source: trunk/source/processes/hadronic/models/high_energy/src/G4HEKaonPlusInelastic.cc@ 1350

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

geant4 tag 9.4
File size: 18.8 KB
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25//
26// $Id: G4HEKaonPlusInelastic.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 "G4HEKaonPlusInelastic.hh"
43
44G4HadFinalState*
45G4HEKaonPlusInelastic::ApplyYourself(const G4HadProjectile& aTrack,
46 G4Nucleus& targetNucleus)
47{
48 G4HEVector* pv = new G4HEVector[MAXPART];
49 const G4HadProjectile* aParticle = &aTrack;
50 const G4double A = targetNucleus.GetN();
51 const G4double Z = targetNucleus.GetZ();
52 G4HEVector incidentParticle(aParticle);
53
54 G4double atomicNumber = Z;
55 G4double atomicWeight = A;
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 G4cout << "GHEKaonPlusInelastic: incident energy < 1 GeV" << G4endl;
65
66 if (verboseLevel > 1) {
67 G4cout << "G4HEKaonPlusInelastic::ApplyYourself" << G4endl;
68 G4cout << "incident particle " << incidentParticle.getName()
69 << "mass " << incidentMass
70 << "kinetic energy " << incidentKineticEnergy
71 << G4endl;
72 G4cout << "target material with (A,Z) = ("
73 << atomicWeight << "," << atomicNumber << ")" << G4endl;
74 }
75
76 G4double inelasticity = NuclearInelasticity(incidentKineticEnergy,
77 atomicWeight, atomicNumber);
78 if (verboseLevel > 1)
79 G4cout << "nuclear inelasticity = " << inelasticity << G4endl;
80
81 incidentKineticEnergy -= inelasticity;
82
83 G4double excitationEnergyGNP = 0.;
84 G4double excitationEnergyDTA = 0.;
85
86 G4double excitation = NuclearExcitation(incidentKineticEnergy,
87 atomicWeight, atomicNumber,
88 excitationEnergyGNP,
89 excitationEnergyDTA);
90 if (verboseLevel > 1)
91 G4cout << "nuclear excitation = " << excitation << excitationEnergyGNP
92 << excitationEnergyDTA << G4endl;
93
94 incidentKineticEnergy -= excitation;
95 incidentTotalEnergy = incidentKineticEnergy + incidentMass;
96 incidentTotalMomentum = std::sqrt( (incidentTotalEnergy-incidentMass)
97 *(incidentTotalEnergy+incidentMass));
98
99 G4HEVector targetParticle;
100
101 if (G4UniformRand() < atomicNumber/atomicWeight) {
102 targetParticle.setDefinition("Proton");
103 } else {
104 targetParticle.setDefinition("Neutron");
105 }
106
107 G4double targetMass = targetParticle.getMass();
108 G4double centerOfMassEnergy = std::sqrt(incidentMass*incidentMass
109 + targetMass*targetMass
110 + 2.0*targetMass*incidentTotalEnergy);
111 G4double availableEnergy = centerOfMassEnergy - targetMass - incidentMass;
112
113 G4bool inElastic = true;
114 vecLength = 0;
115
116 if (verboseLevel > 1)
117 G4cout << "ApplyYourself: CallFirstIntInCascade for particle "
118 << incidentCode << G4endl;
119
120 G4bool successful = false;
121
122 FirstIntInCasKaonPlus(inElastic, availableEnergy, pv, vecLength,
123 incidentParticle, targetParticle, atomicWeight);
124
125 if (verboseLevel > 1)
126 G4cout << "ApplyYourself::StrangeParticlePairProduction" << G4endl;
127
128 if ((vecLength > 0) && (availableEnergy > 1.))
129 StrangeParticlePairProduction(availableEnergy, centerOfMassEnergy,
130 pv, vecLength,
131 incidentParticle, targetParticle);
132
133 HighEnergyCascading(successful, pv, vecLength,
134 excitationEnergyGNP, excitationEnergyDTA,
135 incidentParticle, targetParticle,
136 atomicWeight, atomicNumber);
137 if (!successful)
138 HighEnergyClusterProduction(successful, pv, vecLength,
139 excitationEnergyGNP, excitationEnergyDTA,
140 incidentParticle, targetParticle,
141 atomicWeight, atomicNumber);
142 if (!successful)
143 MediumEnergyCascading(successful, pv, vecLength,
144 excitationEnergyGNP, excitationEnergyDTA,
145 incidentParticle, targetParticle,
146 atomicWeight, atomicNumber);
147
148 if (!successful)
149 MediumEnergyClusterProduction(successful, pv, vecLength,
150 excitationEnergyGNP, excitationEnergyDTA,
151 incidentParticle, targetParticle,
152 atomicWeight, atomicNumber);
153 if (!successful)
154 QuasiElasticScattering(successful, pv, vecLength,
155 excitationEnergyGNP, excitationEnergyDTA,
156 incidentParticle, targetParticle,
157 atomicWeight, atomicNumber);
158 if (!successful)
159 ElasticScattering(successful, pv, vecLength,
160 incidentParticle,
161 atomicWeight, atomicNumber);
162
163 if (!successful)
164 G4cout << "GHEInelasticInteraction::ApplyYourself fails to produce final state particles"
165 << G4endl;
166
167 FillParticleChange(pv, vecLength);
168 delete [] pv;
169 theParticleChange.SetStatusChange(stopAndKill);
170 return &theParticleChange;
171}
172
173
174void
175G4HEKaonPlusInelastic::FirstIntInCasKaonPlus(G4bool& inElastic,
176 const G4double availableEnergy,
177 G4HEVector pv[],
178 G4int& vecLen,
179 const G4HEVector& incidentParticle,
180 const G4HEVector& targetParticle,
181 const G4double atomicWeight)
182
183// Kaon+ undergoes interaction with nucleon within a nucleus. Check if it is
184// energetically possible to produce pions/kaons. In not, assume nuclear excitation
185// occurs and input particle is degraded in energy. No other particles are produced.
186// If reaction is possible, find the correct number of pions/protons/neutrons
187// produced using an interpolation to multiplicity data. Replace some pions or
188// protons/neutrons by kaons or strange baryons according to the average
189// multiplicity per inelastic reaction.
190{
191 static const G4double expxu = std::log(MAXFLOAT); // upper bound for arg. of exp
192 static const G4double expxl = -expxu; // lower bound for arg. of exp
193
194 static const G4double protb = 0.7;
195 static const G4double neutb = 0.7;
196 static const G4double c = 1.25;
197
198 static const G4int numMul = 1200;
199 static const G4int numSec = 60;
200
201 G4int neutronCode = Neutron.getCode();
202 G4int protonCode = Proton.getCode();
203
204 G4int targetCode = targetParticle.getCode();
205 G4double incidentTotalMomentum = incidentParticle.getTotalMomentum();
206
207 static G4bool first = true;
208 static G4double protmul[numMul], protnorm[numSec]; // proton constants
209 static G4double neutmul[numMul], neutnorm[numSec]; // neutron constants
210
211 // misc. local variables
212 // np = number of pi+, nm = number of pi-, nz = number of pi0
213
214 G4int i, counter, nt, np, nm, nz;
215
216 if( first )
217 { // compute normalization constants, this will only be done once
218 first = false;
219 for( i=0; i<numMul; i++ )protmul[i] = 0.0;
220 for( i=0; i<numSec; i++ )protnorm[i] = 0.0;
221 counter = -1;
222 for( np=0; np<(numSec/3); np++ )
223 {
224 for( nm=Imax(0,np-2); nm<=np; nm++ )
225 {
226 for( nz=0; nz<numSec/3; nz++ )
227 {
228 if( ++counter < numMul )
229 {
230 nt = np+nm+nz;
231 if( (nt>0) && (nt<=numSec) )
232 {
233 protmul[counter] =
234 pmltpc(np,nm,nz,nt,protb,c) ;
235 protnorm[nt-1] += protmul[counter];
236 }
237 }
238 }
239 }
240 }
241 for( i=0; i<numMul; i++ )neutmul[i] = 0.0;
242 for( i=0; i<numSec; i++ )neutnorm[i] = 0.0;
243 counter = -1;
244 for( np=0; np<numSec/3; np++ )
245 {
246 for( nm=Imax(0,np-1); nm<=(np+1); nm++ )
247 {
248 for( nz=0; nz<numSec/3; nz++ )
249 {
250 if( ++counter < numMul )
251 {
252 nt = np+nm+nz;
253 if( (nt>0) && (nt<=numSec) )
254 {
255 neutmul[counter] =
256 pmltpc(np,nm,nz,nt,neutb,c);
257 neutnorm[nt-1] += neutmul[counter];
258 }
259 }
260 }
261 }
262 }
263 for( i=0; i<numSec; i++ )
264 {
265 if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i];
266 if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i];
267 }
268 } // end of initialization
269
270
271 // initialize the first two places
272 // the same as beam and target
273 pv[0] = incidentParticle;
274 pv[1] = targetParticle;
275 vecLen = 2;
276
277 if( !inElastic )
278 { // quasi-elastic scattering, no pions produced
279 if( targetCode == neutronCode )
280 {
281 G4double cech[] = {0.33,0.27,0.29,0.31,0.27,0.18,0.13,0.10,0.09,0.07};
282 G4int iplab = G4int( Amin( 9.0, incidentTotalMomentum*5. ) );
283 if( G4UniformRand() < cech[iplab]/std::pow(atomicWeight,0.42) )
284 { // charge exchange K+ n -> K0 p
285 pv[0] = KaonZero;
286 pv[1] = Proton;
287 }
288 }
289 return;
290 }
291 else if (availableEnergy <= PionPlus.getMass())
292 return;
293
294 // inelastic scattering
295
296 np = 0, nm = 0, nz = 0;
297 G4double eab = availableEnergy;
298 G4int ieab = G4int( eab*5.0 );
299
300 G4double supp[] = {0., 0.4, 0.55, 0.65, 0.75, 0.82, 0.86, 0.90, 0.94, 0.98};
301 if( (ieab <= 9) && (G4UniformRand() >= supp[ieab]) )
302 {
303// suppress high multiplicity events at low momentum
304// only one additional pion will be produced
305 G4double w0, wp, wm, wt, ran;
306 if( targetCode == protonCode ) // target is a proton
307 {
308 w0 = - sqr(1.+protb)/(2.*c*c);
309 wp = w0 = std::exp(w0);
310 wp *= 2.;
311 if( G4UniformRand() < w0/(w0+wp) )
312 { np = 0; nm = 0; nz = 1; }
313 else
314 { np = 1; nm = 0; nz = 0; }
315 }
316 else
317 { // target is a neutron
318 w0 = -sqr(1.+neutb)/(2.*c*c);
319 wp = w0 = std::exp(w0);
320 wm = -sqr(-1.+neutb)/(2.*c*c);
321 wm = std::exp(wm);
322 wt = w0+wp+wm;
323 wp = w0+wp;
324 ran = G4UniformRand();
325 if( ran < w0/wt)
326 { np = 0; nm = 0; nz = 1; }
327 else if( ran < wp/wt)
328 { np = 1; nm = 0; nz = 0; }
329 else
330 { np = 0; nm = 1; nz = 0; }
331 }
332 }
333 else
334 {
335// number of total particles vs. centre of mass Energy - 2*proton mass
336
337 G4double aleab = std::log(availableEnergy);
338 G4double n = 3.62567+aleab*(0.665843+aleab*(0.336514
339 + aleab*(0.117712+0.0136912*aleab))) - 2.0;
340
341// normalization constant for kno-distribution.
342// calculate first the sum of all constants, check for numerical problems.
343 G4double test, dum, anpn = 0.0;
344
345 for (nt=1; nt<=numSec; nt++) {
346 test = std::exp( Amin( expxu, Amax( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
347 dum = pi*nt/(2.0*n*n);
348 if (std::fabs(dum) < 1.0) {
349 if( test >= 1.0e-10 )anpn += dum*test;
350 } else {
351 anpn += dum*test;
352 }
353 }
354
355 G4double ran = G4UniformRand();
356 G4double excs = 0.0;
357 if( targetCode == protonCode )
358 {
359 counter = -1;
360 for( np=0; np<numSec/3; np++ )
361 {
362 for( nm=Imax(0,np-2); nm<=np; nm++ )
363 {
364 for (nz=0; nz<numSec/3; nz++) {
365 if (++counter < numMul) {
366 nt = np+nm+nz;
367 if ( (nt>0) && (nt<=numSec) ) {
368 test = std::exp( Amin( expxu, Amax( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
369 dum = (pi/anpn)*nt*protmul[counter]*protnorm[nt-1]/(2.0*n*n);
370 if (std::fabs(dum) < 1.0) {
371 if( test >= 1.0e-10 )excs += dum*test;
372 } else {
373 excs += dum*test;
374 }
375 if (ran < excs) goto outOfLoop; //----------------------->
376 }
377 }
378 }
379 }
380 }
381
382 // 3 previous loops continued to the end
383 inElastic = false; // quasi-elastic scattering
384 return;
385 }
386 else
387 { // target must be a neutron
388 counter = -1;
389 for( np=0; np<numSec/3; np++ )
390 {
391 for( nm=Imax(0,np-1); nm<=(np+1); nm++ )
392 {
393 for (nz=0; nz<numSec/3; nz++) {
394 if (++counter < numMul) {
395 nt = np+nm+nz;
396 if ( (nt>=1) && (nt<=numSec) ) {
397 test = std::exp( Amin( expxu, Amax( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
398 dum = (pi/anpn)*nt*neutmul[counter]*neutnorm[nt-1]/(2.0*n*n);
399 if (std::fabs(dum) < 1.0) {
400 if( test >= 1.0e-10 )excs += dum*test;
401 } else {
402 excs += dum*test;
403 }
404 if (ran < excs) goto outOfLoop; // -------------------------->
405 }
406 }
407 }
408 }
409 }
410 // 3 previous loops continued to the end
411 inElastic = false; // quasi-elastic scattering.
412 return;
413 }
414 }
415 outOfLoop: // <------------------------------------------------------------------------
416
417 if( targetCode == protonCode)
418 {
419 if( np == nm)
420 {
421 }
422 else if (np == (1+nm))
423 {
424 if( G4UniformRand() < 0.5)
425 {
426 pv[1] = Neutron;
427 }
428 else
429 {
430 pv[0] = KaonZero;
431 }
432 }
433 else
434 {
435 pv[0] = KaonZero;
436 pv[1] = Neutron;
437 }
438 }
439 else
440 {
441 if( np == nm)
442 {
443 if( G4UniformRand() < 0.25)
444 {
445 pv[0] = KaonZero;
446 pv[1] = Proton;
447 }
448 else
449 {
450 }
451 }
452 else if ( np == (1+nm))
453 {
454 pv[0] = KaonZero;
455 }
456 else
457 {
458 pv[1] = Proton;
459 }
460 }
461
462
463 nt = np + nm + nz;
464 while ( nt > 0)
465 {
466 G4double ran = G4UniformRand();
467 if ( ran < (G4double)np/nt)
468 {
469 if( np > 0 )
470 { pv[vecLen++] = PionPlus;
471 np--;
472 }
473 }
474 else if ( ran < (G4double)(np+nm)/nt)
475 {
476 if( nm > 0 )
477 {
478 pv[vecLen++] = PionMinus;
479 nm--;
480 }
481 }
482 else
483 {
484 if( nz > 0 )
485 {
486 pv[vecLen++] = PionZero;
487 nz--;
488 }
489 }
490 nt = np + nm + nz;
491 }
492 if (verboseLevel > 1)
493 {
494 G4cout << "Particles produced: " ;
495 G4cout << pv[0].getName() << " " ;
496 G4cout << pv[1].getName() << " " ;
497 for (i=2; i < vecLen; i++)
498 {
499 G4cout << pv[i].getName() << " " ;
500 }
501 G4cout << G4endl;
502 }
503 return;
504 }
505
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