source: trunk/source/processes/hadronic/models/coherent_elastic/include/G4DiffuseElastic.hh@ 1199

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1//
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17// * *
18// * This code implementation is the result of the scientific and *
19// * technical work of the GEANT4 collaboration. *
20// * By using, copying, modifying or distributing the software (or *
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25//
26//
27// $Id: G4DiffuseElastic.hh,v 1.17 2009/09/22 16:21:46 vnivanch Exp $
28// GEANT4 tag $Name: geant4-09-03-cand-01 $
29//
30//
31// G4 Model: optical elastic scattering with 4-momentum balance
32//
33// Class Description
34// Final state production model for hadron nuclear elastic scattering;
35// Class Description - End
36//
37//
38// 24.05.07 V. Grichine first implementation for hadron (no Coulomb) elastic scattering
39// 04.09.07 V. Grichine implementation for Coulomb elastic scattering
40
41
42#ifndef G4DiffuseElastic_h
43#define G4DiffuseElastic_h 1
44
45#include "globals.hh"
46#include "G4HadronicInteraction.hh"
47#include "G4HadProjectile.hh"
48#include "G4Nucleus.hh"
49
50using namespace std;
51
52class G4ParticleDefinition;
53class G4PhysicsTable;
54class G4PhysicsLogVector;
55
56class G4DiffuseElastic : public G4HadronicInteraction
57{
58public:
59
60 G4DiffuseElastic();
61
62 G4DiffuseElastic(const G4ParticleDefinition* aParticle);
63
64
65
66
67
68 virtual ~G4DiffuseElastic();
69
70 void Initialise();
71
72 void InitialiseOnFly(G4double Z, G4double A);
73
74 void BuildAngleTable();
75
76
77 G4HadFinalState * ApplyYourself(const G4HadProjectile & aTrack,
78 G4Nucleus & targetNucleus);
79
80
81 void SetPlabLowLimit(G4double value);
82
83 void SetHEModelLowLimit(G4double value);
84
85 void SetQModelLowLimit(G4double value);
86
87 void SetLowestEnergyLimit(G4double value);
88
89 void SetRecoilKinEnergyLimit(G4double value);
90
91 G4double SampleT(const G4ParticleDefinition* aParticle,
92 G4double p, G4double A);
93
94 G4double SampleTableT(const G4ParticleDefinition* aParticle,
95 G4double p, G4double Z, G4double A);
96
97 G4double SampleThetaCMS(const G4ParticleDefinition* aParticle, G4double p, G4double A);
98
99 G4double SampleTableThetaCMS(const G4ParticleDefinition* aParticle, G4double p,
100 G4double Z, G4double A);
101
102 G4double GetScatteringAngle(G4int iMomentum, G4int iAngle, G4double position);
103
104 G4double SampleThetaLab(const G4HadProjectile* aParticle,
105 G4double tmass, G4double A);
106
107 G4double GetDiffuseElasticXsc( const G4ParticleDefinition* particle,
108 G4double theta,
109 G4double momentum,
110 G4double A );
111
112 G4double GetInvElasticXsc( const G4ParticleDefinition* particle,
113 G4double theta,
114 G4double momentum,
115 G4double A, G4double Z );
116
117 G4double GetDiffuseElasticSumXsc( const G4ParticleDefinition* particle,
118 G4double theta,
119 G4double momentum,
120 G4double A, G4double Z );
121
122 G4double GetInvElasticSumXsc( const G4ParticleDefinition* particle,
123 G4double tMand,
124 G4double momentum,
125 G4double A, G4double Z );
126
127 G4double IntegralElasticProb( const G4ParticleDefinition* particle,
128 G4double theta,
129 G4double momentum,
130 G4double A );
131
132
133 G4double GetCoulombElasticXsc( const G4ParticleDefinition* particle,
134 G4double theta,
135 G4double momentum,
136 G4double Z );
137
138 G4double GetInvCoulombElasticXsc( const G4ParticleDefinition* particle,
139 G4double tMand,
140 G4double momentum,
141 G4double A, G4double Z );
142
143 G4double GetCoulombTotalXsc( const G4ParticleDefinition* particle,
144 G4double momentum, G4double Z );
145
146 G4double GetCoulombIntegralXsc( const G4ParticleDefinition* particle,
147 G4double momentum, G4double Z,
148 G4double theta1, G4double theta2 );
149
150
151 G4double CalculateParticleBeta( const G4ParticleDefinition* particle,
152 G4double momentum );
153
154 G4double CalculateZommerfeld( G4double beta, G4double Z1, G4double Z2 );
155
156 G4double CalculateAm( G4double momentum, G4double n, G4double Z);
157
158 G4double CalculateNuclearRad( G4double A);
159
160 G4double ThetaCMStoThetaLab(const G4DynamicParticle* aParticle,
161 G4double tmass, G4double thetaCMS);
162
163 G4double ThetaLabToThetaCMS(const G4DynamicParticle* aParticle,
164 G4double tmass, G4double thetaLab);
165
166 void TestAngleTable(const G4ParticleDefinition* theParticle, G4double partMom,
167 G4double Z, G4double A);
168
169
170
171 G4double BesselJzero(G4double z);
172 G4double BesselJone(G4double z);
173 G4double DampFactor(G4double z);
174 G4double BesselOneByArg(G4double z);
175
176 G4double GetDiffElasticProb(G4double theta);
177 G4double GetDiffElasticSumProb(G4double theta);
178 G4double GetDiffElasticSumProbA(G4double alpha);
179 G4double GetIntegrandFunction(G4double theta);
180
181
182 G4double GetNuclearRadius(){return fNuclearRadius;};
183
184private:
185
186
187 G4ParticleDefinition* theProton;
188 G4ParticleDefinition* theNeutron;
189 G4ParticleDefinition* theDeuteron;
190 G4ParticleDefinition* theAlpha;
191
192 const G4ParticleDefinition* thePionPlus;
193 const G4ParticleDefinition* thePionMinus;
194
195 G4double lowEnergyRecoilLimit;
196 G4double lowEnergyLimitHE;
197 G4double lowEnergyLimitQ;
198 G4double lowestEnergyLimit;
199 G4double plabLowLimit;
200
201 G4int fEnergyBin;
202 G4int fAngleBin;
203
204 G4PhysicsLogVector* fEnergyVector;
205 G4PhysicsTable* fAngleTable;
206 std::vector<G4PhysicsTable*> fAngleBank;
207
208 std::vector<G4double> fElementNumberVector;
209 std::vector<G4String> fElementNameVector;
210
211 const G4ParticleDefinition* fParticle;
212 G4double fWaveVector;
213 G4double fAtomicWeight;
214 G4double fAtomicNumber;
215 G4double fNuclearRadius;
216 G4double fBeta;
217 G4double fZommerfeld;
218 G4double fAm;
219 G4bool fAddCoulomb;
220
221};
222
223
224inline void G4DiffuseElastic::SetRecoilKinEnergyLimit(G4double value)
225{
226 lowEnergyRecoilLimit = value;
227}
228
229inline void G4DiffuseElastic::SetPlabLowLimit(G4double value)
230{
231 plabLowLimit = value;
232}
233
234inline void G4DiffuseElastic::SetHEModelLowLimit(G4double value)
235{
236 lowEnergyLimitHE = value;
237}
238
239inline void G4DiffuseElastic::SetQModelLowLimit(G4double value)
240{
241 lowEnergyLimitQ = value;
242}
243
244inline void G4DiffuseElastic::SetLowestEnergyLimit(G4double value)
245{
246 lowestEnergyLimit = value;
247}
248
249
250/////////////////////////////////////////////////////////////
251//
252// Bessel J0 function based on rational approximation from
253// J.F. Hart, Computer Approximations, New York, Willey 1968, p. 141
254
255inline G4double G4DiffuseElastic::BesselJzero(G4double value)
256{
257 G4double modvalue, value2, fact1, fact2, arg, shift, bessel;
258
259 modvalue = fabs(value);
260
261 if ( value < 8.0 && value > -8.0 )
262 {
263 value2 = value*value;
264
265 fact1 = 57568490574.0 + value2*(-13362590354.0
266 + value2*( 651619640.7
267 + value2*(-11214424.18
268 + value2*( 77392.33017
269 + value2*(-184.9052456 ) ) ) ) );
270
271 fact2 = 57568490411.0 + value2*( 1029532985.0
272 + value2*( 9494680.718
273 + value2*(59272.64853
274 + value2*(267.8532712
275 + value2*1.0 ) ) ) );
276
277 bessel = fact1/fact2;
278 }
279 else
280 {
281 arg = 8.0/modvalue;
282
283 value2 = arg*arg;
284
285 shift = modvalue-0.785398164;
286
287 fact1 = 1.0 + value2*(-0.1098628627e-2
288 + value2*(0.2734510407e-4
289 + value2*(-0.2073370639e-5
290 + value2*0.2093887211e-6 ) ) );
291
292 fact2 = -0.1562499995e-1 + value2*(0.1430488765e-3
293 + value2*(-0.6911147651e-5
294 + value2*(0.7621095161e-6
295 - value2*0.934945152e-7 ) ) );
296
297 bessel = sqrt(0.636619772/modvalue)*(cos(shift)*fact1 - arg*sin(shift)*fact2 );
298 }
299 return bessel;
300}
301
302/////////////////////////////////////////////////////////////
303//
304// Bessel J1 function based on rational approximation from
305// J.F. Hart, Computer Approximations, New York, Willey 1968, p. 141
306
307inline G4double G4DiffuseElastic::BesselJone(G4double value)
308{
309 G4double modvalue, value2, fact1, fact2, arg, shift, bessel;
310
311 modvalue = fabs(value);
312
313 if ( modvalue < 8.0 )
314 {
315 value2 = value*value;
316
317 fact1 = value*(72362614232.0 + value2*(-7895059235.0
318 + value2*( 242396853.1
319 + value2*(-2972611.439
320 + value2*( 15704.48260
321 + value2*(-30.16036606 ) ) ) ) ) );
322
323 fact2 = 144725228442.0 + value2*(2300535178.0
324 + value2*(18583304.74
325 + value2*(99447.43394
326 + value2*(376.9991397
327 + value2*1.0 ) ) ) );
328 bessel = fact1/fact2;
329 }
330 else
331 {
332 arg = 8.0/modvalue;
333
334 value2 = arg*arg;
335
336 shift = modvalue - 2.356194491;
337
338 fact1 = 1.0 + value2*( 0.183105e-2
339 + value2*(-0.3516396496e-4
340 + value2*(0.2457520174e-5
341 + value2*(-0.240337019e-6 ) ) ) );
342
343 fact2 = 0.04687499995 + value2*(-0.2002690873e-3
344 + value2*( 0.8449199096e-5
345 + value2*(-0.88228987e-6
346 + value2*0.105787412e-6 ) ) );
347
348 bessel = sqrt( 0.636619772/modvalue)*(cos(shift)*fact1 - arg*sin(shift)*fact2);
349
350 if (value < 0.0) bessel = -bessel;
351 }
352 return bessel;
353}
354
355////////////////////////////////////////////////////////////////////
356//
357// damp factor in diffraction x/sh(x), x was already *pi
358
359inline G4double G4DiffuseElastic::DampFactor(G4double x)
360{
361 G4double df;
362 G4double f2 = 2., f3 = 6., f4 = 24.; // first factorials
363
364 // x *= pi;
365
366 if( std::fabs(x) < 0.01 )
367 {
368 df = 1./(1. + x/f2 + x*x/f3 + x*x*x/f4);
369 }
370 else
371 {
372 df = x/std::sinh(x);
373 }
374 return df;
375}
376
377
378////////////////////////////////////////////////////////////////////
379//
380// return J1(x)/x with special case for small x
381
382inline G4double G4DiffuseElastic::BesselOneByArg(G4double x)
383{
384 G4double x2, result;
385
386 if( std::fabs(x) < 0.01 )
387 {
388 x *= 0.5;
389 x2 = x*x;
390 result = 2. - x2 + x2*x2/6.;
391 }
392 else
393 {
394 result = BesselJone(x)/x;
395 }
396 return result;
397}
398
399////////////////////////////////////////////////////////////////////
400//
401// return particle beta
402
403inline G4double G4DiffuseElastic::CalculateParticleBeta( const G4ParticleDefinition* particle,
404 G4double momentum )
405{
406 G4double mass = particle->GetPDGMass();
407 G4double a = momentum/mass;
408 fBeta = a/std::sqrt(1+a*a);
409
410 return fBeta;
411}
412
413////////////////////////////////////////////////////////////////////
414//
415// return Zommerfeld parameter for Coulomb scattering
416
417inline G4double G4DiffuseElastic::CalculateZommerfeld( G4double beta, G4double Z1, G4double Z2 )
418{
419 fZommerfeld = fine_structure_const*Z1*Z2/beta;
420
421 return fZommerfeld;
422}
423
424////////////////////////////////////////////////////////////////////
425//
426// return Wentzel correction for Coulomb scattering
427
428inline G4double G4DiffuseElastic::CalculateAm( G4double momentum, G4double n, G4double Z)
429{
430 G4double k = momentum/hbarc;
431 G4double ch = 1.13 + 3.76*n*n;
432 G4double zn = 1.77*k*std::pow(Z,-1./3.)*Bohr_radius;
433 G4double zn2 = zn*zn;
434 fAm = ch/zn2;
435
436 return fAm;
437}
438
439////////////////////////////////////////////////////////////////////
440//
441// calculate nuclear radius for different atomic weights using different approximations
442
443inline G4double G4DiffuseElastic::CalculateNuclearRad( G4double A)
444{
445 G4double r0;
446
447 if( A < 50. )
448 {
449 if( A > 10. ) r0 = 1.16*( 1 - std::pow(A, -2./3.) )*fermi; // 1.08*fermi;
450 else r0 = 1.1*fermi;
451
452 fNuclearRadius = r0*std::pow(A, 1./3.);
453 }
454 else
455 {
456 r0 = 1.7*fermi; // 1.7*fermi;
457
458 fNuclearRadius = r0*std::pow(A, 0.27); // 0.27);
459 }
460 return fNuclearRadius;
461}
462
463////////////////////////////////////////////////////////////////////
464//
465// return Coulomb scattering differential xsc with Wentzel correction
466
467inline G4double G4DiffuseElastic::GetCoulombElasticXsc( const G4ParticleDefinition* particle,
468 G4double theta,
469 G4double momentum,
470 G4double Z )
471{
472 G4double sinHalfTheta = std::sin(0.5*theta);
473 G4double sinHalfTheta2 = sinHalfTheta*sinHalfTheta;
474 G4double beta = CalculateParticleBeta( particle, momentum);
475 G4double z = particle->GetPDGCharge();
476 G4double n = CalculateZommerfeld( beta, z, Z );
477 G4double am = CalculateAm( momentum, n, Z);
478 G4double k = momentum/hbarc;
479 G4double ch = 0.5*n/k;
480 G4double ch2 = ch*ch;
481 G4double xsc = ch2/(sinHalfTheta2+am)/(sinHalfTheta2+am);
482
483 return xsc;
484}
485
486
487////////////////////////////////////////////////////////////////////
488//
489// return Coulomb scattering total xsc with Wentzel correction
490
491inline G4double G4DiffuseElastic::GetCoulombTotalXsc( const G4ParticleDefinition* particle,
492 G4double momentum, G4double Z )
493{
494 G4double beta = CalculateParticleBeta( particle, momentum);
495 G4cout<<"beta = "<<beta<<G4endl;
496 G4double z = particle->GetPDGCharge();
497 G4double n = CalculateZommerfeld( beta, z, Z );
498 G4cout<<"fZomerfeld = "<<n<<G4endl;
499 G4double am = CalculateAm( momentum, n, Z);
500 G4cout<<"cof Am = "<<am<<G4endl;
501 G4double k = momentum/hbarc;
502 G4cout<<"k = "<<k*fermi<<" 1/fermi"<<G4endl;
503 G4cout<<"k*Bohr_radius = "<<k*Bohr_radius<<G4endl;
504 G4double ch = n/k;
505 G4double ch2 = ch*ch;
506 G4double xsc = ch2*pi/(am +am*am);
507
508 return xsc;
509}
510
511////////////////////////////////////////////////////////////////////
512//
513// return Coulomb scattering xsc with Wentzel correction integrated between
514// theta1 and < theta2
515
516inline G4double G4DiffuseElastic::GetCoulombIntegralXsc( const G4ParticleDefinition* particle,
517 G4double momentum, G4double Z,
518 G4double theta1, G4double theta2 )
519{
520 G4double c1 = std::cos(theta1);
521 G4cout<<"c1 = "<<c1<<G4endl;
522 G4double c2 = std::cos(theta2);
523 G4cout<<"c2 = "<<c2<<G4endl;
524 G4double beta = CalculateParticleBeta( particle, momentum);
525 // G4cout<<"beta = "<<beta<<G4endl;
526 G4double z = particle->GetPDGCharge();
527 G4double n = CalculateZommerfeld( beta, z, Z );
528 // G4cout<<"fZomerfeld = "<<n<<G4endl;
529 G4double am = CalculateAm( momentum, n, Z);
530 // G4cout<<"cof Am = "<<am<<G4endl;
531 G4double k = momentum/hbarc;
532 // G4cout<<"k = "<<k*fermi<<" 1/fermi"<<G4endl;
533 // G4cout<<"k*Bohr_radius = "<<k*Bohr_radius<<G4endl;
534 G4double ch = n/k;
535 G4double ch2 = ch*ch;
536 am *= 2.;
537 G4double xsc = ch2*twopi*(c1-c2);
538 xsc /= (1 - c1 + am)*(1 - c2 + am);
539
540 return xsc;
541}
542
543#endif
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