| Geant4 Cross Reference |
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27 // -------------------------------------------------------------------
28 // GEANT4 Class file
29 //
30 // For information related to this code contact:
31 //
32 // File name: G4CrossSectionPatch
33 //
34 // Author:
35 //
36 // Creation date: 15 April 1999
37 //
38 // Modifications:
39 //
40 // -------------------------------------------------------------------
41
42 #include "globals.hh"
43 #include "G4CrossSectionPatch.hh"
44 #include "G4VCrossSectionSource.hh"
45 #include "G4KineticTrack.hh"
46 #include "G4CrossSectionVector.hh"
47
48 G4CrossSectionPatch::G4CrossSectionPatch()
49 { }
50
51
52 G4CrossSectionPatch::~G4CrossSectionPatch()
53 { }
54
55
56 G4bool G4CrossSectionPatch::operator==(const G4CrossSectionPatch &right) const
57 {
58 return (this == (G4CrossSectionPatch*) &right);
59 }
60
61
62 G4bool G4CrossSectionPatch::operator!=(const G4CrossSectionPatch &right) const
63 {
64 return (this != (G4CrossSectionPatch*) &right);
65 }
66
67
68 G4double G4CrossSectionPatch::CrossSection(const G4KineticTrack& trk1,
69 const G4KineticTrack& trk2) const
70 {
71 // The cross section is provided by one of the components, according to their energy
72 // validity range
73
74 G4double crossSection = 0.;
75 G4double ecm = (trk1.Get4Momentum() + trk2.Get4Momentum()).mag();
76
77 const G4CrossSectionVector* components = GetComponents();
78 if (components != 0)
79 {
80 std::size_t nComponents = this->GetComponents()->size();
81
82 for (std::size_t i=0; i<nComponents; ++i)
83 {
84 G4CrossSectionSourcePtr componentPtr = (*components)[i];
85 G4VCrossSectionSource* component = componentPtr();
86 if (component->IsValid(ecm))
87 {
88 crossSection = component->CrossSection(trk1,trk2);
89 }
90 else if (i < (nComponents - 1) )
91 {
92 G4CrossSectionSourcePtr nextPtr = (*components)[i+1];
93 G4VCrossSectionSource* next = nextPtr();
94 if (ecm > component->HighLimit() && ecm < next->LowLimit())
95 {
96 // Merge cross-sections in transition region between two validity ranges
97 crossSection = Transition(trk1,trk2,component,next);
98 }
99 }
100 }
101 }
102
103 return crossSection;
104 }
105
106
107 G4bool G4CrossSectionPatch::IsValid(G4double e) const
108 {
109 // The Patch is valid if any of its components are valid
110 G4bool answer = false;
111 const G4CrossSectionVector* components = GetComponents();
112 if (components != 0)
113 {
114 std::size_t n = components->size();
115 for (std::size_t i=0; i<n; ++i)
116 {
117 G4CrossSectionSourcePtr componentPtr = (*components)[i];
118 G4VCrossSectionSource* component = componentPtr();
119 if (component->IsValid(e))
120 {
121 answer = true;
122 break;
123 }
124 }
125 }
126 return answer;
127 }
128
129
130 G4double G4CrossSectionPatch::Transition(const G4KineticTrack& trk1, const G4KineticTrack& trk2,
131 const G4VCrossSectionSource* comp1,
132 const G4VCrossSectionSource* comp2) const
133 {
134 //Merge two cross sections in the transition region between their validity ranges
135
136 G4double crossSection = 0.;
137
138 G4double ecm = (trk1.Get4Momentum() + trk2.Get4Momentum()).mag();
139 G4double sigma1 = comp1->CrossSection(trk1,trk2);
140 G4double sigma2 = comp2->CrossSection(trk1,trk2);
141 G4double denom = comp2->LowLimit() - comp1->HighLimit();
142 G4double diff = ecm - comp1->HighLimit();
143 if (denom > 0. && diff > 0.)
144 {
145 G4double ratio = diff / denom;
146 crossSection = (1.- ratio) * sigma1 + ratio * sigma2;
147 }
148
149 return crossSection;
150 }
151
152
153 G4double G4CrossSectionPatch::Transition(G4double ecm,
154 G4double sigma1, G4double sigma2,
155 G4double e1, G4double e2) const
156 {
157 //Merge two cross sections in the transition region between their validity ranges
158
159 G4double crossSection = 0.;
160
161 G4double denom = e2 - e1;
162 G4double diff = ecm - e1;
163 if (denom > 0. && diff > 0.)
164 {
165 G4double ratio = diff / denom;
166 crossSection = (1.- ratio) * sigma1 + ratio * sigma2;
167 }
168
169 return crossSection;
170 }
171
172