fCrossSec
107 }
108