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25 //
26 //
27 //
28 // Author: V. Grichine (Vladimir,Grichine@cern.ch)
29 //
30 //
31 // G4 Model: diffuse 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 // 12.06.11 V. Grichine, new interface to G4hadronElastic
41 // 24.11.17 W. Pokorski, code cleanup and performance improvements
42
43
44 #ifndef G4DiffuseElasticV2_h
45 #define G4DiffuseElasticV2_h 1
46
47 #include <CLHEP/Units/PhysicalConstants.h>
48 #include "globals.hh"
49 #include "G4HadronElastic.hh"
50 #include "G4HadProjectile.hh"
51 #include "G4Nucleus.hh"
52
53 #include "G4Pow.hh"
54
55 #include <vector>
56
57 class G4ParticleDefinition;
58 class G4PhysicsTable;
59 class G4PhysicsLogVector;
60
61 class G4DiffuseElasticV2 : public G4HadronElastic // G4HadronicInteraction
62 {
63 public:
64
65 G4DiffuseElasticV2();
66
67 virtual ~G4DiffuseElasticV2();
68
69 virtual G4bool IsApplicable(const G4HadProjectile &/*aTrack*/,
70 G4Nucleus & /*targetNucleus*/);
71
72 void Initialise();
73
74 void InitialiseOnFly(G4double Z, G4double A);
75
76 void BuildAngleTable();
77
78 virtual G4double SampleInvariantT(const G4ParticleDefinition* p,
79 G4double plab,
80 G4int Z, G4int A);
81
82 G4double NeutronTuniform(G4int Z);
83
84 void SetPlabLowLimit(G4double value);
85
86 void SetHEModelLowLimit(G4double value);
87
88 void SetQModelLowLimit(G4double value);
89
90 void SetLowestEnergyLimit(G4double value);
91
92 void SetRecoilKinEnergyLimit(G4double value);
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, unsigned long iAngle, G4double position);
103
104 G4double SampleThetaLab(const G4HadProjectile* aParticle,
105 G4double tmass, G4double A);
106
107 G4double CalculateZommerfeld( G4double beta, G4double Z1, G4double Z2 );
108
109 G4double CalculateAm( G4double momentum, G4double n, G4double Z);
110
111 G4double CalculateNuclearRad( G4double A);
112
113 G4double ThetaCMStoThetaLab(const G4DynamicParticle* aParticle,
114 G4double tmass, G4double thetaCMS);
115
116 G4double ThetaLabToThetaCMS(const G4DynamicParticle* aParticle,
117 G4double tmass, G4double thetaLab);
118
119
120 G4double BesselJzero(G4double z);
121 G4double BesselJone(G4double z);
122 G4double DampFactor(G4double z);
123 G4double BesselOneByArg(G4double z);
124
125 G4double GetDiffElasticSumProbA(G4double alpha);
126 G4double GetIntegrandFunction(G4double theta);
127
128
129 G4double GetNuclearRadius(){return fNuclearRadius;};
130
131 private:
132
133
134 G4ParticleDefinition* theProton;
135 G4ParticleDefinition* theNeutron;
136
137 G4double lowEnergyRecoilLimit;
138 G4double lowEnergyLimitHE;
139 G4double lowEnergyLimitQ;
140 G4double lowestEnergyLimit;
141 G4double plabLowLimit;
142
143 G4int fEnergyBin;
144 unsigned long fAngleBin;
145
146 G4PhysicsLogVector* fEnergyVector;
147
148 std::vector<std::vector<std::vector<double>*>*> fEnergyAngleVectorBank;
149 std::vector<std::vector<std::vector<double>*>*> fEnergySumVectorBank;
150
151 std::vector<std::vector<double>*>* fEnergyAngleVector;
152 std::vector<std::vector<double>*>* fEnergySumVector;
153
154
155 std::vector<G4double> fElementNumberVector;
156 std::vector<G4String> fElementNameVector;
157
158 const G4ParticleDefinition* fParticle;
159 G4double fWaveVector;
160 G4double fAtomicWeight;
161 G4double fAtomicNumber;
162 G4double fNuclearRadius;
163 G4double fBeta;
164 G4double fZommerfeld;
165 G4double fAm;
166 G4bool fAddCoulomb;
167
168 };
169
170 inline G4bool G4DiffuseElasticV2::IsApplicable(const G4HadProjectile & projectile,
171 G4Nucleus & nucleus)
172 {
173 if( ( projectile.GetDefinition() == G4Proton::Proton() ||
174 projectile.GetDefinition() == G4Neutron::Neutron() ||
175 projectile.GetDefinition() == G4PionPlus::PionPlus() ||
176 projectile.GetDefinition() == G4PionMinus::PionMinus() ||
177 projectile.GetDefinition() == G4KaonPlus::KaonPlus() ||
178 projectile.GetDefinition() == G4KaonMinus::KaonMinus() ) &&
179
180 nucleus.GetZ_asInt() >= 2 ) return true;
181 else return false;
182 }
183
184 inline void G4DiffuseElasticV2::SetRecoilKinEnergyLimit(G4double value)
185 {
186 lowEnergyRecoilLimit = value;
187 }
188
189 inline void G4DiffuseElasticV2::SetPlabLowLimit(G4double value)
190 {
191 plabLowLimit = value;
192 }
193
194 inline void G4DiffuseElasticV2::SetHEModelLowLimit(G4double value)
195 {
196 lowEnergyLimitHE = value;
197 }
198
199 inline void G4DiffuseElasticV2::SetQModelLowLimit(G4double value)
200 {
201 lowEnergyLimitQ = value;
202 }
203
204 inline void G4DiffuseElasticV2::SetLowestEnergyLimit(G4double value)
205 {
206 lowestEnergyLimit = value;
207 }
208
209
210 /////////////////////////////////////////////////////////////
211 //
212 // Bessel J0 function based on rational approximation from
213 // J.F. Hart, Computer Approximations, New York, Willey 1968, p. 141
214
215 inline G4double G4DiffuseElasticV2::BesselJzero(G4double value)
216 {
217 G4double modvalue, value2, fact1, fact2, arg, shift, bessel;
218
219 modvalue = std::fabs(value);
220
221 if ( value < 8.0 && value > -8.0 )
222 {
223 value2 = value*value;
224
225 fact1 = 57568490574.0 + value2*(-13362590354.0
226 + value2*( 651619640.7
227 + value2*(-11214424.18
228 + value2*( 77392.33017
229 + value2*(-184.9052456 ) ) ) ) );
230
231 fact2 = 57568490411.0 + value2*( 1029532985.0
232 + value2*( 9494680.718
233 + value2*(59272.64853
234 + value2*(267.8532712
235 + value2*1.0 ) ) ) );
236
237 bessel = fact1/fact2;
238 }
239 else
240 {
241 arg = 8.0/modvalue;
242
243 value2 = arg*arg;
244
245 shift = modvalue-0.785398164;
246
247 fact1 = 1.0 + value2*(-0.1098628627e-2
248 + value2*(0.2734510407e-4
249 + value2*(-0.2073370639e-5
250 + value2*0.2093887211e-6 ) ) );
251
252 fact2 = -0.1562499995e-1 + value2*(0.1430488765e-3
253 + value2*(-0.6911147651e-5
254 + value2*(0.7621095161e-6
255 - value2*0.934945152e-7 ) ) );
256
257 bessel = std::sqrt(0.636619772/modvalue)*(std::cos(shift)*fact1 - arg*std::sin(shift)*fact2 );
258 }
259 return bessel;
260 }
261
262 /////////////////////////////////////////////////////////////
263 //
264 // Bessel J1 function based on rational approximation from
265 // J.F. Hart, Computer Approximations, New York, Willey 1968, p. 141
266
267 inline G4double G4DiffuseElasticV2::BesselJone(G4double value)
268 {
269 G4double modvalue, value2, fact1, fact2, arg, shift, bessel;
270
271 modvalue = std::fabs(value);
272
273 if ( modvalue < 8.0 )
274 {
275 value2 = value*value;
276
277 fact1 = value*(72362614232.0 + value2*(-7895059235.0
278 + value2*( 242396853.1
279 + value2*(-2972611.439
280 + value2*( 15704.48260
281 + value2*(-30.16036606 ) ) ) ) ) );
282
283 fact2 = 144725228442.0 + value2*(2300535178.0
284 + value2*(18583304.74
285 + value2*(99447.43394
286 + value2*(376.9991397
287 + value2*1.0 ) ) ) );
288 bessel = fact1/fact2;
289 }
290 else
291 {
292 arg = 8.0/modvalue;
293
294 value2 = arg*arg;
295
296 shift = modvalue - 2.356194491;
297
298 fact1 = 1.0 + value2*( 0.183105e-2
299 + value2*(-0.3516396496e-4
300 + value2*(0.2457520174e-5
301 + value2*(-0.240337019e-6 ) ) ) );
302
303 fact2 = 0.04687499995 + value2*(-0.2002690873e-3
304 + value2*( 0.8449199096e-5
305 + value2*(-0.88228987e-6
306 + value2*0.105787412e-6 ) ) );
307
308 bessel = std::sqrt( 0.636619772/modvalue)*(std::cos(shift)*fact1 - arg*std::sin(shift)*fact2);
309
310 if (value < 0.0) bessel = -bessel;
311 }
312 return bessel;
313 }
314
315 ////////////////////////////////////////////////////////////////////
316 //
317 // damp factor in diffraction x/sh(x), x was already *pi
318
319 inline G4double G4DiffuseElasticV2::DampFactor(G4double x)
320 {
321 G4double df;
322 G4double f2 = 2., f3 = 6., f4 = 24.; // first factorials
323
324 // x *= pi;
325
326 if( std::fabs(x) < 0.01 )
327 {
328 df = 1./(1. + x/f2 + x*x/f3 + x*x*x/f4);
329 }
330 else
331 {
332 df = x/std::sinh(x);
333 }
334 return df;
335 }
336
337
338 ////////////////////////////////////////////////////////////////////
339 //
340 // return J1(x)/x with special case for small x
341
342 inline G4double G4DiffuseElasticV2::BesselOneByArg(G4double x)
343 {
344 G4double x2, result;
345
346 if( std::fabs(x) < 0.01 )
347 {
348 x *= 0.5;
349 x2 = x*x;
350 result = 2. - x2 + x2*x2/6.;
351 }
352 else
353 {
354 result = BesselJone(x)/x;
355 }
356 return result;
357 }
358
359
360 ////////////////////////////////////////////////////////////////////
361 //
362 // return Zommerfeld parameter for Coulomb scattering
363
364 inline G4double G4DiffuseElasticV2::CalculateZommerfeld( G4double beta, G4double Z1, G4double Z2 )
365 {
366 fZommerfeld = CLHEP::fine_structure_const*Z1*Z2/beta;
367
368 return fZommerfeld;
369 }
370
371 ////////////////////////////////////////////////////////////////////
372 //
373 // return Wentzel correction for Coulomb scattering
374
375 inline G4double G4DiffuseElasticV2::CalculateAm( G4double momentum, G4double n, G4double Z)
376 {
377 G4double k = momentum/CLHEP::hbarc;
378 G4double ch = 1.13 + 3.76*n*n;
379 G4double zn = 1.77*k*(1.0/G4Pow::GetInstance()->A13(Z))*CLHEP::Bohr_radius;
380 G4double zn2 = zn*zn;
381 fAm = ch/zn2;
382
383 return fAm;
384 }
385
386 ////////////////////////////////////////////////////////////////////
387 //
388 // calculate nuclear radius for different atomic weights using different approximations
389
390 inline G4double G4DiffuseElasticV2::CalculateNuclearRad( G4double A)
391 {
392 G4double R, r0, a11, a12, a13, a2, a3;
393
394 a11 = 1.26; // 1.08, 1.16
395 a12 = 1.; // 1.08, 1.16
396 a13 = 1.12; // 1.08, 1.16
397 a2 = 1.1;
398 a3 = 1.;
399
400 // Special rms radii for light nucleii
401
402 if (A < 50.)
403 {
404 if (std::abs(A-1.) < 0.5) return 0.89*CLHEP::fermi; // p
405 else if(std::abs(A-2.) < 0.5) return 2.13*CLHEP::fermi; // d
406 else if( // std::abs(Z-1.) < 0.5 &&
407 std::abs(A-3.) < 0.5) return 1.80*CLHEP::fermi; // t
408
409 // else if(std::abs(Z-2.) < 0.5 && std::abs(A-3.) < 0.5) return 1.96CLHEP::fermi; // He3
410 else if( // std::abs(Z-2.) < 0.5 &&
411 std::abs(A-4.) < 0.5) return 1.68*CLHEP::fermi; // He4
412
413 else if( // std::abs(Z-3.) < 0.5
414 std::abs(A-7.) < 0.5 ) return 2.40*CLHEP::fermi; // Li7
415 else if( // std::abs(Z-4.) < 0.5
416 std::abs(A-9.) < 0.5) return 2.51*CLHEP::fermi; // Be9
417
418 else if( 10. < A && A <= 16. ) r0 = a11*( 1 - (1.0/G4Pow::GetInstance()->A23(A)) )*CLHEP::fermi; // 1.08CLHEP::fermi;
419 else if( 15. < A && A <= 20. ) r0 = a12*( 1 - (1.0/G4Pow::GetInstance()->A23(A)) )*CLHEP::fermi;
420 else if( 20. < A && A <= 30. ) r0 = a13*( 1 - (1.0/G4Pow::GetInstance()->A23(A)) )*CLHEP::fermi;
421 else r0 = a2*CLHEP::fermi;
422
423 R = r0*G4Pow::GetInstance()->A13(A);
424 }
425 else
426 {
427 r0 = a3*CLHEP::fermi;
428
429 R = r0*G4Pow::GetInstance()->powA(A, 0.27);
430 }
431 fNuclearRadius = R;
432
433 return R;
434 }
435
436
437 #endif
438