source: trunk/source/processes/hadronic/models/high_energy/src/G4HEAntiNeutronInelastic.cc@ 1201

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update CVS release candidate geant4.9.3.01
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20// * By using, copying, modifying or distributing the software (or *
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25//
26//
27// $Id: G4HEAntiNeutronInelastic.cc,v 1.15 2008/03/17 20:49:17 dennis Exp $
28// GEANT4 tag $Name: geant4-09-03-cand-01 $
29//
30//
31
32#include "globals.hh"
33#include "G4ios.hh"
34
35//
36// G4 Process: Gheisha High Energy Collision model.
37// This includes the high energy cascading model, the two-body-resonance model
38// and the low energy two-body model. Not included are the low energy stuff like
39// nuclear reactions, nuclear fission without any cascading and all processes for
40// particles at rest.
41// First work done by J.L.Chuma and F.W.Jones, TRIUMF, June 96.
42// H. Fesefeldt, RWTH-Aachen, 23-October-1996
43// Last modified: 29-July-1998
44
45#include "G4HEAntiNeutronInelastic.hh"
46
47G4HadFinalState * G4HEAntiNeutronInelastic::
48ApplyYourself( const G4HadProjectile &aTrack, G4Nucleus &targetNucleus )
49 {
50 G4HEVector * pv = new G4HEVector[MAXPART];
51 const G4HadProjectile *aParticle = &aTrack;
52// G4DynamicParticle *originalTarget = targetNucleus.ReturnTargetParticle();
53 const G4double atomicWeight = targetNucleus.GetN();
54 const G4double atomicNumber = targetNucleus.GetZ();
55 G4HEVector incidentParticle(aParticle);
56
57 G4int incidentCode = incidentParticle.getCode();
58 G4double incidentMass = incidentParticle.getMass();
59 G4double incidentTotalEnergy = incidentParticle.getEnergy();
60 G4double incidentTotalMomentum = incidentParticle.getTotalMomentum();
61 G4double incidentKineticEnergy = incidentTotalEnergy - incidentMass;
62
63 if(incidentKineticEnergy < 1.)
64 {
65 G4cout << "GHEAntiNeutronInelastic: incident energy < 1 GeV" << G4endl;;
66 }
67 if(verboseLevel > 1)
68 {
69 G4cout << "G4HEAntiNeutronInelastic::ApplyYourself" << G4endl;
70 G4cout << "incident particle " << incidentParticle.getName()
71 << "mass " << incidentMass
72 << "kinetic energy " << incidentKineticEnergy
73 << G4endl;
74 G4cout << "target material with (A,Z) = ("
75 << atomicWeight << "," << atomicNumber << ")" << G4endl;
76 }
77
78 G4double inelasticity = NuclearInelasticity(incidentKineticEnergy,
79 atomicWeight, atomicNumber);
80 if(verboseLevel > 1)
81 G4cout << "nuclear inelasticity = " << inelasticity << G4endl;
82
83 incidentKineticEnergy -= inelasticity;
84
85 G4double excitationEnergyGNP = 0.;
86 G4double excitationEnergyDTA = 0.;
87
88 G4double excitation = NuclearExcitation(incidentKineticEnergy,
89 atomicWeight, atomicNumber,
90 excitationEnergyGNP,
91 excitationEnergyDTA);
92 if(verboseLevel > 1)
93 G4cout << "nuclear excitation = " << excitation << excitationEnergyGNP
94 << excitationEnergyDTA << G4endl;
95
96
97 incidentKineticEnergy -= excitation;
98 incidentTotalEnergy = incidentKineticEnergy + incidentMass;
99 incidentTotalMomentum = std::sqrt( (incidentTotalEnergy-incidentMass)
100 *(incidentTotalEnergy+incidentMass));
101
102
103 G4HEVector targetParticle;
104 if(G4UniformRand() < atomicNumber/atomicWeight)
105 {
106 targetParticle.setDefinition("Proton");
107 }
108 else
109 {
110 targetParticle.setDefinition("Neutron");
111 }
112
113 G4double targetMass = targetParticle.getMass();
114 G4double centerOfMassEnergy = std::sqrt( incidentMass*incidentMass + targetMass*targetMass
115 + 2.0*targetMass*incidentTotalEnergy);
116 G4double availableEnergy = centerOfMassEnergy - targetMass - incidentMass;
117
118 // this was the meaning of inElastic in the
119 // original Gheisha stand-alone version.
120// G4bool inElastic = InElasticCrossSectionInFirstInt
121// (availableEnergy, incidentCode, incidentTotalMomentum);
122 // by unknown reasons, it has been replaced
123 // to the following code in Geant???
124 G4bool inElastic = true;
125// if (G4UniformRand() < elasticCrossSection/totalCrossSection) inElastic = false;
126
127 vecLength = 0;
128
129 if(verboseLevel > 1)
130 G4cout << "ApplyYourself: CallFirstIntInCascade for particle "
131 << incidentCode << G4endl;
132
133 G4bool successful = false;
134
135 if(inElastic || (!inElastic && atomicWeight < 1.5))
136 {
137 FirstIntInCasAntiNeutron(inElastic, availableEnergy, pv, vecLength,
138 incidentParticle, targetParticle, atomicWeight);
139
140 if(verboseLevel > 1)
141 G4cout << "ApplyYourself::StrangeParticlePairProduction" << G4endl;
142
143
144 if ((vecLength > 0) && (availableEnergy > 1.))
145 StrangeParticlePairProduction( availableEnergy, centerOfMassEnergy,
146 pv, vecLength,
147 incidentParticle, targetParticle);
148 HighEnergyCascading( successful, pv, vecLength,
149 excitationEnergyGNP, excitationEnergyDTA,
150 incidentParticle, targetParticle,
151 atomicWeight, atomicNumber);
152 if (!successful)
153 HighEnergyClusterProduction( successful, pv, vecLength,
154 excitationEnergyGNP, excitationEnergyDTA,
155 incidentParticle, targetParticle,
156 atomicWeight, atomicNumber);
157 if (!successful)
158 MediumEnergyCascading( successful, pv, vecLength,
159 excitationEnergyGNP, excitationEnergyDTA,
160 incidentParticle, targetParticle,
161 atomicWeight, atomicNumber);
162
163 if (!successful)
164 MediumEnergyClusterProduction( successful, pv, vecLength,
165 excitationEnergyGNP, excitationEnergyDTA,
166 incidentParticle, targetParticle,
167 atomicWeight, atomicNumber);
168 if (!successful)
169 QuasiElasticScattering( successful, pv, vecLength,
170 excitationEnergyGNP, excitationEnergyDTA,
171 incidentParticle, targetParticle,
172 atomicWeight, atomicNumber);
173 }
174 if (!successful)
175 {
176 ElasticScattering( successful, pv, vecLength,
177 incidentParticle,
178 atomicWeight, atomicNumber);
179 }
180
181 if (!successful)
182 {
183 G4cout << "GHEInelasticInteraction::ApplyYourself fails to produce final state particles" << G4endl;
184 }
185 FillParticleChange(pv, vecLength);
186 delete [] pv;
187 theParticleChange.SetStatusChange(stopAndKill);
188 return & theParticleChange;
189 }
190
191void
192 G4HEAntiNeutronInelastic::FirstIntInCasAntiNeutron( G4bool &inElastic,
193 const G4double availableEnergy,
194 G4HEVector pv[],
195 G4int &vecLen,
196 G4HEVector incidentParticle,
197 G4HEVector targetParticle,
198 const G4double atomicWeight)
199
200// AntiNeutron undergoes interaction with nucleon within a nucleus. Check if it is
201// energetically possible to produce pions/kaons. In not, assume nuclear excitation
202// occurs and input particle is degraded in energy. No other particles are produced.
203// If reaction is possible, find the correct number of pions/protons/neutrons
204// produced using an interpolation to multiplicity data. Replace some pions or
205// protons/neutrons by kaons or strange baryons according to the average
206// multiplicity per inelastic reaction.
207
208 {
209 static const G4double expxu = std::log(MAXFLOAT); // upper bound for arg. of exp
210 static const G4double expxl = -expxu; // lower bound for arg. of exp
211
212 static const G4double protb = 0.7;
213 static const G4double neutb = 0.7;
214 static const G4double c = 1.25;
215
216 static const G4int numMul = 1200;
217 static const G4int numMulAn = 400;
218 static const G4int numSec = 60;
219
220 G4int neutronCode = Neutron.getCode();
221 G4int protonCode = Proton.getCode();
222
223 G4int targetCode = targetParticle.getCode();
224// G4double incidentMass = incidentParticle.getMass();
225// G4double incidentEnergy = incidentParticle.getEnergy();
226 G4double incidentTotalMomentum = incidentParticle.getTotalMomentum();
227
228 static G4bool first = true;
229 static G4double protmul[numMul], protnorm[numSec]; // proton constants
230 static G4double protmulAn[numMulAn],protnormAn[numSec];
231 static G4double neutmul[numMul], neutnorm[numSec]; // neutron constants
232 static G4double neutmulAn[numMulAn],neutnormAn[numSec];
233
234 // misc. local variables
235 // np = number of pi+, nm = number of pi-, nz = number of pi0
236
237 G4int i, counter, nt, np, nm, nz;
238
239 if( first )
240 { // compute normalization constants, this will only be done once
241 first = false;
242 for( i=0; i<numMul ; i++ ) protmul[i] = 0.0;
243 for( i=0; i<numSec ; i++ ) protnorm[i] = 0.0;
244 counter = -1;
245 for( np=0; np<(numSec/3); np++ )
246 {
247 for( nm=std::max(0,np-2); nm<=np; nm++ )
248 {
249 for( nz=0; nz<numSec/3; nz++ )
250 {
251 if( ++counter < numMul )
252 {
253 nt = np+nm+nz;
254 if( (nt>0) && (nt<=numSec) )
255 {
256 protmul[counter] = pmltpc(np,nm,nz,nt,protb,c);
257 protnorm[nt-1] += protmul[counter];
258 }
259 }
260 }
261 }
262 }
263 for( i=0; i<numMul; i++ )neutmul[i] = 0.0;
264 for( i=0; i<numSec; i++ )neutnorm[i] = 0.0;
265 counter = -1;
266 for( np=0; np<numSec/3; np++ )
267 {
268 for( nm=std::max(0,np-1); nm<=(np+1); nm++ )
269 {
270 for( nz=0; nz<numSec/3; nz++ )
271 {
272 if( ++counter < numMul )
273 {
274 nt = np+nm+nz;
275 if( (nt>0) && (nt<=numSec) )
276 {
277 neutmul[counter] = pmltpc(np,nm,nz,nt,neutb,c);
278 neutnorm[nt-1] += neutmul[counter];
279 }
280 }
281 }
282 }
283 }
284 for( i=0; i<numSec; i++ )
285 {
286 if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i];
287 if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i];
288 }
289 // annihilation
290 for( i=0; i<numMulAn ; i++ ) protmulAn[i] = 0.0;
291 for( i=0; i<numSec ; i++ ) protnormAn[i] = 0.0;
292 counter = -1;
293 for( np=1; np<(numSec/3); np++ )
294 {
295 nm = std::max(0,np-1);
296 for( nz=0; nz<numSec/3; nz++ )
297 {
298 if( ++counter < numMulAn )
299 {
300 nt = np+nm+nz;
301 if( (nt>1) && (nt<=numSec) )
302 {
303 protmulAn[counter] = pmltpc(np,nm,nz,nt,protb,c);
304 protnormAn[nt-1] += protmulAn[counter];
305 }
306 }
307 }
308 }
309 for( i=0; i<numMulAn; i++ ) neutmulAn[i] = 0.0;
310 for( i=0; i<numSec; i++ ) neutnormAn[i] = 0.0;
311 counter = -1;
312 for( np=0; np<numSec/3; np++ )
313 {
314 nm = np;
315 for( nz=0; nz<numSec/3; nz++ )
316 {
317 if( ++counter < numMulAn )
318 {
319 nt = np+nm+nz;
320 if( (nt>1) && (nt<=numSec) )
321 {
322 neutmulAn[counter] = pmltpc(np,nm,nz,nt,neutb,c);
323 neutnormAn[nt-1] += neutmulAn[counter];
324 }
325 }
326 }
327 }
328 for( i=0; i<numSec; i++ )
329 {
330 if( protnormAn[i] > 0.0 )protnormAn[i] = 1.0/protnormAn[i];
331 if( neutnormAn[i] > 0.0 )neutnormAn[i] = 1.0/neutnormAn[i];
332 }
333 } // end of initialization
334
335
336 // initialize the first two places
337 // the same as beam and target
338 pv[0] = incidentParticle;
339 pv[1] = targetParticle;
340 vecLen = 2;
341
342 if( !inElastic )
343 { // nb n --> pb p
344 if( targetCode == neutronCode )
345 {
346 G4double cech[] = {0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.06, 0.04, 0.005, 0.};
347
348 G4int iplab = std::min(9, G4int( incidentTotalMomentum*2.5));
349 if( G4UniformRand() < cech[iplab]/std::pow(atomicWeight,0.42) )
350 {
351 pv[0] = AntiProton;
352 pv[1] = Proton;
353 }
354 }
355 return;
356 }
357 else if (availableEnergy <= PionPlus.getMass())
358 return;
359
360 // inelastic scattering
361
362 np = 0, nm = 0, nz = 0;
363 G4double anhl[] = {1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 0.97, 0.88,
364 0.85, 0.81, 0.75, 0.64, 0.64, 0.55, 0.55, 0.45, 0.47, 0.40,
365 0.39, 0.36, 0.33, 0.10, 0.01};
366 G4int iplab = G4int( incidentTotalMomentum*10.);
367 if ( iplab > 9) iplab = 10 + G4int( (incidentTotalMomentum -1.)*5. );
368 if ( iplab > 14) iplab = 15 + G4int( incidentTotalMomentum -2. );
369 if ( iplab > 22) iplab = 23 + G4int( (incidentTotalMomentum -10.)/10.);
370 iplab = std::min(24, iplab);
371
372 if ( G4UniformRand() > anhl[iplab] )
373 {
374
375 G4double eab = availableEnergy;
376 G4int ieab = G4int( eab*5.0 );
377
378 G4double supp[] = {0., 0.4, 0.55, 0.65, 0.75, 0.82, 0.86, 0.90, 0.94, 0.98};
379 if( (ieab <= 9) && (G4UniformRand() >= supp[ieab]) )
380 {
381 // suppress high multiplicity events at low momentum
382 // only one additional pion will be produced
383 G4double w0, wp, wm, wt, ran;
384 if( targetCode == protonCode ) // target is a proton
385 {
386 w0 = - sqr(1.+protb)/(2.*c*c);
387 w0 = wp = std::exp(w0);
388 if( G4UniformRand() < w0/(w0+wp) )
389 { np = 0; nm = 0; nz = 1; }
390 else
391 { np = 1; nm = 0; nz = 0; }
392 }
393 else
394 { // target is a neutron
395 w0 = -sqr(1.+neutb)/(2.*c*c);
396 w0 = wp = std::exp(w0);
397 wm = -sqr(-1.+neutb)/(2.*c*c);
398 wm = std::exp(wm);
399 wt = w0+wp+wm;
400 wp = w0+wp;
401 ran = G4UniformRand();
402 if( ran < w0/wt)
403 { np = 0; nm = 0; nz = 1; }
404 else if( ran < wp/wt)
405 { np = 1; nm = 0; nz = 0; }
406 else
407 { np = 0; nm = 1; nz = 0; }
408 }
409 }
410 else
411 {
412 // number of total particles vs. centre of mass Energy - 2*proton mass
413
414 G4double aleab = std::log(availableEnergy);
415 G4double n = 3.62567+aleab*(0.665843+aleab*(0.336514
416 + aleab*(0.117712+0.0136912*aleab))) - 2.0;
417
418 // normalization constant for kno-distribution.
419 // calculate first the sum of all constants, check for numerical problems.
420 G4double test, dum, anpn = 0.0;
421
422 for (nt=1; nt<=numSec; nt++) {
423 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
424 dum = pi*nt/(2.0*n*n);
425
426 if (std::fabs(dum) < 1.0) {
427 if( test >= 1.0e-10 )anpn += dum*test;
428 } else {
429 anpn += dum*test;
430 }
431 }
432
433 G4double ran = G4UniformRand();
434 G4double excs = 0.0;
435 if (targetCode == protonCode) {
436 counter = -1;
437 for (np=0; np<numSec/3; np++) {
438 for (nm=std::max(0,np-2); nm<=np; nm++) {
439 for (nz=0; nz<numSec/3; nz++) {
440 if (++counter < numMul) {
441 nt = np+nm+nz;
442 if ( (nt>0) && (nt<=numSec) ) {
443 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
444 dum = (pi/anpn)*nt*protmul[counter]*protnorm[nt-1]/(2.0*n*n);
445
446 if (std::fabs(dum) < 1.0) {
447 if( test >= 1.0e-10 )excs += dum*test;
448 } else {
449 excs += dum*test;
450 }
451
452 if (ran < excs) goto outOfLoop; //----------------------->
453 }
454 }
455 }
456 }
457 }
458
459 // 3 previous loops continued to the end
460 inElastic = false; // quasi-elastic scattering
461 return;
462
463 } else { // target must be a neutron
464 counter = -1;
465 for (np=0; np<numSec/3; np++) {
466 for (nm=std::max(0,np-1); nm<=(np+1); nm++) {
467 for (nz=0; nz<numSec/3; nz++) {
468 if (++counter < numMul) {
469 nt = np+nm+nz;
470 if ((nt>0) && (nt<=numSec) ) {
471 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
472 dum = (pi/anpn)*nt*neutmul[counter]*neutnorm[nt-1]/(2.0*n*n);
473 if (std::fabs(dum) < 1.0) {
474 if( test >= 1.0e-10 )excs += dum*test;
475 } else {
476 excs += dum*test;
477 }
478
479 if (ran < excs) goto outOfLoop; // -------------------------->
480 }
481 }
482 }
483 }
484 }
485 // 3 previous loops continued to the end
486 inElastic = false; // quasi-elastic scattering.
487 return;
488 }
489 }
490 outOfLoop: // <------------------------------------------------------------------------
491
492 if( targetCode == protonCode)
493 {
494 if( np == nm)
495 {
496 }
497 else if (np == (nm+1))
498 {
499 if( G4UniformRand() < 0.5)
500 {
501 pv[1] = Neutron;
502 }
503 else
504 {
505 pv[0] = AntiProton;
506 }
507 }
508 else
509 {
510 pv[0] = AntiProton;
511 pv[1] = Neutron;
512 }
513 }
514 else
515 {
516 if( np == nm)
517 {
518 if( G4UniformRand() < 0.25)
519 {
520 pv[0] = AntiProton;
521 pv[1] = Proton;
522 }
523 else
524 {
525 }
526 }
527 else if ( np == (nm-1))
528 {
529 pv[1] = Proton;
530 }
531 else
532 {
533 pv[0] = AntiProton;
534 }
535 }
536
537 }
538 else // annihilation
539 {
540 if ( availableEnergy > 2. * PionPlus.getMass() )
541 {
542
543 G4double aleab = std::log(availableEnergy);
544 G4double n = 3.62567+aleab*(0.665843+aleab*(0.336514
545 + aleab*(0.117712+0.0136912*aleab))) - 2.0;
546
547 // normalization constant for kno-distribution.
548 // calculate first the sum of all constants, check for numerical problems.
549 G4double test, dum, anpn = 0.0;
550
551 for (nt=2; nt<=numSec; nt++) {
552 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
553 dum = pi*nt/(2.0*n*n);
554 if (std::fabs(dum) < 1.0) {
555 if( test >= 1.0e-10 )anpn += dum*test;
556 } else {
557 anpn += dum*test;
558 }
559 }
560
561 G4double ran = G4UniformRand();
562 G4double excs = 0.0;
563 if (targetCode == protonCode) {
564 counter = -1;
565 for (np=1; np<numSec/3; np++) {
566 nm = np-1;
567 for (nz=0; nz<numSec/3; nz++) {
568 if (++counter < numMulAn) {
569 nt = np+nm+nz;
570 if ( (nt>1) && (nt<=numSec) ) {
571 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
572 dum = (pi/anpn)*nt*protmulAn[counter]*protnormAn[nt-1]/(2.0*n*n);
573
574 if (std::fabs(dum) < 1.0) {
575 if( test >= 1.0e-10 )excs += dum*test;
576 } else {
577 excs += dum*test;
578 }
579
580 if (ran < excs) goto outOfLoopAn; //----------------------->
581 }
582 }
583 }
584 }
585 // 3 previous loops continued to the end
586 inElastic = false; // quasi-elastic scattering
587 return;
588
589 } else { // target must be a neutron
590 counter = -1;
591 for (np=0; np<numSec/3; np++) {
592 nm = np;
593 for (nz=0; nz<numSec/3; nz++) {
594 if (++counter < numMulAn) {
595 nt = np+nm+nz;
596 if ( (nt>1) && (nt<=numSec) ) {
597 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
598 dum = (pi/anpn)*nt*neutmulAn[counter]*neutnormAn[nt-1]/(2.0*n*n);
599
600 if (std::fabs(dum) < 1.0) {
601 if( test >= 1.0e-10 )excs += dum*test;
602 } else {
603 excs += dum*test;
604 }
605
606 if (ran < excs) goto outOfLoopAn; // -------------------------->
607 }
608 }
609 }
610 }
611 inElastic = false; // quasi-elastic scattering.
612 return;
613 }
614 outOfLoopAn: // <------------------------------------------------------------------
615 vecLen = 0;
616 }
617 }
618
619 nt = np + nm + nz;
620 while ( nt > 0)
621 {
622 G4double ran = G4UniformRand();
623 if ( ran < (G4double)np/nt)
624 {
625 if( np > 0 )
626 { pv[vecLen++] = PionPlus;
627 np--;
628 }
629 }
630 else if ( ran < (G4double)(np+nm)/nt)
631 {
632 if( nm > 0 )
633 {
634 pv[vecLen++] = PionMinus;
635 nm--;
636 }
637 }
638 else
639 {
640 if( nz > 0 )
641 {
642 pv[vecLen++] = PionZero;
643 nz--;
644 }
645 }
646 nt = np + nm + nz;
647 }
648 if (verboseLevel > 1)
649 {
650 G4cout << "Particles produced: " ;
651 G4cout << pv[0].getName() << " " ;
652 G4cout << pv[1].getName() << " " ;
653 for (i=2; i < vecLen; i++)
654 {
655 G4cout << pv[i].getName() << " " ;
656 }
657 G4cout << G4endl;
658 }
659 return;
660 }
661
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