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G4NonEquilibriumEvaporator.cc
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26 // $Id$
27 //
28 // 20100114 M. Kelsey -- Remove G4CascadeMomentum, use G4LorentzVector directly
29 // 20100309 M. Kelsey -- Use new generateWithRandomAngles for theta,phi stuff;
30 // eliminate some unnecessary std::pow()
31 // 20100412 M. Kelsey -- Pass G4CollisionOutput by ref to ::collide()
32 // 20100413 M. Kelsey -- Pass buffers to paraMaker[Truncated]
33 // 20100517 M. Kelsey -- Inherit from common base class
34 // 20100617 M. Kelsey -- Remove "RUN" preprocessor flag and all "#else" code
35 // 20100622 M. Kelsey -- Use local "bindingEnergy()" function to call through.
36 // 20100701 M. Kelsey -- Don't need to add excitation to nuclear mass; compute
37 // new excitation energies properly (mass differences)
38 // 20100713 M. Kelsey -- Add conservation checking, diagnostic messages.
39 // 20100714 M. Kelsey -- Move conservation checking to base class
40 // 20100719 M. Kelsey -- Simplify EEXS calculations with particle evaporation.
41 // 20100724 M. Kelsey -- Replace std::vector<> D with trivial D[3] array.
42 // 20100914 M. Kelsey -- Migrate to integer A and Z: this involves replacing
43 // a number of G4double terms with G4int, with consequent casts.
44 // 20110214 M. Kelsey -- Follow G4InuclParticle::Model enumerator migration
45 // 20110922 M. Kelsey -- Follow G4InuclParticle::print(ostream&) migration
46 // 20120608 M. Kelsey -- Fix variable-name "shadowing" compiler warnings.
47 // 20121009 M. Kelsey -- Add some high-verbosity debugging output
48 
49 #include <cmath>
50 
51 #include "G4NonEquilibriumEvaporator.hh"
52 #include "G4SystemOfUnits.hh"
53 #include "G4CollisionOutput.hh"
54 #include "G4InuclElementaryParticle.hh"
55 #include "G4InuclNuclei.hh"
56 #include "G4InuclSpecialFunctions.hh"
57 #include "G4LorentzConvertor.hh"
58 
59 using namespace G4InuclSpecialFunctions;
60 
61 
62 G4NonEquilibriumEvaporator::G4NonEquilibriumEvaporator()
63  : G4CascadeColliderBase("G4NonEquilibriumEvaporator") {}
64 
65 
66 void G4NonEquilibriumEvaporator::collide(G4InuclParticle* /*bullet*/,
67  G4InuclParticle* target,
68  G4CollisionOutput& output) {
69 
70  if (verboseLevel) {
71  G4cout << " >>> G4NonEquilibriumEvaporator::collide" << G4endl;
72  }
73 
74  // Sanity check
75  G4InuclNuclei* nuclei_target = dynamic_cast<G4InuclNuclei*>(target);
76  if (!nuclei_target) {
77  G4cerr << " NonEquilibriumEvaporator -> target is not nuclei " << G4endl;
78  return;
79  }
80 
81  if (verboseLevel > 2) G4cout << " evaporating target:\n" << *target << G4endl;
82 
83  const G4int a_cut = 5;
84  const G4int z_cut = 3;
85 
86  const G4double eexs_cut = 0.1;
87 
88  const G4double coul_coeff = 1.4;
89  const G4int itry_max = 1000;
90  const G4double small_ekin = 1.0e-6;
91  const G4double width_cut = 0.005;
92 
93  G4int A = nuclei_target->getA();
94  G4int Z = nuclei_target->getZ();
95 
96  G4LorentzVector PEX = nuclei_target->getMomentum();
97  G4LorentzVector pin = PEX; // Save original four-vector for later
98 
99  G4double EEXS = nuclei_target->getExitationEnergy();
100 
101  G4ExitonConfiguration config = nuclei_target->getExitonConfiguration();
102 
103  G4int QPP = config.protonQuasiParticles;
104  G4int QNP = config.neutronQuasiParticles;
105  G4int QPH = config.protonHoles;
106  G4int QNH = config.neutronHoles;
107 
108  G4int QP = QPP + QNP;
109  G4int QH = QPH + QNH;
110  G4int QEX = QP + QH;
111 
112  G4InuclElementaryParticle dummy(small_ekin, 1);
113  G4LorentzConvertor toTheExitonSystemRestFrame;
114  //*** toTheExitonSystemRestFrame.setVerbose(verboseLevel);
115  toTheExitonSystemRestFrame.setBullet(dummy);
116 
117  G4double EFN = FermiEnergy(A, Z, 0);
118  G4double EFP = FermiEnergy(A, Z, 1);
119 
120  G4int AR = A - QP;
121  G4int ZR = Z - QPP;
122  G4int NEX = QEX;
123  G4LorentzVector ppout;
124  G4bool try_again = (NEX > 0);
125 
126  // Buffer for parameter sets
127  std::pair<G4double, G4double> parms;
128 
129  while (try_again) {
130  if (A >= a_cut && Z >= z_cut && EEXS > eexs_cut) { // ok
131  // update exiton system (include excitation energy!)
132  G4double nuc_mass = G4InuclNuclei::getNucleiMass(A, Z, EEXS);
133  PEX.setVectM(PEX.vect(), nuc_mass);
134  toTheExitonSystemRestFrame.setTarget(PEX);
135  toTheExitonSystemRestFrame.toTheTargetRestFrame();
136 
137  if (verboseLevel > 2) {
138  G4cout << " A " << A << " Z " << Z << " mass " << nuc_mass
139  << " EEXS " << EEXS << G4endl;
140  }
141 
142  G4double MEL = getMatrixElement(A);
143  G4double E0 = getE0(A);
144  G4double PL = getParLev(A, Z);
145  G4double parlev = PL / A;
146  G4double EG = PL * EEXS;
147 
148  if (QEX < std::sqrt(2.0 * EG)) { // ok
149  if (verboseLevel > 3)
150  G4cout << " QEX " << QEX << " < sqrt(2*EG) " << std::sqrt(2.*EG)
151  << " NEX " << NEX << G4endl;
152 
153  paraMakerTruncated(Z, parms);
154  const G4double& AK1 = parms.first;
155  const G4double& CPA1 = parms.second;
156 
157  G4double VP = coul_coeff * Z * AK1 / (G4cbrt(A-1) + 1.0) /
158  (1.0 + EEXS / E0);
159  G4double DM1 = bindingEnergy(A,Z);
160  G4double BN = DM1 - bindingEnergy(A-1,Z);
161  G4double BP = DM1 - bindingEnergy(A-1,Z-1);
162  G4double EMN = EEXS - BN;
163  G4double EMP = EEXS - BP - VP * A / (A-1);
164  G4double ESP = 0.0;
165 
166  if (verboseLevel > 3) {
167  G4cout << " AK1 " << AK1 << " CPA1 " << " VP " << VP
168  << "\n bind(A,Z) " << DM1 << " dBind(N) " << BN
169  << " dBind(P) " << BP
170  << "\n EMN " << EMN << " EMP " << EMP << G4endl;
171  }
172 
173  if (EMN > eexs_cut) { // ok
174  G4int icase = 0;
175 
176  if (NEX > 1) {
177  G4double APH = 0.25 * (QP * QP + QH * QH + QP - 3 * QH);
178  G4double APH1 = APH + 0.5 * (QP + QH);
179  ESP = EEXS / QEX;
180  G4double MELE = MEL / ESP / (A*A*A);
181 
182  if (verboseLevel > 3)
183  G4cout << " APH " << APH << " APH1 " << APH1 << " ESP " << ESP
184  << G4endl;
185 
186  if (ESP > 15.0) {
187  MELE *= std::sqrt(15.0 / ESP);
188  } else if(ESP < 7.0) {
189  MELE *= std::sqrt(ESP / 7.0);
190  if (ESP < 2.0) MELE *= std::sqrt(ESP / 2.0);
191  };
192 
193  G4double F1 = EG - APH;
194  G4double F2 = EG - APH1;
195 
196  if (verboseLevel > 3)
197  G4cout << " MELE " << MELE << " F1 " << F1 << " F2 " << F2
198  << G4endl;
199 
200  if (F1 > 0.0 && F2 > 0.0) {
201  G4double F = F2 / F1;
202  G4double M1 = 2.77 * MELE * PL;
203  G4double D[3] = { 0., 0., 0. };
204  D[0] = M1 * F2 * F2 * std::pow(F, NEX-1) / (QEX+1);
205 
206  if (D[0] > 0.0) {
207 
208  if (NEX >= 2) {
209  D[1] = 0.0462 / parlev / G4cbrt(A) * QP * EEXS / QEX;
210 
211  if (EMP > eexs_cut)
212  D[2] = D[1] * std::pow(EMP / EEXS, NEX) * (1.0 + CPA1);
213  D[1] *= std::pow(EMN / EEXS, NEX) * getAL(A);
214 
215  if (QNP < 1) D[1] = 0.0;
216  if (QPP < 1) D[2] = 0.0;
217 
218  try_again = NEX > 1 && (D[1] > width_cut * D[0] ||
219  D[2] > width_cut * D[0]);
220 
221  if (try_again) {
222  G4double D5 = D[0] + D[1] + D[2];
223  G4double SL = D5 * inuclRndm();
224  G4double S1 = 0.;
225 
226  if (verboseLevel > 3)
227  G4cout << " D5 " << D5 << " SL " << SL << G4endl;
228 
229  for (G4int i = 0; i < 3; i++) {
230  S1 += D[i];
231  if (SL <= S1) {
232  icase = i;
233  break;
234  }
235  }
236 
237  if (verboseLevel > 3)
238  G4cout << " got icase " << icase << G4endl;
239  } // if (try_again)
240  } // if (NEX >= 2)
241  } else try_again = false; // if (D[0] > 0)
242  } else try_again = false; // if (F1>0 && F2>0)
243  } // if (NEX > 1)
244 
245  if (try_again) {
246  if (icase > 0) { // N -> N-1 with particle escape
247  if (verboseLevel > 3)
248  G4cout << " try_again icase " << icase << G4endl;
249 
250  G4double V = 0.0;
251  G4int ptype = 0;
252  G4double B = 0.0;
253 
254  if (A < 3.0) try_again = false;
255 
256  if (try_again) {
257 
258  if (icase == 1) { // neutron escape
259  if (verboseLevel > 3)
260  G4cout << " trying neutron escape" << G4endl;
261 
262  if (QNP < 1) icase = 0;
263  else {
264  B = BN;
265  V = 0.0;
266  ptype = 2;
267  };
268  } else { // proton esape
269  if (verboseLevel > 3)
270  G4cout << " trying proton escape" << G4endl;
271 
272  if (QPP < 1) icase = 0;
273  else {
274  B = BP;
275  V = VP;
276  ptype = 1;
277 
278  if (Z-1 < 1) try_again = false;
279  };
280  };
281 
282  if (try_again && icase != 0) {
283  if (verboseLevel > 3)
284  G4cout << " ptype " << ptype << " B " << B << " V " << V
285  << G4endl;
286 
287  G4double EB = EEXS - B;
288  G4double E = EB - V * A / (A-1);
289 
290  if (E < 0.0) icase = 0;
291  else {
292  G4double E1 = EB - V;
293  G4double EEXS_new = -1.;
294  G4double EPART = 0.0;
295  G4int itry1 = 0;
296  G4bool bad = true;
297 
298  while (itry1 < itry_max && icase > 0 && bad) {
299  itry1++;
300  G4int itry = 0;
301 
302  while (EEXS_new < 0.0 && itry < itry_max) {
303  itry++;
304  G4double R = inuclRndm();
305  G4double X;
306 
307  if (NEX == 2) {
308  X = 1.0 - std::sqrt(R);
309 
310  } else {
311  G4double QEX2 = 1.0 / QEX;
312  G4double QEX1 = 1.0 / (QEX-1);
313  X = std::pow(0.5 * R, QEX2);
314 
315  for (G4int i = 0; i < 1000; i++) {
316  G4double DX = X * QEX1 *
317  (1.0 + QEX2 * X * (1.0 - R / std::pow(X, NEX)) / (1.0 - X));
318  X -= DX;
319 
320  if (std::fabs(DX / X) < 0.01) break;
321 
322  };
323  };
324  EPART = EB - X * E1;
325  EEXS_new = EB - EPART * A / (A-1);
326  } // while (EEXS_new < 0.0...
327 
328  if (itry == itry_max || EEXS_new < 0.0) {
329  icase = 0;
330  continue;
331  }
332 
333  if (verboseLevel > 2)
334  G4cout << " particle " << ptype << " escape " << G4endl;
335 
336  EPART /= GeV; // From MeV to GeV
337 
338  G4InuclElementaryParticle particle(ptype);
339  particle.setModel(G4InuclParticle::NonEquilib);
340 
341  // generate particle momentum
342  G4double mass = particle.getMass();
343  G4double pmod = std::sqrt(EPART * (2.0 * mass + EPART));
344  G4LorentzVector mom = generateWithRandomAngles(pmod,mass);
345 
346  // Push evaporated paricle into current rest frame
347  mom = toTheExitonSystemRestFrame.backToTheLab(mom);
348 
349  // Adjust quasiparticle and nucleon counts
350  G4int QPP_new = QPP;
351  G4int QNP_new = QNP;
352 
353  G4int A_new = A-1;
354  G4int Z_new = Z;
355 
356  if (ptype == 1) {
357  QPP_new--;
358  Z_new--;
359  };
360 
361  if (ptype == 2) QNP_new--;
362 
363  if (verboseLevel > 3) {
364  G4cout << " nucleus px " << PEX.px() << " py " << PEX.py()
365  << " pz " << PEX.pz() << " E " << PEX.e() << G4endl
366  << " evaporate px " << mom.px() << " py " << mom.py()
367  << " pz " << mom.pz() << " E " << mom.e() << G4endl;
368  }
369 
370  // New excitation energy depends on residual nuclear state
371  G4double mass_new = G4InuclNuclei::getNucleiMass(A_new, Z_new);
372 
373  EEXS_new = ((PEX-mom).m() - mass_new)*GeV;
374  if (EEXS_new < 0.) continue; // Sanity check for new nucleus
375 
376  if (verboseLevel > 3)
377  G4cout << " EEXS_new " << EEXS_new << G4endl;
378 
379  PEX -= mom;
380  EEXS = EEXS_new;
381 
382  A = A_new;
383  Z = Z_new;
384 
385  NEX--;
386  QEX--;
387  QP--;
388  QPP = QPP_new;
389  QNP = QNP_new;
390 
391  particle.setMomentum(mom);
392  output.addOutgoingParticle(particle);
393  ppout += mom;
394  if (verboseLevel > 3) {
395  G4cout << particle << G4endl
396  << " ppout px " << ppout.px() << " py " << ppout.py()
397  << " pz " << ppout.pz() << " E " << ppout.e() << G4endl;
398  }
399 
400  bad = false;
401  } // while (itry1<itry_max && icase>0
402 
403  if (itry1 == itry_max) icase = 0;
404  } // if (E < 0.) [else]
405  } // if (try_again && icase != 0)
406  } // if (try_again)
407  } // if (icase > 0)
408 
409  if (icase == 0 && try_again) { // N -> N + 2
410  if (verboseLevel > 3) G4cout << " adding excitons" << G4endl;
411 
412  G4double TNN = 1.6 * EFN + ESP;
413  G4double TNP = 1.6 * EFP + ESP;
414  G4double XNUN = 1.0 / (1.6 + ESP / EFN);
415  G4double XNUP = 1.0 / (1.6 + ESP / EFP);
416  G4double SNN1 = csNN(TNP) * XNUP;
417  G4double SNN2 = csNN(TNN) * XNUN;
418  G4double SPN1 = csPN(TNP) * XNUP;
419  G4double SPN2 = csPN(TNN) * XNUN;
420  G4double PP = (QPP * SNN1 + QNP * SPN1) * ZR;
421  G4double PN = (QPP * SPN2 + QNP * SNN2) * (AR - ZR);
422  G4double PW = PP + PN;
423  NEX += 2;
424  QEX += 2;
425  QP++;
426  QH++;
427  AR--;
428 
429  if (AR > 1) {
430  G4double SL = PW * inuclRndm();
431 
432  if (SL > PP) {
433  QNP++;
434  QNH++;
435  } else {
436  QPP++;
437  QPH++;
438  ZR--;
439  if (ZR < 2) try_again = false;
440  }
441  } else try_again = false;
442  } // if (icase==0 && try_again)
443  } // if (try_again)
444  } else try_again = false; // if (EMN > eexs_cut)
445  } else try_again = false; // if (QEX < sqrg(2*EG)
446  } else try_again = false; // if (A > a_cut ...
447  } // while (try_again)
448 
449  // everything finished, set output nuclei
450 
451  if (output.numberOfOutgoingParticles() == 0) {
452  output.addOutgoingNucleus(*nuclei_target);
453  } else {
454  G4LorentzVector pnuc = pin - ppout;
455  G4InuclNuclei nuclei(pnuc, A, Z, EEXS, G4InuclParticle::NonEquilib);
456 
457  if (verboseLevel > 3) G4cout << " remaining nucleus\n" << nuclei << G4endl;
458  output.addOutgoingNucleus(nuclei);
459  }
460 
461  validateOutput(0, target, output); // Check energy conservation, etc.
462  return;
463 }
464 
465 G4double G4NonEquilibriumEvaporator::getMatrixElement(G4int A) const {
466 
467  if (verboseLevel > 3) {
468  G4cout << " >>> G4NonEquilibriumEvaporator::getMatrixElement" << G4endl;
469  }
470 
471  G4double me;
472 
473  if (A > 150) me = 100.0;
474  else if (A > 20) me = 140.0;
475  else me = 70.0;
476 
477  return me;
478 }
479 
480 G4double G4NonEquilibriumEvaporator::getE0(G4int ) const {
481  if (verboseLevel > 3) {
482  G4cout << " >>> G4NonEquilibriumEvaporator::getEO" << G4endl;
483  }
484 
485  const G4double e0 = 200.0;
486 
487  return e0;
488 }
489 
490 G4double G4NonEquilibriumEvaporator::getParLev(G4int A,
491  G4int ) const {
492 
493  if (verboseLevel > 3) {
494  G4cout << " >>> G4NonEquilibriumEvaporator::getParLev" << G4endl;
495  }
496 
497  // const G4double par = 0.125;
498  G4double pl = 0.125 * A;
499 
500  return pl;
501 }
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