source: trunk/source/processes/hadronic/models/high_energy/src/G4HEAntiNeutronInelastic.cc@ 1350

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

geant4 tag 9.4
File size: 24.3 KB
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25//
26// $Id: G4HEAntiNeutronInelastic.cc,v 1.17 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 is 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 "G4HEAntiNeutronInelastic.hh"
43
44G4HadFinalState*
45G4HEAntiNeutronInelastic::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 << "GHEAntiNeutronInelastic: incident energy < 1 GeV" << G4endl;;
62
63 if (verboseLevel > 1) {
64 G4cout << "G4HEAntiNeutronInelastic::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 incidentKineticEnergy -= excitation;
92 incidentTotalEnergy = incidentKineticEnergy + incidentMass;
93 incidentTotalMomentum = std::sqrt( (incidentTotalEnergy-incidentMass)
94 *(incidentTotalEnergy+incidentMass));
95
96 G4HEVector targetParticle;
97 if (G4UniformRand() < atomicNumber/atomicWeight) {
98 targetParticle.setDefinition("Proton");
99 } else {
100 targetParticle.setDefinition("Neutron");
101 }
102
103 G4double targetMass = targetParticle.getMass();
104 G4double centerOfMassEnergy = std::sqrt(incidentMass*incidentMass
105 + targetMass*targetMass
106 + 2.0*targetMass*incidentTotalEnergy);
107 G4double availableEnergy = centerOfMassEnergy - targetMass - incidentMass;
108
109 G4bool inElastic = true;
110 vecLength = 0;
111
112 if (verboseLevel > 1)
113 G4cout << "ApplyYourself: CallFirstIntInCascade for particle "
114 << incidentCode << G4endl;
115
116 G4bool successful = false;
117
118 FirstIntInCasAntiNeutron(inElastic, availableEnergy, pv, vecLength,
119 incidentParticle, targetParticle, atomicWeight);
120
121 if (verboseLevel > 1)
122 G4cout << "ApplyYourself::StrangeParticlePairProduction" << G4endl;
123
124 if ((vecLength > 0) && (availableEnergy > 1.))
125 StrangeParticlePairProduction(availableEnergy, centerOfMassEnergy,
126 pv, vecLength,
127 incidentParticle, targetParticle);
128 HighEnergyCascading(successful, pv, vecLength,
129 excitationEnergyGNP, excitationEnergyDTA,
130 incidentParticle, targetParticle,
131 atomicWeight, atomicNumber);
132 if (!successful)
133 HighEnergyClusterProduction(successful, pv, vecLength,
134 excitationEnergyGNP, excitationEnergyDTA,
135 incidentParticle, targetParticle,
136 atomicWeight, atomicNumber);
137 if (!successful)
138 MediumEnergyCascading(successful, pv, vecLength,
139 excitationEnergyGNP, excitationEnergyDTA,
140 incidentParticle, targetParticle,
141 atomicWeight, atomicNumber);
142
143 if (!successful)
144 MediumEnergyClusterProduction(successful, pv, vecLength,
145 excitationEnergyGNP, excitationEnergyDTA,
146 incidentParticle, targetParticle,
147 atomicWeight, atomicNumber);
148 if (!successful)
149 QuasiElasticScattering(successful, pv, vecLength,
150 excitationEnergyGNP, excitationEnergyDTA,
151 incidentParticle, targetParticle,
152 atomicWeight, atomicNumber);
153 if (!successful)
154 ElasticScattering(successful, pv, vecLength,
155 incidentParticle,
156 atomicWeight, atomicNumber);
157
158 if (!successful)
159 G4cout << "GHEInelasticInteraction::ApplyYourself fails to produce final state particles"
160 << G4endl;
161
162 FillParticleChange(pv, vecLength);
163 delete [] pv;
164 theParticleChange.SetStatusChange(stopAndKill);
165 return &theParticleChange;
166}
167
168
169void
170G4HEAntiNeutronInelastic::FirstIntInCasAntiNeutron(G4bool& inElastic,
171 const G4double availableEnergy,
172 G4HEVector pv[],
173 G4int& vecLen,
174 const G4HEVector& incidentParticle,
175 const G4HEVector& targetParticle,
176 const G4double atomicWeight)
177
178// AntiNeutron undergoes interaction with nucleon within a nucleus. Check if
179// it is energetically possible to produce pions/kaons. If not, assume
180// nuclear excitation occurs and input particle is degraded in energy. No
181// 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=std::max(0,np-2); nm<=np; 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 for( i=0; i<numSec; i++ )neutnorm[i] = 0.0;
241 counter = -1;
242 for( np=0; np<numSec/3; np++ )
243 {
244 for( nm=std::max(0,np-1); nm<=(np+1); nm++ )
245 {
246 for( nz=0; nz<numSec/3; nz++ )
247 {
248 if( ++counter < numMul )
249 {
250 nt = np+nm+nz;
251 if( (nt>0) && (nt<=numSec) )
252 {
253 neutmul[counter] = pmltpc(np,nm,nz,nt,neutb,c);
254 neutnorm[nt-1] += neutmul[counter];
255 }
256 }
257 }
258 }
259 }
260 for( i=0; i<numSec; i++ )
261 {
262 if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i];
263 if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i];
264 }
265 // annihilation
266 for( i=0; i<numMulAn ; i++ ) protmulAn[i] = 0.0;
267 for( i=0; i<numSec ; i++ ) protnormAn[i] = 0.0;
268 counter = -1;
269 for( np=1; np<(numSec/3); np++ )
270 {
271 nm = std::max(0,np-1);
272 for( nz=0; nz<numSec/3; nz++ )
273 {
274 if( ++counter < numMulAn )
275 {
276 nt = np+nm+nz;
277 if( (nt>1) && (nt<=numSec) )
278 {
279 protmulAn[counter] = pmltpc(np,nm,nz,nt,protb,c);
280 protnormAn[nt-1] += protmulAn[counter];
281 }
282 }
283 }
284 }
285 for( i=0; i<numMulAn; i++ ) neutmulAn[i] = 0.0;
286 for( i=0; i<numSec; i++ ) neutnormAn[i] = 0.0;
287 counter = -1;
288 for( np=0; np<numSec/3; np++ )
289 {
290 nm = np;
291 for( nz=0; nz<numSec/3; nz++ )
292 {
293 if( ++counter < numMulAn )
294 {
295 nt = np+nm+nz;
296 if( (nt>1) && (nt<=numSec) )
297 {
298 neutmulAn[counter] = pmltpc(np,nm,nz,nt,neutb,c);
299 neutnormAn[nt-1] += neutmulAn[counter];
300 }
301 }
302 }
303 }
304 for( i=0; i<numSec; i++ )
305 {
306 if( protnormAn[i] > 0.0 )protnormAn[i] = 1.0/protnormAn[i];
307 if( neutnormAn[i] > 0.0 )neutnormAn[i] = 1.0/neutnormAn[i];
308 }
309 } // end of initialization
310
311
312 // initialize the first two places
313 // the same as beam and target
314 pv[0] = incidentParticle;
315 pv[1] = targetParticle;
316 vecLen = 2;
317
318 if( !inElastic )
319 { // nb n --> pb p
320 if( targetCode == neutronCode )
321 {
322 G4double cech[] = {0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.06, 0.04, 0.005, 0.};
323
324 G4int iplab = std::min(9, G4int( incidentTotalMomentum*2.5));
325 if( G4UniformRand() < cech[iplab]/std::pow(atomicWeight,0.42) )
326 {
327 pv[0] = AntiProton;
328 pv[1] = Proton;
329 }
330 }
331 return;
332 }
333 else if (availableEnergy <= PionPlus.getMass())
334 return;
335
336 // inelastic scattering
337
338 np = 0, nm = 0, nz = 0;
339 G4double anhl[] = {1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 0.97, 0.88,
340 0.85, 0.81, 0.75, 0.64, 0.64, 0.55, 0.55, 0.45, 0.47, 0.40,
341 0.39, 0.36, 0.33, 0.10, 0.01};
342 G4int iplab = G4int( incidentTotalMomentum*10.);
343 if ( iplab > 9) iplab = 10 + G4int( (incidentTotalMomentum -1.)*5. );
344 if ( iplab > 14) iplab = 15 + G4int( incidentTotalMomentum -2. );
345 if ( iplab > 22) iplab = 23 + G4int( (incidentTotalMomentum -10.)/10.);
346 iplab = std::min(24, iplab);
347
348 if ( G4UniformRand() > anhl[iplab] )
349 {
350
351 G4double eab = availableEnergy;
352 G4int ieab = G4int( eab*5.0 );
353
354 G4double supp[] = {0., 0.4, 0.55, 0.65, 0.75, 0.82, 0.86, 0.90, 0.94, 0.98};
355 if( (ieab <= 9) && (G4UniformRand() >= supp[ieab]) )
356 {
357 // suppress high multiplicity events at low momentum
358 // only one additional pion will be produced
359 G4double w0, wp, wm, wt, ran;
360 if( targetCode == protonCode ) // target is a proton
361 {
362 w0 = - sqr(1.+protb)/(2.*c*c);
363 w0 = wp = std::exp(w0);
364 if( G4UniformRand() < w0/(w0+wp) )
365 { np = 0; nm = 0; nz = 1; }
366 else
367 { np = 1; nm = 0; nz = 0; }
368 }
369 else
370 { // target is a neutron
371 w0 = -sqr(1.+neutb)/(2.*c*c);
372 w0 = wp = std::exp(w0);
373 wm = -sqr(-1.+neutb)/(2.*c*c);
374 wm = std::exp(wm);
375 wt = w0+wp+wm;
376 wp = w0+wp;
377 ran = G4UniformRand();
378 if( ran < w0/wt)
379 { np = 0; nm = 0; nz = 1; }
380 else if( ran < wp/wt)
381 { np = 1; nm = 0; nz = 0; }
382 else
383 { np = 0; nm = 1; nz = 0; }
384 }
385 }
386 else
387 {
388 // number of total particles vs. centre of mass Energy - 2*proton mass
389
390 G4double aleab = std::log(availableEnergy);
391 G4double n = 3.62567+aleab*(0.665843+aleab*(0.336514
392 + aleab*(0.117712+0.0136912*aleab))) - 2.0;
393
394 // normalization constant for kno-distribution.
395 // calculate first the sum of all constants, check for numerical problems.
396 G4double test, dum, anpn = 0.0;
397
398 for (nt=1; nt<=numSec; nt++) {
399 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
400 dum = pi*nt/(2.0*n*n);
401
402 if (std::fabs(dum) < 1.0) {
403 if( test >= 1.0e-10 )anpn += dum*test;
404 } else {
405 anpn += dum*test;
406 }
407 }
408
409 G4double ran = G4UniformRand();
410 G4double excs = 0.0;
411 if (targetCode == protonCode) {
412 counter = -1;
413 for (np=0; np<numSec/3; np++) {
414 for (nm=std::max(0,np-2); nm<=np; nm++) {
415 for (nz=0; nz<numSec/3; nz++) {
416 if (++counter < numMul) {
417 nt = np+nm+nz;
418 if ( (nt>0) && (nt<=numSec) ) {
419 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
420 dum = (pi/anpn)*nt*protmul[counter]*protnorm[nt-1]/(2.0*n*n);
421
422 if (std::fabs(dum) < 1.0) {
423 if( test >= 1.0e-10 )excs += dum*test;
424 } else {
425 excs += dum*test;
426 }
427
428 if (ran < excs) goto outOfLoop; //----------------------->
429 }
430 }
431 }
432 }
433 }
434
435 // 3 previous loops continued to the end
436 inElastic = false; // quasi-elastic scattering
437 return;
438
439 } else { // target must be a neutron
440 counter = -1;
441 for (np=0; np<numSec/3; np++) {
442 for (nm=std::max(0,np-1); nm<=(np+1); nm++) {
443 for (nz=0; nz<numSec/3; nz++) {
444 if (++counter < numMul) {
445 nt = np+nm+nz;
446 if ((nt>0) && (nt<=numSec) ) {
447 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
448 dum = (pi/anpn)*nt*neutmul[counter]*neutnorm[nt-1]/(2.0*n*n);
449 if (std::fabs(dum) < 1.0) {
450 if( test >= 1.0e-10 )excs += dum*test;
451 } else {
452 excs += dum*test;
453 }
454
455 if (ran < excs) goto outOfLoop; // -------------------------->
456 }
457 }
458 }
459 }
460 }
461 // 3 previous loops continued to the end
462 inElastic = false; // quasi-elastic scattering.
463 return;
464 }
465 }
466 outOfLoop: // <------------------------------------------------------------------------
467
468 if( targetCode == protonCode)
469 {
470 if( np == nm)
471 {
472 }
473 else if (np == (nm+1))
474 {
475 if( G4UniformRand() < 0.5)
476 {
477 pv[1] = Neutron;
478 }
479 else
480 {
481 pv[0] = AntiProton;
482 }
483 }
484 else
485 {
486 pv[0] = AntiProton;
487 pv[1] = Neutron;
488 }
489 }
490 else
491 {
492 if( np == nm)
493 {
494 if( G4UniformRand() < 0.25)
495 {
496 pv[0] = AntiProton;
497 pv[1] = Proton;
498 }
499 else
500 {
501 }
502 }
503 else if ( np == (nm-1))
504 {
505 pv[1] = Proton;
506 }
507 else
508 {
509 pv[0] = AntiProton;
510 }
511 }
512
513 }
514 else // annihilation
515 {
516 if ( availableEnergy > 2. * PionPlus.getMass() )
517 {
518
519 G4double aleab = std::log(availableEnergy);
520 G4double n = 3.62567+aleab*(0.665843+aleab*(0.336514
521 + aleab*(0.117712+0.0136912*aleab))) - 2.0;
522
523 // normalization constant for kno-distribution.
524 // calculate first the sum of all constants, check for numerical problems.
525 G4double test, dum, anpn = 0.0;
526
527 for (nt=2; nt<=numSec; nt++) {
528 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
529 dum = pi*nt/(2.0*n*n);
530 if (std::fabs(dum) < 1.0) {
531 if( test >= 1.0e-10 )anpn += dum*test;
532 } else {
533 anpn += dum*test;
534 }
535 }
536
537 G4double ran = G4UniformRand();
538 G4double excs = 0.0;
539 if (targetCode == protonCode) {
540 counter = -1;
541 for (np=1; np<numSec/3; np++) {
542 nm = np-1;
543 for (nz=0; nz<numSec/3; nz++) {
544 if (++counter < numMulAn) {
545 nt = np+nm+nz;
546 if ( (nt>1) && (nt<=numSec) ) {
547 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
548 dum = (pi/anpn)*nt*protmulAn[counter]*protnormAn[nt-1]/(2.0*n*n);
549
550 if (std::fabs(dum) < 1.0) {
551 if( test >= 1.0e-10 )excs += dum*test;
552 } else {
553 excs += dum*test;
554 }
555
556 if (ran < excs) goto outOfLoopAn; //----------------------->
557 }
558 }
559 }
560 }
561 // 3 previous loops continued to the end
562 inElastic = false; // quasi-elastic scattering
563 return;
564
565 } else { // target must be a neutron
566 counter = -1;
567 for (np=0; np<numSec/3; np++) {
568 nm = np;
569 for (nz=0; nz<numSec/3; nz++) {
570 if (++counter < numMulAn) {
571 nt = np+nm+nz;
572 if ( (nt>1) && (nt<=numSec) ) {
573 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
574 dum = (pi/anpn)*nt*neutmulAn[counter]*neutnormAn[nt-1]/(2.0*n*n);
575
576 if (std::fabs(dum) < 1.0) {
577 if( test >= 1.0e-10 )excs += dum*test;
578 } else {
579 excs += dum*test;
580 }
581
582 if (ran < excs) goto outOfLoopAn; // -------------------------->
583 }
584 }
585 }
586 }
587 inElastic = false; // quasi-elastic scattering.
588 return;
589 }
590 outOfLoopAn: // <------------------------------------------------------------------
591 vecLen = 0;
592 }
593 }
594
595 nt = np + nm + nz;
596 while ( nt > 0)
597 {
598 G4double ran = G4UniformRand();
599 if ( ran < (G4double)np/nt)
600 {
601 if( np > 0 )
602 { pv[vecLen++] = PionPlus;
603 np--;
604 }
605 }
606 else if ( ran < (G4double)(np+nm)/nt)
607 {
608 if( nm > 0 )
609 {
610 pv[vecLen++] = PionMinus;
611 nm--;
612 }
613 }
614 else
615 {
616 if( nz > 0 )
617 {
618 pv[vecLen++] = PionZero;
619 nz--;
620 }
621 }
622 nt = np + nm + nz;
623 }
624 if (verboseLevel > 1)
625 {
626 G4cout << "Particles produced: " ;
627 G4cout << pv[0].getName() << " " ;
628 G4cout << pv[1].getName() << " " ;
629 for (i=2; i < vecLen; i++)
630 {
631 G4cout << pv[i].getName() << " " ;
632 }
633 G4cout << G4endl;
634 }
635 return;
636 }
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