source: trunk/source/processes/hadronic/models/high_energy/src/G4HEAntiProtonInelastic.cc@ 1350

Last change on this file since 1350 was 1347, checked in by garnier, 15 years ago

geant4 tag 9.4
File size: 25.8 KB
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25//
26// $Id: G4HEAntiProtonInelastic.cc,v 1.16 2010/11/29 05:44:44 dennis Exp $
27// GEANT4 tag $Name: geant4-09-04-ref-00 $
28//
29
30#include "globals.hh"
31#include "G4ios.hh"
32
33// G4 Process: Gheisha High Energy Collision model.
34// This includes the high energy cascading model, the two-body-resonance model
35// and the low energy two-body model. Not included are the low energy stuff
36// like nuclear reactions, nuclear fission without any cascading and all
37// processes for particles at rest.
38// First work done by J.L.Chuma and F.W.Jones, TRIUMF, June 96.
39// H. Fesefeldt, RWTH-Aachen, 23-October-1996
40// Last modified: 29-July-1998
41
42#include "G4HEAntiProtonInelastic.hh"
43
44G4HadFinalState*
45G4HEAntiProtonInelastic::ApplyYourself(const G4HadProjectile& aTrack,
46 G4Nucleus& targetNucleus)
47{
48 G4HEVector* pv = new G4HEVector[MAXPART];
49 const G4HadProjectile* aParticle = &aTrack;
50 const G4double atomicWeight = targetNucleus.GetN();
51 const G4double atomicNumber = targetNucleus.GetZ();
52 G4HEVector incidentParticle(aParticle);
53
54 G4int incidentCode = incidentParticle.getCode();
55 G4double incidentMass = incidentParticle.getMass();
56 G4double incidentTotalEnergy = incidentParticle.getEnergy();
57 G4double incidentTotalMomentum = incidentParticle.getTotalMomentum();
58 G4double incidentKineticEnergy = incidentTotalEnergy - incidentMass;
59
60 if (incidentKineticEnergy < 1.)
61 G4cout << "GHEAntiProtonInelastic: incident energy < 1 GeV" << G4endl;
62
63 if (verboseLevel > 1) {
64 G4cout << "G4HEAntiProtonInelastic::ApplyYourself" << G4endl;
65 G4cout << "incident particle " << incidentParticle.getName()
66 << "mass " << incidentMass
67 << "kinetic energy " << incidentKineticEnergy
68 << G4endl;
69 G4cout << "target material with (A,Z) = ("
70 << atomicWeight << "," << atomicNumber << ")" << G4endl;
71 }
72
73 G4double inelasticity = NuclearInelasticity(incidentKineticEnergy,
74 atomicWeight, atomicNumber);
75 if (verboseLevel > 1)
76 G4cout << "nuclear inelasticity = " << inelasticity << G4endl;
77
78 incidentKineticEnergy -= inelasticity;
79
80 G4double excitationEnergyGNP = 0.;
81 G4double excitationEnergyDTA = 0.;
82
83 G4double excitation = NuclearExcitation(incidentKineticEnergy,
84 atomicWeight, atomicNumber,
85 excitationEnergyGNP,
86 excitationEnergyDTA);
87 if (verboseLevel > 1)
88 G4cout << "nuclear excitation = " << excitation << excitationEnergyGNP
89 << excitationEnergyDTA << G4endl;
90
91
92 incidentKineticEnergy -= excitation;
93 incidentTotalEnergy = incidentKineticEnergy + incidentMass;
94 incidentTotalMomentum = std::sqrt( (incidentTotalEnergy-incidentMass)
95 *(incidentTotalEnergy+incidentMass));
96
97 G4HEVector targetParticle;
98 if (G4UniformRand() < atomicNumber/atomicWeight) {
99 targetParticle.setDefinition("Proton");
100 } else {
101 targetParticle.setDefinition("Neutron");
102 }
103
104 G4double targetMass = targetParticle.getMass();
105 G4double centerOfMassEnergy = std::sqrt(incidentMass*incidentMass
106 + targetMass*targetMass
107 + 2.0*targetMass*incidentTotalEnergy);
108 G4double availableEnergy = centerOfMassEnergy - targetMass - incidentMass;
109
110 G4bool inElastic = true;
111 vecLength = 0;
112
113 if (verboseLevel > 1)
114 G4cout << "ApplyYourself: CallFirstIntInCascade for particle "
115 << incidentCode << G4endl;
116
117 G4bool successful = false;
118
119 FirstIntInCasAntiProton(inElastic, availableEnergy, pv, vecLength,
120 incidentParticle, targetParticle, atomicWeight);
121
122 if (verboseLevel > 1)
123 G4cout << "ApplyYourself::StrangeParticlePairProduction" << G4endl;
124
125 if ((vecLength > 0) && (availableEnergy > 1.))
126 StrangeParticlePairProduction(availableEnergy, centerOfMassEnergy,
127 pv, vecLength,
128 incidentParticle, targetParticle);
129 HighEnergyCascading(successful, pv, vecLength,
130 excitationEnergyGNP, excitationEnergyDTA,
131 incidentParticle, targetParticle,
132 atomicWeight, atomicNumber);
133 if (!successful)
134 HighEnergyClusterProduction(successful, pv, vecLength,
135 excitationEnergyGNP, excitationEnergyDTA,
136 incidentParticle, targetParticle,
137 atomicWeight, atomicNumber);
138 if (!successful)
139 MediumEnergyCascading(successful, pv, vecLength,
140 excitationEnergyGNP, excitationEnergyDTA,
141 incidentParticle, targetParticle,
142 atomicWeight, atomicNumber);
143
144 if (!successful)
145 MediumEnergyClusterProduction(successful, pv, vecLength,
146 excitationEnergyGNP, excitationEnergyDTA,
147 incidentParticle, targetParticle,
148 atomicWeight, atomicNumber);
149 if (!successful)
150 QuasiElasticScattering(successful, pv, vecLength,
151 excitationEnergyGNP, excitationEnergyDTA,
152 incidentParticle, targetParticle,
153 atomicWeight, atomicNumber);
154 if (!successful)
155 ElasticScattering(successful, pv, vecLength,
156 incidentParticle,
157 atomicWeight, atomicNumber);
158
159 if (!successful)
160 G4cout << "GHEInelasticInteraction::ApplyYourself fails to produce final state particles"
161 << G4endl;
162
163 FillParticleChange(pv, vecLength);
164 delete [] pv;
165 theParticleChange.SetStatusChange(stopAndKill);
166 return & theParticleChange;
167}
168
169
170void
171G4HEAntiProtonInelastic::FirstIntInCasAntiProton(G4bool& inElastic,
172 const G4double availableEnergy,
173 G4HEVector pv[],
174 G4int& vecLen,
175 const G4HEVector& incidentParticle,
176 const G4HEVector& targetParticle,
177 const G4double atomicWeight)
178
179// AntiProton undergoes interaction with nucleon within a nucleus. Check if it is
180// energetically possible to produce pions/kaons. In not, assume nuclear excitation
181// occurs and input particle is degraded in energy. No other particles are produced.
182// If reaction is possible, find the correct number of pions/protons/neutrons
183// produced using an interpolation to multiplicity data. Replace some pions or
184// protons/neutrons by kaons or strange baryons according to the average
185// multiplicity per inelastic reaction.
186{
187 static const G4double expxu = std::log(MAXFLOAT); // upper bound for arg. of exp
188 static const G4double expxl = -expxu; // lower bound for arg. of exp
189
190 static const G4double protb = 0.7;
191 static const G4double neutb = 0.7;
192 static const G4double c = 1.25;
193
194 static const G4int numMul = 1200;
195 static const G4int numMulAn = 400;
196 static const G4int numSec = 60;
197
198 G4int neutronCode = Neutron.getCode();
199 G4int protonCode = Proton.getCode();
200
201 G4int targetCode = targetParticle.getCode();
202 G4double incidentTotalMomentum = incidentParticle.getTotalMomentum();
203
204 static G4bool first = true;
205 static G4double protmul[numMul], protnorm[numSec]; // proton constants
206 static G4double protmulAn[numMulAn],protnormAn[numSec];
207 static G4double neutmul[numMul], neutnorm[numSec]; // neutron constants
208 static G4double neutmulAn[numMulAn],neutnormAn[numSec];
209
210 // misc. local variables
211 // np = number of pi+, nm = number of pi-, nz = number of pi0
212
213 G4int i, counter, nt, np, nm, nz;
214
215 if( first )
216 { // compute normalization constants, this will only be done once
217 first = false;
218 for( i=0; i<numMul ; i++ ) protmul[i] = 0.0;
219 for( i=0; i<numSec ; i++ ) protnorm[i] = 0.0;
220 counter = -1;
221 for( np=0; np<(numSec/3); np++ )
222 {
223 for( nm=Imax(0,np-1); nm<=(np+1); nm++ )
224 {
225 for( nz=0; nz<numSec/3; nz++ )
226 {
227 if( ++counter < numMul )
228 {
229 nt = np+nm+nz;
230 if( (nt>0) && (nt<=numSec) )
231 {
232 protmul[counter] = pmltpc(np,nm,nz,nt,protb,c);
233 protnorm[nt-1] += protmul[counter];
234 }
235 }
236 }
237 }
238 }
239 for( i=0; i<numMul; i++ )neutmul[i] = 0.0;
240
241 for( i=0; i<numSec; i++ )neutnorm[i] = 0.0;
242 counter = -1;
243 for( np=0; np<numSec/3; np++ )
244 {
245 for( nm=np; nm<=(np+2); nm++ )
246 {
247 for( nz=0; nz<numSec/3; nz++ )
248 {
249 if( ++counter < numMul )
250 {
251 nt = np+nm+nz;
252 if( (nt>0) && (nt<=numSec) )
253 {
254 neutmul[counter] = pmltpc(np,nm,nz,nt,neutb,c);
255 neutnorm[nt-1] += neutmul[counter];
256 }
257 }
258 }
259 }
260 }
261 for( i=0; i<numSec; i++ )
262 {
263 if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i];
264 if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i];
265 }
266 // annihilation
267 for( i=0; i<numMulAn ; i++ ) protmulAn[i] = 0.0;
268 for( i=0; i<numSec ; i++ ) protnormAn[i] = 0.0;
269 counter = -1;
270 for( np=1; np<(numSec/3); np++ )
271 {
272 nm = np;
273 for( nz=0; nz<numSec/3; nz++ )
274 {
275 if( ++counter < numMulAn )
276 {
277 nt = np+nm+nz;
278 if( (nt>0) && (nt<=numSec) )
279 {
280 protmulAn[counter] = pmltpc(np,nm,nz,nt,protb,c);
281 protnormAn[nt-1] += protmulAn[counter];
282 }
283 }
284 }
285 }
286 for( i=0; i<numMulAn; i++ ) neutmulAn[i] = 0.0;
287 for( i=0; i<numSec; i++ ) neutnormAn[i] = 0.0;
288 counter = -1;
289 for( np=1; np<numSec/3; np++ )
290 {
291 nm = np+1;
292 for( nz=0; nz<numSec/3; nz++ )
293 {
294 if( ++counter < numMulAn )
295 {
296 nt = np+nm+nz;
297 if( (nt>0) && (nt<=numSec) )
298 {
299 neutmulAn[counter] = pmltpc(np,nm,nz,nt,neutb,c);
300 neutnormAn[nt-1] += neutmulAn[counter];
301 }
302 }
303 }
304 }
305 for( i=0; i<numSec; i++ )
306 {
307 if( protnormAn[i] > 0.0 )protnormAn[i] = 1.0/protnormAn[i];
308 if( neutnormAn[i] > 0.0 )neutnormAn[i] = 1.0/neutnormAn[i];
309 }
310 } // end of initialization
311
312
313 // initialize the first two places
314 // the same as beam and target
315 pv[0] = incidentParticle;
316 pv[1] = targetParticle;
317 vecLen = 2;
318
319 if( !inElastic )
320 { // pb p --> nb n
321 if( targetCode == protonCode )
322 {
323 G4double cech[] = {0.14, 0.170, 0.180, 0.180, 0.180, 0.170, 0.170, 0.160, 0.155, 0.145,
324 0.11, 0.082, 0.065, 0.050, 0.041, 0.035, 0.028, 0.024, 0.010, 0.000};
325
326 G4int iplab = G4int( incidentTotalMomentum*10.);
327 if (iplab > 9) iplab = Imin(19, G4int( incidentTotalMomentum) + 9);
328 if( G4UniformRand() < cech[iplab]/std::pow(atomicWeight,0.42) )
329 { // charge exchange pi+ n -> pi0 p
330 pv[0] = AntiNeutron;
331 pv[1] = Neutron;
332 }
333 }
334 return;
335 }
336 else if (availableEnergy <= PionPlus.getMass())
337 return;
338
339 // inelastic scattering
340
341 np = 0; nm = 0; nz = 0;
342 G4double anhl[] = {1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 0.90,
343 0.60, 0.52, 0.47, 0.44, 0.41, 0.39, 0.37, 0.35, 0.34, 0.24,
344 0.19, 0.15, 0.12, 0.10, 0.09, 0.07, 0.06, 0.05, 0.00};
345 G4int iplab = G4int( incidentTotalMomentum*10.);
346 if ( iplab > 9) iplab = 9 + G4int( incidentTotalMomentum);
347 if ( iplab > 18) iplab = 18 + G4int( incidentTotalMomentum*10.);
348 iplab = Imin(28, iplab);
349
350 if ( G4UniformRand() > anhl[iplab] )
351 {
352
353 G4double eab = availableEnergy;
354 G4int ieab = G4int( eab*5.0 );
355
356 G4double supp[] = {0., 0.4, 0.55, 0.65, 0.75, 0.82, 0.86, 0.90, 0.94, 0.98};
357 if( (ieab <= 9) && (G4UniformRand() >= supp[ieab]) )
358 {
359 // suppress high multiplicity events at low momentum
360 // only one additional pion will be produced
361 G4double w0, wp, wm, wt, ran;
362 if( targetCode == neutronCode ) // target is a neutron
363 {
364 w0 = - sqr(1.+neutb)/(2.*c*c);
365 w0 = std::exp(w0);
366 wm = - sqr(-1.+neutb)/(2.*c*c);
367 wm = std::exp(wm);
368 if( G4UniformRand() < w0/(w0+wm) )
369 { np = 0; nm = 0; nz = 1; }
370 else
371 { np = 0; nm = 1; nz = 0; }
372 }
373 else
374 { // target is a proton
375 w0 = -sqr(1.+protb)/(2.*c*c);
376 w0 = std::exp(w0);
377 wp = w0;
378 wm = -sqr(-1.+protb)/(2.*c*c);
379 wm = std::exp(wm);
380 wt = w0+wp+wm;
381 wp = w0+wp;
382 ran = G4UniformRand();
383 if( ran < w0/wt)
384 { np = 0; nm = 0; nz = 1; }
385 else if( ran < wp/wt)
386 { np = 1; nm = 0; nz = 0; }
387 else
388 { np = 0; nm = 1; nz = 0; }
389 }
390 }
391 else
392 {
393 // number of total particles vs. centre of mass Energy - 2*proton mass
394
395 G4double aleab = std::log(availableEnergy);
396 G4double n = 3.62567+aleab*(0.665843+aleab*(0.336514
397 + aleab*(0.117712+0.0136912*aleab))) - 2.0;
398
399 // normalization constant for kno-distribution.
400 // calculate first the sum of all constants, check for numerical problems.
401 G4double test, dum, anpn = 0.0;
402
403 for (nt=1; nt<=numSec; nt++) {
404 test = std::exp( Amin( expxu, Amax( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
405 dum = pi*nt/(2.0*n*n);
406 if (std::fabs(dum) < 1.0) {
407 if( test >= 1.0e-10 )anpn += dum*test;
408 } else {
409 anpn += dum*test;
410 }
411 }
412
413 G4double ran = G4UniformRand();
414 G4double excs = 0.0;
415 if( targetCode == protonCode )
416 {
417 counter = -1;
418 for( np=0; np<numSec/3; np++ )
419 {
420 for( nm=Imax(0,np-1); nm<=(np+1); nm++ )
421 {
422 for( nz=0; nz<numSec/3; nz++ )
423 {
424 if( ++counter < numMul )
425 {
426 nt = np+nm+nz;
427 if ( (nt>0) && (nt<=numSec) ) {
428 test = std::exp( Amin( expxu, Amax( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
429 dum = (pi/anpn)*nt*protmul[counter]*protnorm[nt-1]/(2.0*n*n);
430 if (std::fabs(dum) < 1.0) {
431 if( test >= 1.0e-10 )excs += dum*test;
432 } else {
433 excs += dum*test;
434 }
435
436 if (ran < excs) goto outOfLoop; //----------------------->
437 }
438 }
439 }
440 }
441 }
442
443 // 3 previous loops continued to the end
444 inElastic = false; // quasi-elastic scattering
445 return;
446 }
447 else
448 { // target must be a neutron
449 counter = -1;
450 for( np=0; np<numSec/3; np++ )
451 {
452 for( nm=np; nm<=(np+2); nm++ )
453 {
454 for( nz=0; nz<numSec/3; nz++ )
455 {
456 if( ++counter < numMul )
457 {
458 nt = np+nm+nz;
459 if ( (nt>=1) && (nt<=numSec) ) {
460 test = std::exp( Amin( expxu, Amax( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
461 dum = (pi/anpn)*nt*neutmul[counter]*neutnorm[nt-1]/(2.0*n*n);
462 if (std::fabs(dum) < 1.0) {
463 if( test >= 1.0e-10 )excs += dum*test;
464 } else {
465 excs += dum*test;
466 }
467
468 if (ran < excs) goto outOfLoop; // -------------------------->
469 }
470 }
471 }
472 }
473 }
474 // 3 previous loops continued to the end
475 inElastic = false; // quasi-elastic scattering.
476 return;
477 }
478 }
479 outOfLoop: // <------------------------------------------------------------------------
480
481 if( targetCode == neutronCode)
482 {
483 if( np == nm)
484 {
485 }
486 else if (np == (nm-1))
487 {
488 if( G4UniformRand() < 0.5)
489 {
490 pv[1] = Proton;
491 }
492 else
493 {
494 pv[0] = AntiNeutron;
495 }
496 }
497 else
498 {
499 pv[0] = AntiNeutron;
500 pv[1] = Proton;
501 }
502 }
503 else
504 {
505 if( np == nm)
506 {
507 if( G4UniformRand() < 0.25)
508 {
509 pv[0] = AntiNeutron;
510 pv[1] = Neutron;
511 }
512 else
513 {
514 }
515 }
516 else if ( np == (1+nm))
517 {
518 pv[1] = Neutron;
519 }
520 else
521 {
522 pv[0] = AntiNeutron;
523 }
524 }
525
526 }
527 else // annihilation
528 {
529 if ( availableEnergy > 2. * PionPlus.getMass() )
530 {
531
532 G4double aleab = std::log(availableEnergy);
533 G4double n = 3.62567+aleab*(0.665843+aleab*(0.336514
534 + aleab*(0.117712+0.0136912*aleab))) - 2.0;
535
536 // normalization constant for kno-distribution.
537 // calculate first the sum of all constants, check for numerical problems.
538 G4double test, dum, anpn = 0.0;
539
540 for (nt=2; nt<=numSec; nt++) {
541 test = std::exp( Amin( expxu, Amax( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
542 dum = pi*nt/(2.0*n*n);
543 if (std::fabs(dum) < 1.0) {
544 if( test >= 1.0e-10 )anpn += dum*test;
545 } else {
546 anpn += dum*test;
547 }
548 }
549
550 G4double ran = G4UniformRand();
551 G4double excs = 0.0;
552 if( targetCode == protonCode )
553 {
554 counter = -1;
555 for( np=1; np<numSec/3; np++ )
556 {
557 nm = np;
558 for( nz=0; nz<numSec/3; nz++ )
559 {
560 if( ++counter < numMulAn )
561 {
562 nt = np+nm+nz;
563 if ( (nt>0) && (nt<=numSec) ) {
564 test = std::exp( Amin( expxu, Amax( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
565 dum = (pi/anpn)*nt*protmulAn[counter]*protnormAn[nt-1]/(2.0*n*n);
566 if (std::fabs(dum) < 1.0) {
567 if( test >= 1.0e-10 )excs += dum*test;
568 } else {
569 excs += dum*test;
570 }
571
572 if (ran < excs) goto outOfLoopAn; //----------------------->
573 }
574 }
575 }
576 }
577 // 3 previous loops continued to the end
578 inElastic = false; // quasi-elastic scattering
579 return;
580 }
581 else
582 { // target must be a neutron
583 counter = -1;
584 for( np=1; np<numSec/3; np++ )
585 {
586 nm = np+1;
587 for( nz=0; nz<numSec/3; nz++ )
588 {
589 if( ++counter < numMulAn )
590 {
591 nt = np+nm+nz;
592 if ( (nt>=1) && (nt<=numSec) ) {
593 test = std::exp( Amin( expxu, Amax( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
594 dum = (pi/anpn)*nt*neutmulAn[counter]*neutnormAn[nt-1]/(2.0*n*n);
595 if (std::fabs(dum) < 1.0) {
596 if( test >= 1.0e-10 )excs += dum*test;
597 } else {
598 excs += dum*test;
599 }
600
601 if (ran < excs) goto outOfLoopAn; // -------------------------->
602 }
603 }
604 }
605 }
606 inElastic = false; // quasi-elastic scattering.
607 return;
608 }
609 outOfLoopAn: // <------------------------------------------------------------------
610 vecLen = 0;
611 }
612 }
613
614 nt = np + nm + nz;
615 while ( nt > 0)
616 {
617 G4double ran = G4UniformRand();
618 if ( ran < (G4double)np/nt)
619 {
620 if( np > 0 )
621 { pv[vecLen++] = PionPlus;
622 np--;
623 }
624 }
625 else if ( ran < (G4double)(np+nm)/nt)
626 {
627 if( nm > 0 )
628 {
629 pv[vecLen++] = PionMinus;
630 nm--;
631 }
632 }
633 else
634 {
635 if( nz > 0 )
636 {
637 pv[vecLen++] = PionZero;
638 nz--;
639 }
640 }
641 nt = np + nm + nz;
642 }
643 if (verboseLevel > 1)
644 {
645 G4cout << "Particles produced: " ;
646 G4cout << pv[0].getName() << " " ;
647 G4cout << pv[1].getName() << " " ;
648 for (i=2; i < vecLen; i++)
649 {
650 G4cout << pv[i].getName() << " " ;
651 }
652 G4cout << G4endl;
653 }
654 return;
655 }
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