Geant4  10.00.p03
G4LEpp.cc
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26 
27  // G4 Low energy model: n-n or p-p scattering
28  // F.W. Jones, L.G. Greeniaus, H.P. Wellisch
29 
30 // FWJ 27-AUG-2010: extended Coulomb-suppressed data to 5 GeV
31 
32 #include "G4LEpp.hh"
33 #include "G4PhysicalConstants.hh"
34 #include "G4SystemOfUnits.hh"
35 #include "Randomize.hh"
36 #include "G4ios.hh"
37 
38 // Initialization of static data arrays:
39 #include "G4LEppData.hh"
40 
42 {
43  // theParticleChange.SetNumberOfSecondaries(1);
44  // SetMinEnergy(10.*MeV);
45  // SetMaxEnergy(1200.*MeV);
46 
48 
49  SetMinEnergy(0.);
50  SetMaxEnergy(5.*GeV);
51 }
52 
54 {
55  // theParticleChange.Clear();
56 }
57 
58 
59 void
61 {
62  if (State) {
63  for(G4int i=0; i<NANGLE; i++)
64  {
65  sig[i] = SigCoul[i];
66  }
67  elab = ElabCoul;
68  SetMaxEnergy(1.2*GeV);
69  }
70  else {
71  for(G4int i=0; i<NANGLE; i++)
72  {
73  sig[i] = Sig[i];
74  }
75  elab = Elab;
76  SetMaxEnergy(5.*GeV);
77  }
78 }
79 
80 
82 G4LEpp::ApplyYourself(const G4HadProjectile& aTrack, G4Nucleus& targetNucleus)
83 {
85  const G4HadProjectile* aParticle = &aTrack;
86 
87  G4double P = aParticle->GetTotalMomentum();
88  G4double Px = aParticle->Get4Momentum().x();
89  G4double Py = aParticle->Get4Momentum().y();
90  G4double Pz = aParticle->Get4Momentum().z();
91  G4double ek = aParticle->GetKineticEnergy();
92  G4ThreeVector theInitial = aParticle->Get4Momentum().vect();
93 
94  if (verboseLevel > 1) {
95  G4double E = aParticle->GetTotalEnergy();
96  G4double E0 = aParticle->GetDefinition()->GetPDGMass();
97  G4double Q = aParticle->GetDefinition()->GetPDGCharge();
98  G4int A = targetNucleus.GetA_asInt();
99  G4int Z = targetNucleus.GetZ_asInt();
100  G4cout << "G4LEpp:ApplyYourself: incident particle: "
101  << aParticle->GetDefinition()->GetParticleName() << G4endl;
102  G4cout << "P = " << P/GeV << " GeV/c"
103  << ", Px = " << Px/GeV << " GeV/c"
104  << ", Py = " << Py/GeV << " GeV/c"
105  << ", Pz = " << Pz/GeV << " GeV/c" << G4endl;
106  G4cout << "E = " << E/GeV << " GeV"
107  << ", kinetic energy = " << ek/GeV << " GeV"
108  << ", mass = " << E0/GeV << " GeV"
109  << ", charge = " << Q << G4endl;
110  G4cout << "G4LEpp:ApplyYourself: material:" << G4endl;
111  G4cout << "A = " << A
112  << ", Z = " << Z
113  << ", atomic mass "
114  << G4Proton::Proton()->GetPDGMass()/GeV << "GeV"
115  << G4endl;
116  //
117  // GHEISHA ADD operation to get total energy, mass, charge
118  //
119  E += proton_mass_c2;
120  G4double E02 = E*E - P*P;
121  E0 = std::sqrt(std::fabs(E02));
122  if (E02 < 0)E0 *= -1;
123  Q += Z;
124  G4cout << "G4LEpp:ApplyYourself: total:" << G4endl;
125  G4cout << "E = " << E/GeV << " GeV"
126  << ", mass = " << E0/GeV << " GeV"
127  << ", charge = " << Q << G4endl;
128  }
129 
130  // Find energy bin
131 
132  G4int je1 = 0;
133  G4int je2 = NENERGY - 1;
134  ek = ek/GeV;
135  do {
136  G4int midBin = (je1 + je2)/2;
137  if (ek < elab[midBin])
138  je2 = midBin;
139  else
140  je1 = midBin;
141  } while (je2 - je1 > 1);
142  G4double delab = elab[je2] - elab[je1];
143 
144  // Sample the angle
145 
146  G4float sample = G4UniformRand();
147  G4int ke1 = 0;
148  G4int ke2 = NANGLE - 1;
149  G4double dsig = sig[je2][0] - sig[je1][0];
150  G4double rc = dsig/delab;
151  G4double b = sig[je1][0] - rc*elab[je1];
152  G4double sigint1 = rc*ek + b;
153  G4double sigint2 = 0.;
154 
155  if (verboseLevel > 1) G4cout << "sample=" << sample << G4endl
156  << ke1 << " " << ke2 << " "
157  << sigint1 << " " << sigint2 << G4endl;
158 
159  do {
160  G4int midBin = (ke1 + ke2)/2;
161  dsig = sig[je2][midBin] - sig[je1][midBin];
162  rc = dsig/delab;
163  b = sig[je1][midBin] - rc*elab[je1];
164  G4double sigint = rc*ek + b;
165  if (sample < sigint) {
166  ke2 = midBin;
167  sigint2 = sigint;
168  }
169  else {
170  ke1 = midBin;
171  sigint1 = sigint;
172  }
173  if (verboseLevel > 1)G4cout << ke1 << " " << ke2 << " "
174  << sigint1 << " " << sigint2 << G4endl;
175  } while (ke2 - ke1 > 1);
176 
177  dsig = sigint2 - sigint1;
178  rc = 1./dsig;
179  b = ke1 - rc*sigint1;
180  G4double kint = rc*sample + b;
181  G4double theta = (0.5 + kint)*pi/180.;
182  if (theta < 0.) { theta = 0.; }
183 
184  if (verboseLevel > 1) {
185  G4cout << " energy bin " << je1 << " energy=" << elab[je1] << G4endl;
186  G4cout << " angle bin " << kint << " angle=" << theta/degree << G4endl;
187  }
188 
189  // Get the target particle
190  G4DynamicParticle* targetParticle = targetNucleus.ReturnTargetParticle();
191 
192  G4double E1 = aParticle->GetTotalEnergy();
193  G4double M1 = aParticle->GetDefinition()->GetPDGMass();
194  G4double E2 = targetParticle->GetTotalEnergy();
195  G4double M2 = targetParticle->GetDefinition()->GetPDGMass();
196  G4double totalEnergy = E1 + E2;
197  G4double pseudoMass = std::sqrt(totalEnergy*totalEnergy - P*P);
198 
199  // Transform into centre of mass system
200 
201  G4double px = (M2/pseudoMass)*Px;
202  G4double py = (M2/pseudoMass)*Py;
203  G4double pz = (M2/pseudoMass)*Pz;
204  G4double p = std::sqrt(px*px + py*py + pz*pz);
205 
206  if (verboseLevel > 1) {
207  G4cout << " E1, M1 (GeV) " << E1/GeV << " " << M1/GeV << G4endl;
208  G4cout << " E2, M2 (GeV) " << E2/GeV << " " << M2/GeV << G4endl;
209  G4cout << " particle 1 momentum in CM " << px/GeV << " " << py/GeV << " "
210  << pz/GeV << " " << p/GeV << G4endl;
211  }
212 
213  // First scatter w.r.t. Z axis
214  G4double phi = G4UniformRand()*twopi;
215  G4double pxnew = p*std::sin(theta)*std::cos(phi);
216  G4double pynew = p*std::sin(theta)*std::sin(phi);
217  G4double pznew = p*std::cos(theta);
218 
219  // Rotate according to the direction of the incident particle
220  if (px*px + py*py > 0) {
221  G4double cost, sint, ph, cosp, sinp;
222  cost = pz/p;
223  sint = (std::sqrt(std::fabs((1-cost)*(1+cost))) + std::sqrt(px*px+py*py)/p)/2;
224  py < 0 ? ph = 3*halfpi : ph = halfpi;
225  if (std::fabs(px) > 0.000001*GeV) ph = std::atan2(py,px);
226  cosp = std::cos(ph);
227  sinp = std::sin(ph);
228  px = (cost*cosp*pxnew - sinp*pynew + sint*cosp*pznew);
229  py = (cost*sinp*pxnew + cosp*pynew + sint*sinp*pznew);
230  pz = (-sint*pxnew + cost*pznew);
231  }
232  else {
233  px = pxnew;
234  py = pynew;
235  pz = pznew;
236  }
237 
238  if (verboseLevel > 1) {
239  G4cout << " AFTER SCATTER..." << G4endl;
240  G4cout << " particle 1 momentum in CM " << px/GeV << " " << py/GeV << " "
241  << pz/GeV << " " << p/GeV << G4endl;
242  }
243 
244  // Transform to lab system
245 
246  G4double E1pM2 = E1 + M2;
247  G4double betaCM = P/E1pM2;
248  G4double betaCMx = Px/E1pM2;
249  G4double betaCMy = Py/E1pM2;
250  G4double betaCMz = Pz/E1pM2;
251  G4double gammaCM = E1pM2/std::sqrt(E1pM2*E1pM2 - P*P);
252 
253  if (verboseLevel > 1) {
254  G4cout << " betaCM " << betaCMx << " " << betaCMy << " "
255  << betaCMz << " " << betaCM << G4endl;
256  G4cout << " gammaCM " << gammaCM << G4endl;
257  }
258 
259  // Now following GLOREN...
260 
261  G4double BETA[5], PA[5], PB[5];
262  BETA[1] = -betaCMx;
263  BETA[2] = -betaCMy;
264  BETA[3] = -betaCMz;
265  BETA[4] = gammaCM;
266 
267  //The incident particle...
268 
269  PA[1] = px;
270  PA[2] = py;
271  PA[3] = pz;
272  PA[4] = std::sqrt(M1*M1 + p*p);
273 
274  G4double BETPA = BETA[1]*PA[1] + BETA[2]*PA[2] + BETA[3]*PA[3];
275  G4double BPGAM = (BETPA * BETA[4]/(BETA[4] + 1.) - PA[4]) * BETA[4];
276 
277  PB[1] = PA[1] + BPGAM * BETA[1];
278  PB[2] = PA[2] + BPGAM * BETA[2];
279  PB[3] = PA[3] + BPGAM * BETA[3];
280  PB[4] = (PA[4] - BETPA) * BETA[4];
281 
283  newP->SetDefinition(const_cast<G4ParticleDefinition *>(aParticle->GetDefinition()) );
284  newP->SetMomentum(G4ThreeVector(PB[1], PB[2], PB[3]));
285 
286  //The target particle...
287 
288  PA[1] = -px;
289  PA[2] = -py;
290  PA[3] = -pz;
291  PA[4] = std::sqrt(M2*M2 + p*p);
292 
293  BETPA = BETA[1]*PA[1] + BETA[2]*PA[2] + BETA[3]*PA[3];
294  BPGAM = (BETPA * BETA[4]/(BETA[4] + 1.) - PA[4]) * BETA[4];
295 
296  PB[1] = PA[1] + BPGAM * BETA[1];
297  PB[2] = PA[2] + BPGAM * BETA[2];
298  PB[3] = PA[3] + BPGAM * BETA[3];
299  PB[4] = (PA[4] - BETPA) * BETA[4];
300 
301  targetParticle->SetMomentum(G4ThreeVector(PB[1], PB[2], PB[3]));
302 
303  if (verboseLevel > 1) {
304  G4cout << " particle 1 momentum in LAB "
305  << newP->GetMomentum()/GeV
306  << " " << newP->GetTotalMomentum()/GeV << G4endl;
307  G4cout << " particle 2 momentum in LAB "
308  << targetParticle->GetMomentum()/GeV
309  << " " << targetParticle->GetTotalMomentum()/GeV << G4endl;
310  G4cout << " TOTAL momentum in LAB "
311  << (newP->GetMomentum()+targetParticle->GetMomentum())/GeV
312  << " "
313  << (newP->GetMomentum()+targetParticle->GetMomentum()).mag()/GeV
314  << G4endl;
315  }
316 
319  delete newP;
320 
321  // Recoil particle
322  theParticleChange.AddSecondary(targetParticle);
323  return &theParticleChange;
324 }
325 
326  // end of file
G4int GetA_asInt() const
Definition: G4Nucleus.hh:109
static const G4float Sig[NENERGY][NANGLE]
Definition: G4LEpp.hh:76
void SetMomentum(const G4ThreeVector &momentum)
G4double GetKineticEnergy() const
const G4float * elab
Definition: G4LEpp.hh:70
G4LEpp()
Definition: G4LEpp.cc:41
CLHEP::Hep3Vector G4ThreeVector
G4double GetTotalEnergy() const
static const G4float SigCoul[NENERGYC][NANGLE]
Definition: G4LEpp.hh:81
~G4LEpp()
Definition: G4LEpp.cc:53
G4HadFinalState * ApplyYourself(const G4HadProjectile &aTrack, G4Nucleus &targetNucleus)
Definition: G4LEpp.cc:82
const G4double pi
float G4float
Definition: G4Types.hh:77
G4ParticleDefinition * GetDefinition() const
#define State(theXInfo)
int G4int
Definition: G4Types.hh:78
G4DynamicParticle * ReturnTargetParticle() const
Definition: G4Nucleus.cc:227
const G4String & GetParticleName() const
void SetCoulombEffects(G4int State)
Definition: G4LEpp.cc:60
G4double GetTotalMomentum() const
void SetMinEnergy(G4double anEnergy)
static const G4float Elab[NENERGY]
Definition: G4LEpp.hh:77
#define G4UniformRand()
Definition: Randomize.hh:87
G4GLOB_DLL std::ostream G4cout
const G4ParticleDefinition * GetDefinition() const
const G4ThreeVector & GetMomentumDirection() const
G4double GetKineticEnergy() const
static G4Proton * Proton()
Definition: G4Proton.cc:93
static const double GeV
Definition: G4SIunits.hh:196
static const G4float ElabCoul[NENERGYC]
Definition: G4LEpp.hh:82
static const G4double A[nN]
const G4LorentzVector & Get4Momentum() const
void SetEnergyChange(G4double anEnergy)
G4double GetPDGMass() const
G4int GetZ_asInt() const
Definition: G4Nucleus.hh:115
static const double degree
Definition: G4SIunits.hh:125
void SetMaxEnergy(const G4double anEnergy)
#define G4endl
Definition: G4ios.hh:61
double G4double
Definition: G4Types.hh:76
void SetDefinition(const G4ParticleDefinition *aParticleDefinition)
G4double GetPDGCharge() const
void SetMomentumChange(const G4ThreeVector &aV)
void AddSecondary(G4DynamicParticle *aP)
G4ThreeVector GetMomentum() const
G4double GetTotalMomentum() const
G4double GetTotalEnergy() const
const G4float * sig[NANGLE]
Definition: G4LEpp.hh:69