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G4Scatterer.cc
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26 // $Id: G4Scatterer.cc,v 1.16 2010-03-12 15:45:18 gunter Exp $ //
27 //
28 
29 #include <vector>
30 
31 #include "globals.hh"
32 #include "G4PhysicalConstants.hh"
33 #include "G4SystemOfUnits.hh"
34 #include "G4ios.hh"
35 #include "G4Scatterer.hh"
36 #include "G4KineticTrack.hh"
37 #include "G4ThreeVector.hh"
38 #include "G4LorentzRotation.hh"
39 #include "G4LorentzVector.hh"
40 
41 #include "G4CollisionNN.hh"
42 #include "G4CollisionPN.hh"
44 
46 #include "G4HadTmpUtil.hh"
47 #include "G4Pair.hh"
48 #include "G4AutoLock.hh"
49 
50 //Mutex for control of shared resource
51 namespace {
52  G4Mutex collisions_mutex = G4MUTEX_INITIALIZER;
53  G4bool setupDone = false;
54 }
55 
56 // Declare the categories of collisions the Scatterer can handle
57 typedef GROUP2(G4CollisionNN, G4CollisionMesonBaryon) theChannels;
58 
59 G4CollisionVector G4Scatterer::collisions;
60 
61 //----------------------------------------------------------------------------
62 
64 {
65  G4AutoLock l(&collisions_mutex);
66  if ( ! setupDone )
67  {
68  Register aR;
69  G4ForEach<theChannels>::Apply(&aR, &collisions);
70  setupDone = true;
71  }
72 }
73 
74 //----------------------------------------------------------------------------
75 
77 {
78  G4AutoLock l(&collisions_mutex);
79  std::for_each(collisions.begin(), collisions.end(), G4Delete());
80  collisions.clear();
81 }
82 
83 //----------------------------------------------------------------------------
84 
86  const G4KineticTrack& trk2) const
87 {
88  G4double time = DBL_MAX;
89  G4double distance_fast;
91 // G4cout << "zcomp=" << std::abs(mom1.vect().unit().z() -1 ) << G4endl;
92  G4double collisionTime;
93 
94  if ( std::abs(mom1.vect().unit().z() -1 ) < 1e-6 )
95  {
97  G4double deltaz=position.z();
98  G4double velocity = mom1.z()/mom1.e() * c_light;
99 
100  collisionTime=deltaz/velocity;
101  distance_fast=position.x()*position.x() + position.y()*position.y();
102  } else {
103 
104  // The nucleons of the nucleus are FROZEN, ie. do not move..
105 
106  G4ThreeVector position = trk2.GetPosition() - trk1.GetPosition();
107 
108  G4ThreeVector velocity = mom1.vect()/mom1.e() * c_light; // mom1.boostVector() will exit on slightly negative mass
109  collisionTime = (position * velocity) / velocity.mag2(); // can't divide by /c_light;
110  position -= velocity * collisionTime;
111  distance_fast=position.mag2();
112 
113 // if ( collisionTime>0 ) G4cout << " dis1/2 square" << dis1 <<" "<< dis2 << G4endl;
114 // collisionTime = GetTimeToClosestApproach(trk1,trk2);
115  }
116  if (collisionTime > 0)
117  {
118  static const G4double maxCrossSection = 500*millibarn;
119  if(0.7*pi*distance_fast>maxCrossSection) return time;
120 
121 
122  G4LorentzVector mom2(0,0,0,trk2.Get4Momentum().mag());
123 
124 // G4ThreeVector momLab = mom1.vect();// frozen Nucleus - mom2.vect();
125 // G4ThreeVector posLab = trk1.GetPosition() - trk2.GetPosition();
126 // G4double disLab=posLab * posLab - (posLab*momLab) * (posLab*momLab) /(momLab.mag2());
127 
128  G4LorentzRotation toCMSFrame((-1)*(mom1 + mom2).boostVector());
129  mom1 = toCMSFrame * mom1;
130  mom2 = toCMSFrame * mom2;
131 
132  G4LorentzVector coordinate1(trk1.GetPosition(), 100.);
133  G4LorentzVector coordinate2(trk2.GetPosition(), 100.);
134  G4ThreeVector pos = ((toCMSFrame * coordinate1).vect() -
135  (toCMSFrame * coordinate2).vect());
136 
137  G4ThreeVector mom = mom1.vect() - mom2.vect();
138 
139  // Calculate the impact parameter
140 
141  G4double distance = pos * pos - (pos*mom) * (pos*mom) / (mom.mag2());
142 
143 // G4cout << " disDiff " << distance-disLab << " " << disLab
144 // << " " << std::abs(distance-disLab)/distance << G4endl
145 // << " mom/Lab " << mom << " " << momLab << G4endl
146 // << " pos/Lab " << pos << " " << posLab
147 // << G4endl;
148 
149  if(pi*distance>maxCrossSection) return time;
150 
151  // charged particles special
152  static const G4double maxChargedCrossSection = 200*millibarn;
153  if(std::abs(trk1.GetDefinition()->GetPDGCharge())>0.1 &&
154  std::abs(trk2.GetDefinition()->GetPDGCharge())>0.1 &&
155  pi*distance>maxChargedCrossSection) return time;
156 
157  G4double sqrtS = (trk1.Get4Momentum() + trk2.Get4Momentum()).mag();
158  // neutrons special pn is largest cross-section, but above 1.91 GeV is less than 200 mb
159  if(( trk1.GetDefinition() == G4Neutron::Neutron() ||
160  trk2.GetDefinition() == G4Neutron::Neutron() ) &&
161  sqrtS>1.91*GeV && pi*distance>maxChargedCrossSection) return time;
162 
163 /*
164  * if(distance <= sqr(1.14*fermi))
165  * {
166  * time = collisionTime;
167  *
168  * *
169  * * G4cout << "Scatter distance/time: " << std::sqrt(distance)/fermi <<
170  * * " / "<< time/ns << G4endl;
171  * * G4ThreeVector pos1=trk1.GetPosition();
172  * * G4ThreeVector pos2=trk2.GetPosition();
173  * * G4LorentzVector xmom1 = trk1.Get4Momentum();
174  * * G4LorentzVector xmom2 = trk2.Get4Momentum();
175  * * G4cout << "position1: " << pos1.x() << " " << pos1.y() << " "
176  * * << pos1.z();
177  * * pos1+=(collisionTime*c_light/xmom1.e())*xmom1.vect();
178  * * G4cout << " straight line trprt: "
179  * * << pos1.x() << " " << pos1.y() << " "
180  * * << pos1.z() << G4endl;
181  * * G4cout << "position2: " << pos2.x() << " " << pos2.y() << " "
182  * * << pos2.z() << G4endl;
183  * * G4cout << "straight line distance 2 fixed:" << (pos1-pos2).mag()/fermi << G4endl;
184  * * pos2+= (collisionTime*c_light/xmom2.e())*xmom2.vect();
185  * * G4cout<< " straight line trprt: "
186  * * << pos2.x() << " " << pos2.y() << " "
187  * * << pos2.z() << G4endl;
188  * * G4cout << "straight line distance :" << (pos1-pos2).mag()/fermi << G4endl;
189  * *
190  * }
191  *
192  * if(1)
193  * return time;
194  */
195 
196  if ((trk1.GetActualMass()+trk2.GetActualMass()) > sqrtS) return time;
197 
198 
199 
200  const G4VCollision* collision = FindCollision(trk1,trk2);
201  G4double totalCrossSection;
202  // The cross section is interpreted geometrically as an area
203  // Two particles are assumed to collide if their distance is < (totalCrossSection/pi)
204 
205  if (collision != 0)
206  {
207  totalCrossSection = collision->CrossSection(trk1,trk2);
208  if ( totalCrossSection > 0 )
209  {
210 /* G4cout << " totalCrossection = "<< totalCrossSection << ", trk1/2, s, e-m: "
211  * << trk1.GetDefinition()->GetParticleName()
212  * << " / "
213  * << trk2.GetDefinition()->GetParticleName()
214  * << ", "
215  * << (trk1.Get4Momentum()+trk2.Get4Momentum()).mag()
216  * << ", "
217  * << (trk1.Get4Momentum()+trk2.Get4Momentum()).mag()-
218  * trk1.Get4Momentum().mag() - trk2.Get4Momentum().mag()
219  * << G4endl;
220  */
221  if (distance <= totalCrossSection / pi)
222  {
223  time = collisionTime;
224  }
225  } else
226  {
227 
228  // For debugging...
229  // G4cout << " totalCrossection = 0, trk1/2, s, e-m: "
230  // << trk1.GetDefinition()->GetParticleName()
231  // << " / "
232  // << trk2.GetDefinition()->GetParticleName()
233  // << ", "
234  // << (trk1.Get4Momentum()+trk2.Get4Momentum()).mag()
235  // << ", "
236  // << (trk1.Get4Momentum()+trk2.Get4Momentum()).mag()-
237  // trk1.Get4Momentum().mag() - trk2.Get4Momentum().mag()
238  // << G4endl;
239 
240  }
241 /*
242  * if(distance <= sqr(5.*fermi))
243  * {
244  * G4cout << " distance,xsect, std::sqrt(xsect/pi) : " << std::sqrt(distance)/fermi
245  * << " " << totalCrossSection/sqr(fermi)
246  * << " " << std::sqrt(totalCrossSection / pi)/fermi << G4endl;
247  * }
248  */
249 
250  }
251  else
252  {
253  time = DBL_MAX;
254 // /*
255  // For debugging
256 //hpw G4cout << "G4Scatterer - collision not found: "
257 //hpw << trk1.GetDefinition()->GetParticleName()
258 //hpw << " - "
259 //hpw << trk2.GetDefinition()->GetParticleName()
260 //hpw << G4endl;
261  // End of debugging
262 // */
263  }
264  }
265 
266  else
267  {
268  /*
269  // For debugging
270  G4cout << "G4Scatterer - negative collisionTime"
271  << ": collisionTime = " << collisionTime
272  << ", position = " << position
273  << ", velocity = " << velocity
274  << G4endl;
275  // End of debugging
276  */
277  }
278 
279  return time;
280 }
281 
282 //----------------------------------------------------------------------------
283 
285  const G4KineticTrack& trk2) const
286 {
287 // G4double sqrtS = (trk1.Get4Momentum() + trk2.Get4Momentum()).mag();
288  G4LorentzVector pInitial=trk1.Get4Momentum() + trk2.Get4Momentum();
289  G4double energyBalance = pInitial.t();
290  G4double pxBalance = pInitial.vect().x();
291  G4double pyBalance = pInitial.vect().y();
292  G4double pzBalance = pInitial.vect().z();
293  G4int chargeBalance = G4lrint(trk1.GetDefinition()->GetPDGCharge()
294  + trk2.GetDefinition()->GetPDGCharge());
295  G4int baryonBalance = trk1.GetDefinition()->GetBaryonNumber()
296  + trk2.GetDefinition()->GetBaryonNumber();
297 
298  const G4VCollision* collision = FindCollision(trk1,trk2);
299  if (collision != 0)
300  {
301  G4double aCrossSection = collision->CrossSection(trk1,trk2);
302  if (aCrossSection > 0.0)
303  {
304 
305 
306  #ifdef debug_G4Scatterer
307  G4cout << "be4 FinalState 1(p,e,m): "
308  << trk1.Get4Momentum() << " "
309  << trk1.Get4Momentum().mag()
310  << ", 2: "
311  << trk2.Get4Momentum()<< " "
312  << trk2.Get4Momentum().mag() << " "
313  << G4endl;
314  #endif
315 
316 
317  G4KineticTrackVector* products = collision->FinalState(trk1,trk2);
318  if(!products || products->size() == 0) return products;
319 
320  #ifdef debug_G4Scatterer
321  G4cout << "size of FS: "<<products->size()<<G4endl;
322  #endif
323 
324  G4KineticTrack *final= products->operator[](0);
325 
326 
327  #ifdef debug_G4Scatterer
328  G4cout << " FinalState 1: "
329  << final->Get4Momentum()<< " "
330  << final->Get4Momentum().mag() ;
331  #endif
332 
333  if(products->size() == 1) return products;
334  final=products->operator[](1);
335  #ifdef debug_G4Scatterer
336  G4cout << ", 2: "
337  << final->Get4Momentum() << " "
338  << final->Get4Momentum().mag() << " " << G4endl;
339  #endif
340 
341  final= products->operator[](0);
342  G4LorentzVector pFinal=final->Get4Momentum();
343  if(products->size()==2)
344  {
345  final=products->operator[](1);
346  pFinal +=final->Get4Momentum();
347  }
348 
349  #ifdef debug_G4Scatterer
350  if ( (pInitial-pFinal).mag() > 0.1*MeV )
351  {
352  G4cout << "G4Scatterer: momentum imbalance, pInitial= " <<pInitial << " pFinal= " <<pFinal<< G4endl;
353  }
354  G4cout << "Scatterer costh= " << trk1.Get4Momentum().vect().unit() *(products->operator[](0))->Get4Momentum().vect().unit()<< G4endl;
355  #endif
356 
357  for(size_t hpw=0; hpw<products->size(); hpw++)
358  {
359  energyBalance-=products->operator[](hpw)->Get4Momentum().t();
360  pxBalance-=products->operator[](hpw)->Get4Momentum().vect().x();
361  pyBalance-=products->operator[](hpw)->Get4Momentum().vect().y();
362  pzBalance-=products->operator[](hpw)->Get4Momentum().vect().z();
363  chargeBalance-=G4lrint(products->operator[](hpw)->GetDefinition()->GetPDGCharge());
364  baryonBalance-=products->operator[](hpw)->GetDefinition()->GetBaryonNumber();
365  }
366  if(getenv("ScattererEnergyBalanceCheck"))
367  std::cout << "DEBUGGING energy balance A: "
368  <<energyBalance<<" "
369  <<pxBalance<<" "
370  <<pyBalance<<" "
371  <<pzBalance<<" "
372  <<chargeBalance<<" "
373  <<baryonBalance<<" "
374  <<G4endl;
375  if(chargeBalance !=0 )
376  {
377  G4cout << "track 1"<<trk1.GetDefinition()->GetParticleName()<<G4endl;
378  G4cout << "track 2"<<trk2.GetDefinition()->GetParticleName()<<G4endl;
379  for(size_t hpw=0; hpw<products->size(); hpw++)
380  {
381  G4cout << products->operator[](hpw)->GetDefinition()->GetParticleName()<<G4endl;
382  }
383  G4Exception("G4Scatterer", "im_r_matrix001", FatalException,
384  "Problem in ChargeBalance");
385  }
386  return products;
387  }
388  }
389 
390  return NULL;
391 }
392 
393 //----------------------------------------------------------------------------
394 
395 const G4VCollision* G4Scatterer::FindCollision(const G4KineticTrack& trk1,
396  const G4KineticTrack& trk2) const
397 {
398  G4VCollision* collisionInCharge = 0;
399 
400  size_t i;
401  for (i=0; i<collisions.size(); i++)
402  {
403  G4VCollision* component = collisions[i];
404  if (component->IsInCharge(trk1,trk2))
405  {
406  collisionInCharge = component;
407  break;
408  }
409  }
410 // if(collisionInCharge)
411 // {
412 // G4cout << "found collision : "
413 // << collisionInCharge->GetName()<< " "
414 // << "for "
415 // << trk1.GetDefinition()->GetParticleName()<<" + "
416 // << trk2.GetDefinition()->GetParticleName()<<" "
417 // << G4endl;;
418 // }
419  return collisionInCharge;
420 }
421 
422 //----------------------------------------------------------------------------
423 
425  const G4KineticTrack& trk2) const
426 {
427  const G4VCollision* collision = FindCollision(trk1,trk2);
428  G4double aCrossSection = 0;
429  if (collision != 0)
430  {
431  aCrossSection = collision->CrossSection(trk1,trk2);
432  }
433  return aCrossSection;
434 }
435 
436 //----------------------------------------------------------------------------
437 
438 const std::vector<G4CollisionInitialState *> & G4Scatterer::
440  std::vector<G4KineticTrack *> & someCandidates,
441  G4double aCurrentTime)
442 {
443  theCollisions.clear();
444  std::vector<G4KineticTrack *>::iterator j=someCandidates.begin();
445  for(; j != someCandidates.end(); ++j)
446  {
447  G4double collisionTime = GetTimeToInteraction(*aProjectile, **j);
448  if(collisionTime == DBL_MAX) // no collision
449  {
450  continue;
451  }
452  G4KineticTrackVector aTarget;
453  aTarget.push_back(*j);
454  theCollisions.push_back(
455  new G4CollisionInitialState(collisionTime+aCurrentTime, aProjectile, aTarget, this) );
456 // G4cerr <<" !!!!!! debug collisions "<<collisionTime<<" "<<pkt->GetDefinition()->GetParticleName()<<G4endl;
457  }
458  return theCollisions;
459 }
460 
461 
464  std::vector<G4KineticTrack *> & theTargets)
465 {
466  G4KineticTrack target_reloc(*(theTargets[0]));
467  return Scatter(*aProjectile, target_reloc);
468 }
469 //----------------------------------------------------------------------------
virtual G4bool IsInCharge(const G4KineticTrack &trk1, const G4KineticTrack &trk2) const =0
static void Apply()
Definition: G4Pair.hh:179
double x() const
virtual G4double GetTimeToInteraction(const G4KineticTrack &trk1, const G4KineticTrack &trk2) const
Definition: G4Scatterer.cc:85
const G4ThreeVector & GetPosition() const
G4double GetActualMass() const
int G4int
Definition: G4Types.hh:78
#define G4MUTEX_INITIALIZER
Definition: G4Threading.hh:175
const G4String & GetParticleName() const
double z() const
virtual const std::vector< G4CollisionInitialState * > & GetCollisions(G4KineticTrack *aProjectile, std::vector< G4KineticTrack * > &someCandidates, G4double aCurrentTime)
Definition: G4Scatterer.cc:439
void Register(T *inst)
Definition: G4AutoDelete.hh:65
Hep3Vector vect() const
G4GLOB_DLL std::ostream G4cout
double mag() const
bool G4bool
Definition: G4Types.hh:79
virtual G4double CrossSection(const G4KineticTrack &trk1, const G4KineticTrack &trk2) const
Definition: G4VCollision.cc:55
std::vector< G4VCollision * > G4CollisionVector
static G4Neutron * Neutron()
Definition: G4Neutron.cc:104
void G4Exception(const char *originOfException, const char *exceptionCode, G4ExceptionSeverity severity, const char *comments)
Definition: G4Exception.cc:41
G4int G4Mutex
Definition: G4Threading.hh:173
int G4lrint(double ad)
Definition: templates.hh:163
virtual G4KineticTrackVector * Scatter(const G4KineticTrack &trk1, const G4KineticTrack &trk2) const
Definition: G4Scatterer.cc:284
const G4LorentzVector & GetTrackingMomentum() const
Hep3Vector unit() const
double y() const
#define GROUP2(t1, t2)
Definition: G4Pair.hh:42
static constexpr double GeV
Definition: G4SIunits.hh:217
double mag2() const
virtual G4KineticTrackVector * FinalState(const G4KineticTrack &trk1, const G4KineticTrack &trk2) const =0
G4double GetCrossSection(const G4KineticTrack &trk1, const G4KineticTrack &trk2) const
Definition: G4Scatterer.cc:424
virtual ~G4Scatterer()
Definition: G4Scatterer.cc:76
#define G4endl
Definition: G4ios.hh:61
static constexpr double MeV
Definition: G4SIunits.hh:214
static constexpr double pi
Definition: G4SIunits.hh:75
double G4double
Definition: G4Types.hh:76
virtual G4KineticTrackVector * GetFinalState(G4KineticTrack *aProjectile, std::vector< G4KineticTrack * > &theTargets)
Definition: G4Scatterer.cc:463
G4double GetPDGCharge() const
const G4LorentzVector & Get4Momentum() const
#define DBL_MAX
Definition: templates.hh:83
const G4ParticleDefinition * GetDefinition() const
float c_light
Definition: hepunit.py:257
static const G4double pos
static constexpr double millibarn
Definition: G4SIunits.hh:106