| Geant4 Cross Reference |
1 //
2 // ********************************************************************
3 // * License and Disclaimer *
4 // * *
5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. *
10 // * *
11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitation of liability. *
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 *
21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Software license. *
24 // ********************************************************************
25 //
26 //
27 // The lust update: M.V. Kossov, CERN/ITEP(Moscow) 17-June-02
28 //
29 //
30 // G4 Physics class: G4ChipsPionPlusInelasticXS for gamma+A cross sections
31 // Created: M.V. Kossov, CERN/ITEP(Moscow), 20-Dec-03
32 // The last update: M.V. Kossov, CERN/ITEP (Moscow) 15-Feb-04
33 //
34 // -------------------------------------------------------------------------------------
35 // Short description: Cross-sections extracted (by W.Pokorski) from the CHIPS package for
36 // pion interactions. Original author: M. Kossov
37 // -------------------------------------------------------------------------------------
38 //
39
40 #include "G4ChipsPionPlusInelasticXS.hh"
41 #include "G4SystemOfUnits.hh"
42 #include "G4DynamicParticle.hh"
43 #include "G4ParticleDefinition.hh"
44 #include "G4PionPlus.hh"
45
46 #include "G4Log.hh"
47 #include "G4Exp.hh"
48 #include "G4Pow.hh"
49
50 // factory
51 #include "G4CrossSectionFactory.hh"
52 //
53 G4_DECLARE_XS_FACTORY(G4ChipsPionPlusInelasticXS);
54
55 G4ChipsPionPlusInelasticXS::G4ChipsPionPlusInelasticXS():G4VCrossSectionDataSet(Default_Name())
56 {
57 // Initialization of the
58 lastLEN=0; // Pointer to lastArray of LowEn CS
59 lastHEN=0; // Pointer to lastArray of HighEn CS
60 lastN=0; // The last N of calculated nucleus
61 lastZ=0; // The last Z of calculated nucleus
62 lastP=0.; // Last used in cross section Momentum
63 lastTH=0.; // Last threshold momentum
64 lastCS=0.; // Last value of the Cross Section
65 lastI=0; // The last position in the DAMDB
66 LEN = new std::vector<G4double*>;
67 HEN = new std::vector<G4double*>;
68 }
69
70
71 G4ChipsPionPlusInelasticXS::~G4ChipsPionPlusInelasticXS()
72 {
73 std::size_t lens=LEN->size();
74 for(std::size_t i=0; i<lens; ++i) delete[] (*LEN)[i];
75 delete LEN;
76 std::size_t hens=HEN->size();
77 for(std::size_t i=0; i<hens; ++i) delete[] (*HEN)[i];
78 delete HEN;
79 }
80
81 void
82 G4ChipsPionPlusInelasticXS::CrossSectionDescription(std::ostream& outFile) const
83 {
84 outFile << "G4ChipsPionPlusInelasticXS provides the inelastic cross\n"
85 << "section for pion+ nucleus scattering as a function of incident\n"
86 << "momentum. The cross section is calculated using M. Kossov's\n"
87 << "CHIPS parameterization of cross section data.\n";
88 }
89
90 G4bool G4ChipsPionPlusInelasticXS::IsIsoApplicable(const G4DynamicParticle*, G4int, G4int,
91 const G4Element*,
92 const G4Material*)
93 {
94 return true;
95 }
96
97 // The main member function giving the collision cross section (P is in IU, CS is in mb)
98 // Make pMom in independent units ! (Now it is MeV)
99 G4double G4ChipsPionPlusInelasticXS::GetIsoCrossSection(const G4DynamicParticle* Pt, G4int tgZ, G4int A,
100 const G4Isotope*,
101 const G4Element*,
102 const G4Material*)
103 {
104 G4double pMom=Pt->GetTotalMomentum();
105 G4int tgN = A - tgZ;
106
107 return GetChipsCrossSection(pMom, tgZ, tgN, 211);
108 }
109
110
111 G4double G4ChipsPionPlusInelasticXS::GetChipsCrossSection(G4double pMom, G4int tgZ, G4int tgN, G4int)
112 {
113
114 G4bool in=false; // By default the isotope must be found in the AMDB
115 if(tgN!=lastN || tgZ!=lastZ) // The nucleus was not the last used isotope
116 {
117 in = false; // By default the isotope haven't be found in AMDB
118 lastP = 0.; // New momentum history (nothing to compare with)
119 lastN = tgN; // The last N of the calculated nucleus
120 lastZ = tgZ; // The last Z of the calculated nucleus
121 lastI = (G4int)colN.size(); // Size of the Associative Memory DB in the heap
122 j = 0; // A#0f records found in DB for this projectile
123 if(lastI) for(G4int i=0; i<lastI; ++i) // AMDB exists, try to find the (Z,N) isotope
124 {
125 if(colN[i]==tgN && colZ[i]==tgZ) // Try the record "i" in the AMDB
126 {
127 lastI=i; // Remember the index for future fast/last use
128 lastTH =colTH[i]; // The last THreshold (A-dependent)
129 if(pMom<=lastTH)
130 {
131 return 0.; // Energy is below the Threshold value
132 }
133 lastP =colP [i]; // Last Momentum (A-dependent)
134 lastCS =colCS[i]; // Last CrossSect (A-dependent)
135 in = true; // This is the case when the isotop is found in DB
136 // Momentum pMom is in IU ! @@ Units
137 lastCS=CalculateCrossSection(-1,j,211,lastZ,lastN,pMom); // read & update
138 if(lastCS<=0. && pMom>lastTH) // Correct the threshold (@@ No intermediate Zeros)
139 {
140 lastCS=0.;
141 lastTH=pMom;
142 }
143 break; // Go out of the LOOP
144 }
145 j++; // Increment a#0f records found in DB
146 }
147 if(!in) // This isotope has not been calculated previously
148 {
149 //!!The slave functions must provide cross-sections in millibarns (mb) !! (not in IU)
150 lastCS=CalculateCrossSection(0,j,211,lastZ,lastN,pMom); //calculate & create
151 //if(lastCS>0.) // It means that the AMBD was initialized
152 //{
153
154 lastTH = 0; //ThresholdEnergy(tgZ, tgN); // The Threshold Energy which is now the last
155 colN.push_back(tgN);
156 colZ.push_back(tgZ);
157 colP.push_back(pMom);
158 colTH.push_back(lastTH);
159 colCS.push_back(lastCS);
160 //} // M.K. Presence of H1 with high threshold breaks the syncronization
161 return lastCS*millibarn;
162 } // End of creation of the new set of parameters
163 else
164 {
165 colP[lastI]=pMom;
166 colCS[lastI]=lastCS;
167 }
168 } // End of parameters udate
169 else if(pMom<=lastTH)
170 {
171 return 0.; // Momentum is below the Threshold Value -> CS=0
172 }
173 else // It is the last used -> use the current tables
174 {
175 lastCS=CalculateCrossSection(1,j,211,lastZ,lastN,pMom); // Only read and UpdateDB
176 lastP=pMom;
177 }
178 return lastCS*millibarn;
179 }
180
181 // The main member function giving the gamma-A cross section (E in GeV, CS in mb)
182 G4double G4ChipsPionPlusInelasticXS::CalculateCrossSection(G4int F, G4int I,
183 G4int, G4int targZ, G4int targN, G4double Momentum)
184 {
185 static const G4double THmin=27.; // default minimum Momentum (MeV/c) Threshold
186 static const G4double THmiG=THmin*.001; // minimum Momentum (GeV/c) Threshold
187 static const G4double dP=10.; // step for the LEN (Low ENergy) table MeV/c
188 static const G4double dPG=dP*.001; // step for the LEN (Low ENergy) table GeV/c
189 static const G4int nL=105; // A#of LEN points in E (step 10 MeV/c)
190 static const G4double Pmin=THmin+(nL-1)*dP; // minP for the HighE part with safety
191 static const G4double Pmax=227000.; // maxP for the HEN (High ENergy) part 227 GeV
192 static const G4int nH=224; // A#of HEN points in lnE
193 static const G4double milP=G4Log(Pmin);// Low logarithm energy for the HEN part
194 static const G4double malP=G4Log(Pmax);// High logarithm energy (each 2.75 percent)
195 static const G4double dlP=(malP-milP)/(nH-1); // Step in log energy in the HEN part
196 static const G4double milPG=G4Log(.001*Pmin);// Low logarithmEnergy for HEN part GeV/c
197
198 if(F<=0) // This isotope was not the last used isotop
199 {
200 if(F<0) // This isotope was found in DAMDB =-----=> RETRIEVE
201 {
202 G4int sync=(G4int)LEN->size();
203 if(sync<=I) G4cerr<<"*!*G4ChipsPiMinusNuclCS::CalcCrosSect:Sync="<<sync<<"<="<<I<<G4endl;
204 lastLEN=(*LEN)[I]; // Pointer to prepared LowEnergy cross sections
205 lastHEN=(*HEN)[I]; // Pointer to prepared High Energy cross sections
206 }
207 else // This isotope wasn't calculated before => CREATE
208 {
209 lastLEN = new G4double[nL]; // Allocate memory for the new LEN cross sections
210 lastHEN = new G4double[nH]; // Allocate memory for the new HEN cross sections
211 // --- Instead of making a separate function ---
212 G4double P=THmiG; // Table threshold in GeV/c
213 for(G4int k=0; k<nL; k++)
214 {
215 lastLEN[k] = CrossSectionLin(targZ, targN, P);
216 P+=dPG;
217 }
218 G4double lP=milPG;
219 for(G4int n=0; n<nH; n++)
220 {
221 lastHEN[n] = CrossSectionLog(targZ, targN, lP);
222 lP+=dlP;
223 }
224 // --- End of possible separate function
225 // *** The synchronization check ***
226 G4int sync=(G4int)LEN->size();
227 if(sync!=I)
228 {
229 G4cerr<<"***G4ChipsPiMinusNuclCS::CalcCrossSect: Sinc="<<sync<<"#"<<I<<", Z=" <<targZ
230 <<", N="<<targN<<", F="<<F<<G4endl;
231 //G4Exception("G4PiMinusNuclearCS::CalculateCS:","39",FatalException,"DBoverflow");
232 }
233 LEN->push_back(lastLEN); // remember the Low Energy Table
234 HEN->push_back(lastHEN); // remember the High Energy Table
235 } // End of creation of the new set of parameters
236 } // End of parameters udate
237 // =-----------------= NOW the Magic Formula =-------------------------=
238 G4double sigma;
239 if (Momentum<lastTH) return 0.; // It must be already checked in the interface class
240 else if (Momentum<Pmin) // High Energy region
241 {
242 sigma=EquLinearFit(Momentum,nL,THmin,dP,lastLEN);
243 }
244 else if (Momentum<Pmax) // High Energy region
245 {
246 G4double lP=G4Log(Momentum);
247 sigma=EquLinearFit(lP,nH,milP,dlP,lastHEN);
248 }
249 else // UHE region (calculation, not frequent)
250 {
251 G4double P=0.001*Momentum; // Approximation formula is for P in GeV/c
252 sigma=CrossSectionFormula(targZ, targN, P, G4Log(P));
253 }
254 if (sigma<0.) return 0.;
255 return sigma;
256 }
257
258 // Electromagnetic momentum-threshold (in MeV/c)
259 G4double G4ChipsPionPlusInelasticXS::ThresholdMomentum(G4int tZ, G4int tN)
260 {
261 static const G4double third=1./3.;
262 static const G4double pM = G4PionPlus::PionPlus()->Definition()->GetPDGMass(); // Projectile mass in MeV
263 static const G4double tpM= pM+pM; // Doubled projectile mass (MeV)
264 G4double tA=tZ+tN;
265 if(tZ<.99 || tN<0.) return 0.;
266 else if(tZ==1 && tN==0) return 300.; // A threshold on the free proton
267 //G4double dE=1.263*tZ/(1.+G4Pow::GetInstance()->powA(tA,third));
268 G4double dE=tZ/(1.+G4Pow::GetInstance()->powA(tA,third)); // Safety for diffused edge of the nucleus (QE)
269 G4double tM=931.5*tA;
270 G4double T=dE+dE*(dE/2+pM)/tM;
271 return std::sqrt(T*(tpM+T));
272 }
273
274 // Calculation formula for piMinus-nuclear inelastic cross-section (mb) (P in GeV/c)
275 G4double G4ChipsPionPlusInelasticXS::CrossSectionLin(G4int tZ, G4int tN, G4double P)
276 {
277 G4double lP=G4Log(P);
278 return CrossSectionFormula(tZ, tN, P, lP);
279 }
280
281 // Calculation formula for piMinus-nuclear inelastic cross-section (mb) log(P in GeV/c)
282 G4double G4ChipsPionPlusInelasticXS::CrossSectionLog(G4int tZ, G4int tN, G4double lP)
283 {
284 G4double P=G4Exp(lP);
285 return CrossSectionFormula(tZ, tN, P, lP);
286 }
287 // Calculation formula for piMinus-nuclear inelastic cross-section (mb) log(P in GeV/c)
288 G4double G4ChipsPionPlusInelasticXS::CrossSectionFormula(G4int tZ, G4int tN,
289 G4double P, G4double lP)
290 {
291 G4double sigma=0.;
292 if(tZ==1 && !tN) // PiPlus-Proton interaction from G4QuasiElRatios
293 {
294 G4double ld=lP-3.5;
295 G4double ld2=ld*ld;
296 G4double p2=P*P;
297 G4double p4=p2*p2;
298 G4double sp=std::sqrt(P);
299 G4double lm=lP-.32;
300 G4double md=lm*lm+.04;
301 G4double El=(.0557*ld2+2.4+6./sp)/(1.+3./p4);
302 G4double To=(.3*ld2+22.3+5./sp)/(1.+1./p4);
303 sigma=(To-El)+.1/md;
304 }
305 else if(tZ==1 && tN==1) // pimp_tot
306 {
307 G4double p2=P*P;
308 G4double d=lP-2.7;
309 G4double f=lP+1.25;
310 G4double gg=lP-.017;
311 sigma=(.55*d*d+38.+23./std::sqrt(P))/(1.+.3/p2/p2)+18./(f*f+.1089)+.02/(gg*gg+.0025);
312 }
313 else if(tZ<97 && tN<152) // General solution
314 {
315 G4double d=lP-4.2;
316 G4double p2=P*P;
317 G4double p4=p2*p2;
318 G4double a=tN+tZ; // A of the target
319 G4double al=G4Log(a);
320 G4double sa=std::sqrt(a);
321 G4double ssa=std::sqrt(sa);
322 G4double a2=a*a;
323 G4double c=41.*G4Exp(al*.68)*(1.+44./a2)/(1.+8./a)/(1.+200./a2/a2);
324 G4double f=290.*ssa/(1.+34./a/ssa);
325 G4double gg=-1.32-al*.043;
326 G4double u=lP-gg;
327 G4double h=al*(.4-.055*al);
328 G4double r=.01+a2*5.E-8;
329 sigma=(c+d*d)/(1.+(.2-.009*sa)/p4)+f/(u*u+h*h)/(1.+r/p2);
330 }
331 else
332 {
333 G4cerr<<"-Warning-G4ChipsPiPlusNuclearCroSect::CSForm:*Bad A* Z="<<tZ<<", N="<<tN<<G4endl;
334 sigma=0.;
335 }
336 if(sigma<0.) return 0.;
337 return sigma;
338 }
339
340 G4double G4ChipsPionPlusInelasticXS::EquLinearFit(G4double X, G4int N, G4double X0, G4double DX, G4double* Y)
341 {
342 if(DX<=0. || N<2)
343 {
344 G4cerr<<"***G4ChipsPionPlusInelasticXS::EquLinearFit: DX="<<DX<<", N="<<N<<G4endl;
345 return Y[0];
346 }
347
348 G4int N2=N-2;
349 G4double d=(X-X0)/DX;
350 G4int jj=static_cast<int>(d);
351 if (jj<0) jj=0;
352 else if(jj>N2) jj=N2;
353 d-=jj; // excess
354 G4double yi=Y[jj];
355 G4double sigma=yi+(Y[jj+1]-yi)*d;
356
357 return sigma;
358 }
359