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G4DiffuseElastic.hh
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27 // $Id$
28 //
29 // Author: V. Grichine (Vladimir,Grichine@cern.ch)
30 //
31 //
32 // G4 Model: diffuse optical elastic scattering with 4-momentum balance
33 //
34 // Class Description
35 // Final state production model for hadron nuclear elastic scattering;
36 // Class Description - End
37 //
38 //
39 // 24.05.07 V. Grichine, first implementation for hadron (no Coulomb) elastic scattering
40 // 04.09.07 V. Grichine, implementation for Coulomb elastic scattering
41 // 12.06.11 V. Grichine, new interface to G4hadronElastic
42 
43 #ifndef G4DiffuseElastic_h
44 #define G4DiffuseElastic_h 1
45 
46 #include <CLHEP/Units/PhysicalConstants.h>
47 #include "globals.hh"
48 #include "G4HadronElastic.hh"
49 #include "G4HadProjectile.hh"
50 #include "G4Nucleus.hh"
51 
52 using namespace std;
53 
54 class G4ParticleDefinition;
55 class G4PhysicsTable;
56 class G4PhysicsLogVector;
57 
58 class G4DiffuseElastic : public G4HadronElastic // G4HadronicInteraction
59 {
60 public:
61 
62  G4DiffuseElastic();
63 
64  // G4DiffuseElastic(const G4ParticleDefinition* aParticle);
65 
66 
67 
68 
69 
70  virtual ~G4DiffuseElastic();
71 
72  void Initialise();
73 
74  void InitialiseOnFly(G4double Z, G4double A);
75 
76  void BuildAngleTable();
77 
78 
79  // G4HadFinalState* ApplyYourself(const G4HadProjectile & aTrack, G4Nucleus & targetNucleus);
80 
81  virtual G4double SampleInvariantT(const G4ParticleDefinition* p,
82  G4double plab,
83  G4int Z, G4int A);
84 
85  void SetPlabLowLimit(G4double value);
86 
87  void SetHEModelLowLimit(G4double value);
88 
89  void SetQModelLowLimit(G4double value);
90 
91  void SetLowestEnergyLimit(G4double value);
92 
93  void SetRecoilKinEnergyLimit(G4double value);
94 
95  G4double SampleT(const G4ParticleDefinition* aParticle,
96  G4double p, G4double A);
97 
98  G4double SampleTableT(const G4ParticleDefinition* aParticle,
99  G4double p, G4double Z, G4double A);
100 
101  G4double SampleThetaCMS(const G4ParticleDefinition* aParticle, G4double p, G4double A);
102 
103  G4double SampleTableThetaCMS(const G4ParticleDefinition* aParticle, G4double p,
104  G4double Z, G4double A);
105 
106  G4double GetScatteringAngle(G4int iMomentum, G4int iAngle, G4double position);
107 
108  G4double SampleThetaLab(const G4HadProjectile* aParticle,
109  G4double tmass, G4double A);
110 
111  G4double GetDiffuseElasticXsc( const G4ParticleDefinition* particle,
112  G4double theta,
113  G4double momentum,
114  G4double A );
115 
116  G4double GetInvElasticXsc( const G4ParticleDefinition* particle,
117  G4double theta,
118  G4double momentum,
119  G4double A, G4double Z );
120 
121  G4double GetDiffuseElasticSumXsc( const G4ParticleDefinition* particle,
122  G4double theta,
123  G4double momentum,
124  G4double A, G4double Z );
125 
126  G4double GetInvElasticSumXsc( const G4ParticleDefinition* particle,
127  G4double tMand,
128  G4double momentum,
129  G4double A, G4double Z );
130 
131  G4double IntegralElasticProb( const G4ParticleDefinition* particle,
132  G4double theta,
133  G4double momentum,
134  G4double A );
135 
136 
137  G4double GetCoulombElasticXsc( const G4ParticleDefinition* particle,
138  G4double theta,
139  G4double momentum,
140  G4double Z );
141 
142  G4double GetInvCoulombElasticXsc( const G4ParticleDefinition* particle,
143  G4double tMand,
144  G4double momentum,
145  G4double A, G4double Z );
146 
147  G4double GetCoulombTotalXsc( const G4ParticleDefinition* particle,
148  G4double momentum, G4double Z );
149 
150  G4double GetCoulombIntegralXsc( const G4ParticleDefinition* particle,
151  G4double momentum, G4double Z,
152  G4double theta1, G4double theta2 );
153 
154 
155  G4double CalculateParticleBeta( const G4ParticleDefinition* particle,
156  G4double momentum );
157 
158  G4double CalculateZommerfeld( G4double beta, G4double Z1, G4double Z2 );
159 
160  G4double CalculateAm( G4double momentum, G4double n, G4double Z);
161 
162  G4double CalculateNuclearRad( G4double A);
163 
164  G4double ThetaCMStoThetaLab(const G4DynamicParticle* aParticle,
165  G4double tmass, G4double thetaCMS);
166 
167  G4double ThetaLabToThetaCMS(const G4DynamicParticle* aParticle,
168  G4double tmass, G4double thetaLab);
169 
170  void TestAngleTable(const G4ParticleDefinition* theParticle, G4double partMom,
171  G4double Z, G4double A);
172 
173 
174 
175  G4double BesselJzero(G4double z);
176  G4double BesselJone(G4double z);
177  G4double DampFactor(G4double z);
178  G4double BesselOneByArg(G4double z);
179 
180  G4double GetDiffElasticProb(G4double theta);
181  G4double GetDiffElasticSumProb(G4double theta);
182  G4double GetDiffElasticSumProbA(G4double alpha);
183  G4double GetIntegrandFunction(G4double theta);
184 
185 
186  G4double GetNuclearRadius(){return fNuclearRadius;};
187 
188 private:
189 
190 
191  G4ParticleDefinition* theProton;
192  G4ParticleDefinition* theNeutron;
193  G4ParticleDefinition* theDeuteron;
194  G4ParticleDefinition* theAlpha;
195 
196  const G4ParticleDefinition* thePionPlus;
197  const G4ParticleDefinition* thePionMinus;
198 
199  G4double lowEnergyRecoilLimit;
200  G4double lowEnergyLimitHE;
201  G4double lowEnergyLimitQ;
202  G4double lowestEnergyLimit;
203  G4double plabLowLimit;
204 
205  G4int fEnergyBin;
206  G4int fAngleBin;
207 
208  G4PhysicsLogVector* fEnergyVector;
209  G4PhysicsTable* fAngleTable;
210  std::vector<G4PhysicsTable*> fAngleBank;
211 
212  std::vector<G4double> fElementNumberVector;
213  std::vector<G4String> fElementNameVector;
214 
215  const G4ParticleDefinition* fParticle;
216  G4double fWaveVector;
217  G4double fAtomicWeight;
218  G4double fAtomicNumber;
219  G4double fNuclearRadius;
220  G4double fBeta;
221  G4double fZommerfeld;
222  G4double fAm;
223  G4bool fAddCoulomb;
224 
225 };
226 
227 
228 inline void G4DiffuseElastic::SetRecoilKinEnergyLimit(G4double value)
229 {
230  lowEnergyRecoilLimit = value;
231 }
232 
233 inline void G4DiffuseElastic::SetPlabLowLimit(G4double value)
234 {
235  plabLowLimit = value;
236 }
237 
238 inline void G4DiffuseElastic::SetHEModelLowLimit(G4double value)
239 {
240  lowEnergyLimitHE = value;
241 }
242 
243 inline void G4DiffuseElastic::SetQModelLowLimit(G4double value)
244 {
245  lowEnergyLimitQ = value;
246 }
247 
248 inline void G4DiffuseElastic::SetLowestEnergyLimit(G4double value)
249 {
250  lowestEnergyLimit = value;
251 }
252 
253 
255 //
256 // Bessel J0 function based on rational approximation from
257 // J.F. Hart, Computer Approximations, New York, Willey 1968, p. 141
258 
259 inline G4double G4DiffuseElastic::BesselJzero(G4double value)
260 {
261  G4double modvalue, value2, fact1, fact2, arg, shift, bessel;
262 
263  modvalue = fabs(value);
264 
265  if ( value < 8.0 && value > -8.0 )
266  {
267  value2 = value*value;
268 
269  fact1 = 57568490574.0 + value2*(-13362590354.0
270  + value2*( 651619640.7
271  + value2*(-11214424.18
272  + value2*( 77392.33017
273  + value2*(-184.9052456 ) ) ) ) );
274 
275  fact2 = 57568490411.0 + value2*( 1029532985.0
276  + value2*( 9494680.718
277  + value2*(59272.64853
278  + value2*(267.8532712
279  + value2*1.0 ) ) ) );
280 
281  bessel = fact1/fact2;
282  }
283  else
284  {
285  arg = 8.0/modvalue;
286 
287  value2 = arg*arg;
288 
289  shift = modvalue-0.785398164;
290 
291  fact1 = 1.0 + value2*(-0.1098628627e-2
292  + value2*(0.2734510407e-4
293  + value2*(-0.2073370639e-5
294  + value2*0.2093887211e-6 ) ) );
295 
296  fact2 = -0.1562499995e-1 + value2*(0.1430488765e-3
297  + value2*(-0.6911147651e-5
298  + value2*(0.7621095161e-6
299  - value2*0.934945152e-7 ) ) );
300 
301  bessel = sqrt(0.636619772/modvalue)*(cos(shift)*fact1 - arg*sin(shift)*fact2 );
302  }
303  return bessel;
304 }
305 
307 //
308 // Bessel J1 function based on rational approximation from
309 // J.F. Hart, Computer Approximations, New York, Willey 1968, p. 141
310 
311 inline G4double G4DiffuseElastic::BesselJone(G4double value)
312 {
313  G4double modvalue, value2, fact1, fact2, arg, shift, bessel;
314 
315  modvalue = fabs(value);
316 
317  if ( modvalue < 8.0 )
318  {
319  value2 = value*value;
320 
321  fact1 = value*(72362614232.0 + value2*(-7895059235.0
322  + value2*( 242396853.1
323  + value2*(-2972611.439
324  + value2*( 15704.48260
325  + value2*(-30.16036606 ) ) ) ) ) );
326 
327  fact2 = 144725228442.0 + value2*(2300535178.0
328  + value2*(18583304.74
329  + value2*(99447.43394
330  + value2*(376.9991397
331  + value2*1.0 ) ) ) );
332  bessel = fact1/fact2;
333  }
334  else
335  {
336  arg = 8.0/modvalue;
337 
338  value2 = arg*arg;
339 
340  shift = modvalue - 2.356194491;
341 
342  fact1 = 1.0 + value2*( 0.183105e-2
343  + value2*(-0.3516396496e-4
344  + value2*(0.2457520174e-5
345  + value2*(-0.240337019e-6 ) ) ) );
346 
347  fact2 = 0.04687499995 + value2*(-0.2002690873e-3
348  + value2*( 0.8449199096e-5
349  + value2*(-0.88228987e-6
350  + value2*0.105787412e-6 ) ) );
351 
352  bessel = sqrt( 0.636619772/modvalue)*(cos(shift)*fact1 - arg*sin(shift)*fact2);
353 
354  if (value < 0.0) bessel = -bessel;
355  }
356  return bessel;
357 }
358 
360 //
361 // damp factor in diffraction x/sh(x), x was already *pi
362 
363 inline G4double G4DiffuseElastic::DampFactor(G4double x)
364 {
365  G4double df;
366  G4double f2 = 2., f3 = 6., f4 = 24.; // first factorials
367 
368  // x *= pi;
369 
370  if( std::fabs(x) < 0.01 )
371  {
372  df = 1./(1. + x/f2 + x*x/f3 + x*x*x/f4);
373  }
374  else
375  {
376  df = x/std::sinh(x);
377  }
378  return df;
379 }
380 
381 
383 //
384 // return J1(x)/x with special case for small x
385 
386 inline G4double G4DiffuseElastic::BesselOneByArg(G4double x)
387 {
388  G4double x2, result;
389 
390  if( std::fabs(x) < 0.01 )
391  {
392  x *= 0.5;
393  x2 = x*x;
394  result = 2. - x2 + x2*x2/6.;
395  }
396  else
397  {
398  result = BesselJone(x)/x;
399  }
400  return result;
401 }
402 
404 //
405 // return particle beta
406 
407 inline G4double G4DiffuseElastic::CalculateParticleBeta( const G4ParticleDefinition* particle,
408  G4double momentum )
409 {
410  G4double mass = particle->GetPDGMass();
411  G4double a = momentum/mass;
412  fBeta = a/std::sqrt(1+a*a);
413 
414  return fBeta;
415 }
416 
418 //
419 // return Zommerfeld parameter for Coulomb scattering
420 
421 inline G4double G4DiffuseElastic::CalculateZommerfeld( G4double beta, G4double Z1, G4double Z2 )
422 {
423  fZommerfeld = CLHEP::fine_structure_const*Z1*Z2/beta;
424 
425  return fZommerfeld;
426 }
427 
429 //
430 // return Wentzel correction for Coulomb scattering
431 
432 inline G4double G4DiffuseElastic::CalculateAm( G4double momentum, G4double n, G4double Z)
433 {
434  G4double k = momentum/CLHEP::hbarc;
435  G4double ch = 1.13 + 3.76*n*n;
436  G4double zn = 1.77*k*std::pow(Z,-1./3.)*CLHEP::Bohr_radius;
437  G4double zn2 = zn*zn;
438  fAm = ch/zn2;
439 
440  return fAm;
441 }
442 
444 //
445 // calculate nuclear radius for different atomic weights using different approximations
446 
447 inline G4double G4DiffuseElastic::CalculateNuclearRad( G4double A)
448 {
449  G4double r0;
450 
451  if( A < 50. )
452  {
453  if( A > 10. ) r0 = 1.16*( 1 - std::pow(A, -2./3.) )*CLHEP::fermi; // 1.08*fermi;
454  else r0 = 1.1*CLHEP::fermi;
455 
456  fNuclearRadius = r0*std::pow(A, 1./3.);
457  }
458  else
459  {
460  r0 = 1.7*CLHEP::fermi; // 1.7*fermi;
461 
462  fNuclearRadius = r0*std::pow(A, 0.27); // 0.27);
463  }
464  return fNuclearRadius;
465 }
466 
468 //
469 // return Coulomb scattering differential xsc with Wentzel correction
470 
471 inline G4double G4DiffuseElastic::GetCoulombElasticXsc( const G4ParticleDefinition* particle,
472  G4double theta,
473  G4double momentum,
474  G4double Z )
475 {
476  G4double sinHalfTheta = std::sin(0.5*theta);
477  G4double sinHalfTheta2 = sinHalfTheta*sinHalfTheta;
478  G4double beta = CalculateParticleBeta( particle, momentum);
479  G4double z = particle->GetPDGCharge();
480  G4double n = CalculateZommerfeld( beta, z, Z );
481  G4double am = CalculateAm( momentum, n, Z);
482  G4double k = momentum/CLHEP::hbarc;
483  G4double ch = 0.5*n/k;
484  G4double ch2 = ch*ch;
485  G4double xsc = ch2/(sinHalfTheta2+am)/(sinHalfTheta2+am);
486 
487  return xsc;
488 }
489 
490 
492 //
493 // return Coulomb scattering total xsc with Wentzel correction
494 
495 inline G4double G4DiffuseElastic::GetCoulombTotalXsc( const G4ParticleDefinition* particle,
496  G4double momentum, G4double Z )
497 {
498  G4double beta = CalculateParticleBeta( particle, momentum);
499  G4cout<<"beta = "<<beta<<G4endl;
500  G4double z = particle->GetPDGCharge();
501  G4double n = CalculateZommerfeld( beta, z, Z );
502  G4cout<<"fZomerfeld = "<<n<<G4endl;
503  G4double am = CalculateAm( momentum, n, Z);
504  G4cout<<"cof Am = "<<am<<G4endl;
505  G4double k = momentum/CLHEP::hbarc;
506  G4cout<<"k = "<<k*CLHEP::fermi<<" 1/fermi"<<G4endl;
507  G4cout<<"k*Bohr_radius = "<<k*CLHEP::Bohr_radius<<G4endl;
508  G4double ch = n/k;
509  G4double ch2 = ch*ch;
510  G4double xsc = ch2*CLHEP::pi/(am +am*am);
511 
512  return xsc;
513 }
514 
516 //
517 // return Coulomb scattering xsc with Wentzel correction integrated between
518 // theta1 and < theta2
519 
520 inline G4double G4DiffuseElastic::GetCoulombIntegralXsc( const G4ParticleDefinition* particle,
521  G4double momentum, G4double Z,
522  G4double theta1, G4double theta2 )
523 {
524  G4double c1 = std::cos(theta1);
525  G4cout<<"c1 = "<<c1<<G4endl;
526  G4double c2 = std::cos(theta2);
527  G4cout<<"c2 = "<<c2<<G4endl;
528  G4double beta = CalculateParticleBeta( particle, momentum);
529  // G4cout<<"beta = "<<beta<<G4endl;
530  G4double z = particle->GetPDGCharge();
531  G4double n = CalculateZommerfeld( beta, z, Z );
532  // G4cout<<"fZomerfeld = "<<n<<G4endl;
533  G4double am = CalculateAm( momentum, n, Z);
534  // G4cout<<"cof Am = "<<am<<G4endl;
535  G4double k = momentum/CLHEP::hbarc;
536  // G4cout<<"k = "<<k*CLHEP::fermi<<" 1/fermi"<<G4endl;
537  // G4cout<<"k*Bohr_radius = "<<k*CLHEP::Bohr_radius<<G4endl;
538  G4double ch = n/k;
539  G4double ch2 = ch*ch;
540  am *= 2.;
541  G4double xsc = ch2*CLHEP::twopi*(c1-c2);
542  xsc /= (1 - c1 + am)*(1 - c2 + am);
543 
544  return xsc;
545 }
546 
547 #endif
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