| Geant4 Cross Reference |
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25 //
26 //
27
28 #include "globals.hh"
29 #include "G4SystemOfUnits.hh"
30 #include "G4CollisionComposite.hh"
31 #include "G4VCollision.hh"
32 #include "G4CollisionVector.hh"
33 #include "G4KineticTrack.hh"
34 #include "G4KineticTrackVector.hh"
35 #include "G4VCrossSectionSource.hh"
36 #include "G4HadTmpUtil.hh"
37 #include "G4AutoLock.hh"
38
39 const G4int G4CollisionComposite::nPoints = 32;
40
41 const G4double G4CollisionComposite::theT[nPoints] =
42 {.01, .03, .05, .1, .15, .2, .3, .4, .5, .6, .7, .8, .9, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.5, 3.0, 3.5, 4.0, 5.0, 6.0, 8.0, 10., 15, 20, 50, 100};
43
44 G4CollisionComposite::G4CollisionComposite()
45 {
46 G4MUTEXINIT( bufferMutex );
47 }
48
49
50 G4CollisionComposite::~G4CollisionComposite()
51 {
52 G4MUTEXDESTROY(bufferMutex);
53 std::for_each(components.begin(), components.end(), G4Delete());
54 }
55
56
57 G4double G4CollisionComposite::CrossSection(const G4KineticTrack& trk1,
58 const G4KineticTrack& trk2) const
59 {
60 G4double crossSect = 0.;
61 const G4VCrossSectionSource* xSource = GetCrossSectionSource();
62 if (xSource != 0)
63 // There is a total cross section for this Collision
64 {
65 crossSect = xSource->CrossSection(trk1,trk2);
66 }
67 else
68 {
69 G4AutoLock l(&bufferMutex);
70 // waiting for mutable to enable buffering.
71 const_cast<G4CollisionComposite *>(this)->BufferCrossSection(trk1.GetDefinition(), trk2.GetDefinition());
72 // G4cerr << "Buffer filled, reying with sqrts = "<< (trk1.Get4Momentum()+trk2.Get4Momentum()).mag() <<G4endl;
73 crossSect = BufferedCrossSection(trk1,trk2);
74 }
75 return crossSect;
76 }
77
78
79 G4KineticTrackVector* G4CollisionComposite::FinalState(const G4KineticTrack& trk1,
80 const G4KineticTrack& trk2) const
81 {
82 std::vector<G4double> cxCache;
83 G4double partialCxSum = 0.0;
84
85 size_t i;
86 for (i=0; i<components.size(); i++)
87 {
88 G4double partialCx;
89 // cout << "comp" << i << " " << components[i]()->GetName();
90 if (components[i]->IsInCharge(trk1,trk2))
91 {
92 partialCx = components[i]->CrossSection(trk1,trk2);
93 }
94 else
95 {
96 partialCx = 0.0;
97 }
98 // cout << " cx=" << partialCx << endl;
99 partialCxSum += partialCx;
100 cxCache.push_back(partialCx);
101 }
102
103 G4double random = G4UniformRand()*partialCxSum;
104 G4double running = 0;
105 for (i=0; i<cxCache.size(); i++)
106 {
107 running += cxCache[i];
108 if (running > random)
109 {
110 return components[i]->FinalState(trk1, trk2);
111 }
112 }
113 // G4cerr <<"in charge = "<<IsInCharge(trk1, trk2)<<G4endl;
114 // G4cerr <<"Cross-section = "<<CrossSection(trk1, trk2)/millibarn<<" "<<running<<" "<<cxCache.size()<<G4endl;
115 // G4cerr <<"Names = "<<trk1.GetDefinition()->GetParticleName()<<", "<<trk2.GetDefinition()->GetParticleName()<<G4endl;
116 // throw G4HadronicException(__FILE__, __LINE__, "G4CollisionComposite: no final state found!");
117 return NULL;
118 }
119
120
121 G4bool G4CollisionComposite::IsInCharge(const G4KineticTrack& trk1,
122 const G4KineticTrack& trk2) const
123 {
124 G4bool isInCharge = false;
125
126 // The composite is in charge if any of its components is in charge
127
128 const G4CollisionVector* comps = GetComponents();
129 if (comps)
130 {
131 G4CollisionVector::const_iterator iter;
132 for (iter = comps->begin(); iter != comps->end(); ++iter)
133 {
134 if ( ((*iter))->IsInCharge(trk1,trk2) ) isInCharge = true;
135 }
136 }
137
138 return isInCharge;
139 }
140
141 void G4CollisionComposite::
142 BufferCrossSection(const G4ParticleDefinition * aP, const G4ParticleDefinition * bP)
143 {
144 // check if already buffered
145 size_t i;
146 for(i=0; i<theBuffer.size(); i++)
147 {
148 if(theBuffer[i].InCharge(aP, bP)) return;
149 }
150 // G4cerr << "Buffering for "<<aP->GetParticleName()<<" "<<bP->GetParticleName()<<G4endl;
151
152 // buffer the new one.
153 G4CrossSectionBuffer aNewBuff(aP, bP);
154 size_t maxE=nPoints;
155 for(size_t tt=0; tt<maxE; tt++)
156 {
157 G4double aT = theT[tt]*GeV;
158 G4double crossSect = 0;
159 // The total cross-section is summed over all the component channels
160
161 //A.R. 28-Sep-2012 Fix reproducibility problem
162 // Assign the kinetic energy to the lightest of the
163 // two particles, instead to the first one always.
164 G4double atime = 0;
165 G4double btime = 0;
166 G4ThreeVector aPosition(0,0,0);
167 G4ThreeVector bPosition(0,0,0);
168 G4double aM = aP->GetPDGMass();
169 G4double bM = bP->GetPDGMass();
170 G4double aE = aM;
171 G4double bE = bM;
172 G4ThreeVector aMom(0,0,0);
173 G4ThreeVector bMom(0,0,0);
174 if ( aM <= bM ) {
175 aE += aT;
176 aMom = G4ThreeVector(0,0,std::sqrt(aE*aE-aM*aM));
177 } else {
178 bE += aT;
179 bMom = G4ThreeVector(0,0,std::sqrt(bE*bE-bM*bM));
180 }
181 G4LorentzVector a4Momentum(aE, aMom);
182 G4LorentzVector b4Momentum(bE, bMom);
183 G4KineticTrack a(aP, atime, aPosition, a4Momentum);
184 G4KineticTrack b(bP, btime, bPosition, b4Momentum);
185
186 for (i=0; i<components.size(); i++)
187 {
188 if(components[i]->IsInCharge(a,b))
189 {
190 crossSect += components[i]->CrossSection(a,b);
191 }
192 }
193 G4double sqrts = (a4Momentum+b4Momentum).mag();
194 aNewBuff.push_back(sqrts, crossSect);
195 }
196 theBuffer.push_back(std::move(aNewBuff));
197 // theBuffer.back().Print();
198 }
199
200
201 G4double G4CollisionComposite::
202 BufferedCrossSection(const G4KineticTrack& trk1, const G4KineticTrack& trk2) const
203 {
204 for(size_t i=0; i<theBuffer.size(); i++)
205 {
206 if(theBuffer[i].InCharge(trk1.GetDefinition(), trk2.GetDefinition()))
207 {
208 return theBuffer[i].CrossSection(trk1, trk2);
209 }
210 }
211 throw G4HadronicException(__FILE__, __LINE__, "G4CollisionComposite::BufferedCrossSection - Blitz !!");
212 return 0;
213 }
214
215