| Geant4 Cross Reference |
1 // 1
2 // *******************************************
3 // * License and Disclaimer
4 // *
5 // * The Geant4 software is copyright of th
6 // * the Geant4 Collaboration. It is provided
7 // * conditions of the Geant4 Software License
8 // * LICENSE and available at http://cern.ch/
9 // * include a list of copyright holders.
10 // *
11 // * Neither the authors of this software syst
12 // * institutes,nor the agencies providing fin
13 // * work make any representation or warran
14 // * regarding this software system or assum
15 // * use. Please see the license in the file
16 // * for the full disclaimer and the limitatio
17 // *
18 // * This code implementation is the result
19 // * technical work of the GEANT4 collaboratio
20 // * By using, copying, modifying or distri
21 // * any work based on the software) you ag
22 // * use in resulting scientific publicati
23 // * acceptance of all terms of the Geant4 Sof
24 // *******************************************
25 //
26 #include "G4Absorber.hh"
27 #include "G4KineticTrack.hh"
28 #include "G4PionPlus.hh"
29 #include "G4PionMinus.hh"
30 #include "G4PionZero.hh"
31 #include "G4Proton.hh"
32 #include "G4Neutron.hh"
33
34 #include "G4PhysicalConstants.hh"
35 #include "G4SystemOfUnits.hh"
36 #include "G4LorentzRotation.hh"
37
38 G4Absorber::G4Absorber(G4double cutOnP)
39 {
40 theCutOnP = cutOnP;
41 theAbsorbers = new G4KineticTrackVector;
42 theProducts = new G4KineticTrackVector;
43 }
44
45
46 G4Absorber::~G4Absorber()
47 {
48 delete theAbsorbers;
49 delete theProducts;
50 }
51
52
53 bool G4Absorber::WillBeAbsorbed(const G4Kineti
54 {
55 // FixMe: actually only for pions
56 // if(kt.Get4Momentum().vect().mag() < theCut
57 // Cut on kinetic Energy...
58 if (kt.Get4Momentum().e() - kt.GetActualMass
59 {
60 if(kt.GetDefinition() == G4PionPlus::Pio
61 kt.GetDefinition() == G4PionZero::PionZero(
62 kt.GetDefinition() == G4PionMinus::PionMinu
63 {
64 return true;
65 }
66 }
67 return false;
68 }
69
70
71
72 G4bool G4Absorber::Absorb(G4KineticTrack & kt,
73 {
74 if(!FindAbsorbers(kt, tgt))
75 return false;
76 return FindProducts(kt);
77 }
78
79
80 G4bool G4Absorber::FindAbsorbers(G4KineticTrac
81 G4KineticTrackVector & tgt)
82 {
83 // Find a closest ( in space) pair of Nucleon
84 // pi+ can be absorbed on np or nn resultin
85 // pi- can be absorbed on np or pp resultin
86
87 // @GF: FindAbsorbers is unused, logic is seri
88
89 G4KineticTrack * kt1 = NULL;
90 G4KineticTrack * kt2 = NULL;
91 G4double dist1 = DBL_MAX; // dist to close
92 G4double dist2 = DBL_MAX; // dist to next
93 G4double charge1 = 0;
94 // G4double charge2 = 0; // charge2 is only
95 G4double charge0 = kt.GetDefinition()->GetPD
96 G4ThreeVector pos = kt.GetPosition();
97
98 std::vector<G4KineticTrack *>::iterator iter
99 for(iter = tgt.begin(); iter != tgt.end(); +
100 {
101 G4KineticTrack * curr = *iter;
102 G4double dist = (pos-curr->GetPosition()).
103 if(dist >= dist2)
104 continue;
105 if(dist < dist1)
106 {
107 if(dist1 == DBL_MAX) // accept 1st as a
108 {
109 kt1 = curr;
110 charge1 = kt1->GetDefinition()->GetPDGCharge
111 dist1 = dist;
112 continue;
113 }
114 if(dist2 == DBL_MAX) // accept the candi
115 { // @GF: should'nt we check if co
116 kt2 = kt1;
117 // charge2 = charge1;
118 dist2 = dist1;
119 kt1 = curr;
120 charge1 = kt1->GetDefinition()->GetPDGCharge
121 dist1 = dist;
122 continue;
123 }
124 // test the compatibility with charge conserva
125 G4double charge = curr->GetDefinition()-
126 if((charge0+charge1+charge < 0.) || //te
127 (charge0+charge1+charge) > 2*eplus)
128 { // incompatible: change kt1 with curr
129 kt1 = curr;
130 charge1 = charge;
131 dist1 = dist;
132 }
133 else
134 { // compatible: change kt1 with curr an
135 kt2 = kt1;
136 // charge2 = charge1;
137 dist2 = dist1;
138 kt1 = curr;
139 charge1 = charge;
140 dist1 = dist;
141 }
142 continue;
143 }
144 // here if dist1 < dist < dist2
145 if(dist2 == DBL_MAX) // accept the candida
146 {
147 kt2 = curr;
148 // charge2 = kt2->GetDefinition()->GetPDG
149 dist2 = dist;
150 continue;
151 }
152 // test the compatibility with charge conserva
153 G4double charge = curr->GetDefinition()->G
154 if((charge0+charge1+charge < 0.) ||
155 (charge0+charge1+charge) > 2*eplus)
156 continue; // incomatible: do nothing
157 // compatible: change kt2 with curr
158 kt2 = curr;
159 // charge2 = charge;
160 dist2 = dist;
161 }
162
163 theAbsorbers->clear(); // do not delete trac
164 if((kt1 == NULL) || (kt2 == NULL))
165 return false;
166
167 theAbsorbers->push_back(kt1);
168 theAbsorbers->push_back(kt2);
169 return true;
170 }
171
172
173
174 G4bool G4Absorber::FindProducts(G4KineticTrack
175 {
176 // Choose the products type
177 const G4ParticleDefinition * prod1;
178 const G4ParticleDefinition * prod2;
179 G4KineticTrack * abs1 = (*theAbsorbers)[0];
180 G4KineticTrack * abs2 = (*theAbsorbers)[1];
181
182 G4double charge = kt.GetDefinition()->GetPDG
183 if(charge == eplus)
184 { // a neutron become proton
185 prod1 = G4Proton::Proton();
186 if(abs1->GetDefinition() == G4Neutron::Neu
187 prod2 = abs2->GetDefinition();
188 else
189 prod2 = G4Proton::Proton();
190 }
191 else if(charge == -eplus)
192 { // a proton become neutron
193 prod1 = G4Neutron::Neutron();
194 if(abs1->GetDefinition() == G4Proton::Prot
195 prod2 = abs2->GetDefinition();
196 else
197 prod2 = G4Neutron::Neutron();
198 }
199 else // charge = 0: leave particle types un
200 {
201 prod1 = abs1->GetDefinition();
202 prod2 = abs2->GetDefinition();
203 }
204
205 // Translate to the CMS frame
206 G4LorentzVector momLab = kt.Get4Momentum()+a
207 abs2->Get4Momentum();
208 G4LorentzRotation toCMSFrame((-1)*momLab.boo
209 G4LorentzRotation toLabFrame(momLab.boostVec
210 G4LorentzVector momCMS = toCMSFrame*momLab;
211
212 // Evaluate the final momentum of products
213 G4double ms1 = prod1->GetPDGMass();
214 G4double ms2 = prod2->GetPDGMass();
215 G4double e0 = momCMS.e();
216 G4double squareP = (e0*e0*e0*e0-2*e0*e0*(ms1
217 (ms2*ms2-ms1*ms1)*(ms2*ms2-ms1*ms1))/(4*e0
218 // if(squareP < 0) // should never happen
219 // squareP = 0;
220 G4ThreeVector mom1CMS = GetRandomDirection()
221 mom1CMS = std::sqrt(squareP)*mom1CMS;
222 G4LorentzVector final4Mom1CMS(mom1CMS, std::
223 G4LorentzVector final4Mom2CMS((-1)*mom1CMS,
224
225 // Go back to the lab frame
226 G4LorentzVector mom1 = toLabFrame*final4Mom1
227 G4LorentzVector mom2 = toLabFrame*final4Mom2
228
229 // ------ debug
230 /*
231 G4LorentzVector temp = mom1+mom2;
232
233 cout << (1/MeV)*momLab.x() << " " << (1/MeV)
234 << (1/MeV)*momLab.z() << " " << (1/MeV)
235 << (1/MeV)*momLab.vect().mag() << " " <
236 << (1/MeV)*temp.x() << " " << (1/MeV)*t
237 << (1/MeV)*temp.z() << " " << (1/MeV)*t
238 << (1/MeV)*temp.vect().mag() << " " <<
239 << (1/MeV)*std::sqrt(squareP) << endl;
240
241 */
242 // ------ end debug
243
244 // Build two new kinetic tracks and add to pro
245 G4KineticTrack * kt1 = new G4KineticTrack(pr
246 mom1);
247 G4KineticTrack * kt2 = new G4KineticTrack(pr
248 mom2);
249 // ------ debug
250 /*
251 G4LorentzVector initialMom1 = abs1->Get4Mome
252 G4LorentzVector initialMom2 = abs2->Get4Mome
253 G4LorentzVector pion4MomCMS = toCMSFrame*kt.
254 cout << (1/MeV)*initialMom1.x() << " " << (1
255 << (1/MeV)*initialMom1.z() << " " << (1
256 << (1/MeV)*initialMom1.vect().mag() <<
257 << (1/MeV)*initialMom2.x() << " " << (1
258 << (1/MeV)*initialMom2.z() << " " << (1
259 << (1/MeV)*initialMom2.vect().mag() <<
260 << (1/MeV)*mom1.x() << " " << (1/MeV)*m
261 << (1/MeV)*mom1.z() << " " << (1/MeV)*m
262 << (1/MeV)*mom1.vect().mag() << " "
263 << (1/MeV)*mom2.x() << " " << (1/MeV)*m
264 << (1/MeV)*mom2.z() << " " << (1/MeV)*m
265 << (1/MeV)*mom2.vect().mag() << " "
266 << (1/MeV)*pion4MomCMS.x() << " " << (1
267 << (1/MeV)*pion4MomCMS.z() << " " << (1
268 << (1/MeV)*pion4MomCMS.vect().mag() <<
269 << (1/MeV)*final4Mom1CMS.x() << " " <<
270 << (1/MeV)*final4Mom1CMS.z() << " " <<
271 << (1/MeV)*final4Mom1CMS.vect().mag() <
272 << (1/MeV)*final4Mom2CMS.x() << " " <<
273 << (1/MeV)*final4Mom2CMS.z() << " " <<
274 << (1/MeV)*final4Mom2CMS.vect().mag() <
275 */
276 // ------ end debug
277
278 theProducts->clear();
279 theProducts->push_back(kt1);
280 theProducts->push_back(kt2);
281 return true;
282 }
283
284
285
286 G4ThreeVector G4Absorber::GetRandomDirection()
287 {
288 G4double theta = 2.0*G4UniformRand()-1.0;
289 theta = std::acos(theta);
290 G4double phi = G4UniformRand()*2*pi;
291 G4ThreeVector direction(std::sin(theta)*std:
292 return direction;
293 }
294
295
296
297
298
299
300
301