Geant4  10.01.p02
G4GEMProbability.cc
Go to the documentation of this file.
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 // $Id: G4GEMProbability.cc 88987 2015-03-17 10:39:50Z gcosmo $
27 //
28 //---------------------------------------------------------------------
29 //
30 // Geant4 class G4GEMProbability
31 //
32 //
33 // Hadronic Process: Nuclear De-excitations
34 // by V. Lara (Sept 2001)
35 //
36 //
37 // Hadronic Process: Nuclear De-excitations
38 // by V. Lara (Sept 2001)
39 //
40 // J. M. Quesada : several fixes in total GEM width
41 // J. M. Quesada 14/07/2009 bug fixed in total emission width (hbarc)
42 // J. M. Quesada (September 2009) several fixes:
43 // -level density parameter of residual calculated at its right excitation energy.
44 // -InitialLeveldensity calculated according to the right conditions of the
45 // initial excited nucleus.
46 // J. M. Quesada 19/04/2010 fix in emission probability calculation.
47 // V.Ivanchenko 20/04/2010 added usage of G4Pow and use more safe computation
48 // V.Ivanchenko 18/05/2010 trying to speedup the most slow method
49 // by usage of G4Pow, integer Z and A; moved constructor,
50 // destructor and virtual functions to source
51 
52 #include "G4GEMProbability.hh"
53 #include "G4PairingCorrection.hh"
54 #include "G4NucleiProperties.hh"
55 #include "G4PhysicalConstants.hh"
56 #include "G4SystemOfUnits.hh"
57 #include "G4Log.hh"
58 #include "G4Exp.hh"
59 
61  theA(anA), theZ(aZ), Spin(aSpin), theCoulombBarrierPtr(0)
62  // Normalization(1.0)
63 {
66  fPlanck= CLHEP::hbar_Planck*fG4pow->logZ(2);
68 }
69 
71 {
72  delete theEvapLDPptr;
73 }
74 
76  G4double MaximalKineticEnergy)
77 {
78  G4double probability = 0.0;
79 
80  if (MaximalKineticEnergy > 0.0 && fragment.GetExcitationEnergy() > 0.0) {
81  G4double CoulombBarrier = GetCoulombBarrier(fragment);
82 
83  probability =
84  CalcProbability(fragment,MaximalKineticEnergy,CoulombBarrier);
85 
86  // Next there is a loop over excited states for this channel
87  // summing probabilities
88  size_t nn = ExcitEnergies.size();
89  if (0 < nn) {
90  G4double SavedSpin = Spin;
91  for (size_t i = 0; i <nn; ++i) {
92  Spin = ExcitSpins[i];
93  // substract excitation energies
94  G4double Tmax = MaximalKineticEnergy - ExcitEnergies[i];
95  if (Tmax > 0.0) {
96  G4double width = CalcProbability(fragment,Tmax,CoulombBarrier);
97  //JMQ April 2010 added condition to prevent reported crash
98  // update probability
99  if (width > 0. && fPlanck < width*ExcitLifetimes[i]) {
100  probability += width;
101  }
102  }
103  }
104  // Restore Spin
105  Spin = SavedSpin;
106  }
107  }
108  // Normalization = probability;
109  return probability;
110 }
111 
113  G4double MaximalKineticEnergy,
114  G4double V)
115 
116 // Calculate integrated probability (width) for evaporation channel
117 {
118  G4int A = fragment.GetA_asInt();
119  G4int Z = fragment.GetZ_asInt();
120 
121  G4int ResidualA = A - theA;
122  G4int ResidualZ = Z - theZ;
123  G4double U = fragment.GetExcitationEnergy();
124 
125  G4double NuclearMass = fragment.ComputeGroundStateMass(theZ, theA);
126 
127  G4double Alpha = CalcAlphaParam(fragment);
128  G4double Beta = CalcBetaParam(fragment);
129 
130  // ***RESIDUAL***
131  //JMQ (September 2009) the following quantities refer to the RESIDUAL:
132 
133  G4double delta0 = fPairCorr->GetPairingCorrection(ResidualA, ResidualZ);
134 
136  LevelDensityParameter(ResidualA,ResidualZ,MaximalKineticEnergy+V-delta0);
137  G4double Ux = (2.5 + 150.0/G4double(ResidualA))*MeV;
138  G4double Ex = Ux + delta0;
139  G4double T = 1.0/(std::sqrt(a/Ux) - 1.5/Ux);
140  //JMQ fixed bug in units
141  G4double E0 = Ex - T*(G4Log(T/MeV) - G4Log(a*MeV)/4.0
142  - 1.25*G4Log(Ux/MeV) + 2.0*std::sqrt(a*Ux));
143  // ***end RESIDUAL ***
144  // ***PARENT***
145  //JMQ (September 2009) the following quantities refer to the PARENT:
146 
147  G4double deltaCN = fPairCorr->GetPairingCorrection(A, Z);
148  G4double aCN = theEvapLDPptr->LevelDensityParameter(A, Z, U-deltaCN);
149  G4double UxCN = (2.5 + 150.0/G4double(A))*MeV;
150  G4double ExCN = UxCN + deltaCN;
151  G4double TCN = 1.0/(std::sqrt(aCN/UxCN) - 1.5/UxCN);
152  // ***end PARENT***
153 
154  G4double Width;
155  G4double InitialLevelDensity;
156  G4double t = MaximalKineticEnergy/T;
157  if ( MaximalKineticEnergy < Ex ) {
158  //JMQ 190709 bug in I1 fixed (T was missing)
159  Width = (I1(t,t)*T + (Beta+V)*I0(t))/G4Exp(E0/T);
160  //JMQ 160909 fix: InitialLevelDensity has been taken away
161  //(different conditions for initial CN..)
162  } else {
163 
164  //VI minor speedup
165  G4double expE0T = G4Exp(E0/T);
166  static const G4double sqrt2 = std::sqrt(2.0);
167 
168  G4double tx = Ex/T;
169  G4double s0 = 2.0*std::sqrt(a*(MaximalKineticEnergy-delta0));
170  G4double sx = 2.0*std::sqrt(a*(Ex-delta0));
171  // VI: protection against FPE exception
172  if(s0 > 350.) { s0 = 350.; }
173  Width = I1(t,tx)*T/expE0T + I3(s0,sx)*G4Exp(s0)/(sqrt2*a);
174 
175  // VI this cannot happen!
176  // For charged particles (Beta+V) = 0 beacuse Beta = -V
177  //if (theZ == 0) {
178  // Width += (Beta+V)*(I0(tx)/expE0T + 2.0*sqrt2*I2(s0,sx)*G4Exp(s0));
179  //}
180  }
181 
182  //JMQ 14/07/2009 BIG BUG : NuclearMass is in MeV => hbarc instead of hbar_planck must be used
183  // G4double g = (2.0*Spin+1.0)*NuclearMass/(pi2* hbar_Planck*hbar_Planck);
184  G4double gg = (2.0*Spin+1.0)*NuclearMass/(pi2* hbarc*hbarc);
185 
186  //JMQ 190709 fix on Rb and geometrical cross sections according to Furihata's paper
187  // (JAERI-Data/Code 2001-105, p6)
188  // G4double RN = 0.0;
189  G4double Rb = 0.0;
190  if (theA > 4)
191  {
192  G4double Ad = fG4pow->Z13(ResidualA);
193  G4double Aj = fG4pow->Z13(theA);
194  Rb = 1.12*(Aj + Ad) - 0.86*((Aj+Ad)/(Aj*Ad))+2.85;
195  Rb *= fermi;
196  }
197  else if (theA>1)
198  {
199  G4double Ad = fG4pow->Z13(ResidualA);
200  G4double Aj = fG4pow->Z13(theA);
201  Rb=1.5*(Aj+Ad)*fermi;
202  }
203  else
204  {
205  G4double Ad = fG4pow->Z13(ResidualA);
206  Rb = 1.5*Ad*fermi;
207  }
208  // G4double GeometricalXS = pi*RN*RN*std::pow(ResidualA,2./3.);
209  G4double GeometricalXS = pi*Rb*Rb;
210  //end of JMQ fix on Rb by 190709
211 
212  //JMQ 160909 fix: initial level density must be calculated according to the
213  // conditions at the initial compound nucleus
214  // (it has been removed from previous "if" for the residual)
215 
216  if ( U < ExCN )
217  {
218  //JMQ fixed bug in units
219  //VI moved the computation here
220  G4double E0CN = ExCN - TCN*(G4Log(TCN/MeV) - 0.25*G4Log(aCN*MeV)
221  - 1.25*G4Log(UxCN/MeV)
222  + 2.0*std::sqrt(aCN*UxCN));
223 
224  InitialLevelDensity = (pi/12.0)*G4Exp((U-E0CN)/TCN)/TCN;
225  }
226  else
227  {
228  //VI speedup
229  G4double x = U-deltaCN;
230  G4double x1 = std::sqrt(aCN*x);
231 
232  InitialLevelDensity = (pi/12.0)*G4Exp(2*x1)/(x*std::sqrt(x1));
233  }
234 
235  //JMQ 190709 BUG : pi instead of sqrt(pi) must be here according
236  // to Furihata's report:
237  Width *= pi*gg*GeometricalXS*Alpha/(12.0*InitialLevelDensity);
238 
239  return Width;
240 }
241 
243 {
244  G4double s2 = s0*s0;
245  G4double sx2 = sx*sx;
246  G4double S = 1.0/std::sqrt(s0);
247  G4double S2 = S*S;
248  G4double Sx = 1.0/std::sqrt(sx);
249  G4double Sx2 = Sx*Sx;
250 
251  G4double p1 = S *(2.0 + S2 *( 4.0 + S2 *( 13.5 + S2 *( 60.0 + S2 * 325.125 ))));
252  G4double p2 = Sx*Sx2 *(
253  (s2-sx2) + Sx2 *(
254  (1.5*s2+0.5*sx2) + Sx2 *(
255  (3.75*s2+0.25*sx2) + Sx2 *(
256  (12.875*s2+0.625*sx2) + Sx2 *(
257  (59.0625*s2+0.9375*sx2) + Sx2 *(324.8*s2+3.28*sx2))))));
258 
259  p2 *= G4Exp(sx-s0);
260 
261  return p1-p2;
262 }
263 
265 {
267  G4double efermi = 0.0;
268  if(theA > 1) {
270  + neutron_mass_c2 - mass;
271  }
272  G4int nlev = ExcitEnergies.size();
273  G4cout << "GEM: List of Excited States for Isotope Z= "
274  << theZ << " A= " << theA << " Nlevels= " << nlev
275  << " Efermi(MeV)= " << efermi
276  << G4endl;
277  for(G4int i=0; i< nlev; ++i) {
278  G4cout << "Z= " << theZ << " A= " << theA
279  << " Mass(GeV)= " << mass/GeV
280  << " Eexc(MeV)= " << ExcitEnergies[i]
281  << " Time(ns)= " << ExcitLifetimes[i]/ns
282  << G4endl;
283  }
284  G4cout << G4endl;
285 }
G4double I3(G4double s0, G4double sx)
static G4Pow * GetInstance()
Definition: G4Pow.cc:55
static const double MeV
Definition: G4SIunits.hh:193
static G4double GetNuclearMass(const G4double A, const G4double Z)
G4double I1(G4double t, G4double tx)
G4double EmissionProbability(const G4Fragment &fragment, G4double anEnergy)
const G4double pi
G4double CalcAlphaParam(const G4Fragment &) const
G4PairingCorrection * fPairCorr
G4double GetCoulombBarrier(const G4Fragment &fragment) const
#define width
G4double CalcProbability(const G4Fragment &fragment, G4double MaximalKineticEnergy, G4double V)
void Dump() const
G4double a
Definition: TRTMaterials.hh:39
std::vector< G4double > ExcitLifetimes
int G4int
Definition: G4Types.hh:78
G4double logZ(G4int Z) const
Definition: G4Pow.hh:163
G4GLOB_DLL std::ostream G4cout
G4double Z13(G4int Z) const
Definition: G4Pow.hh:127
std::vector< G4double > ExcitSpins
G4int GetA_asInt() const
Definition: G4Fragment.hh:243
const G4double p2
G4double GetPairingCorrection(G4int A, G4int Z) const
const G4double p1
G4VLevelDensityParameter * theEvapLDPptr
static const double GeV
Definition: G4SIunits.hh:196
virtual ~G4GEMProbability()
G4double CalcBetaParam(const G4Fragment &) const
std::vector< G4double > ExcitEnergies
static const G4double A[nN]
G4double G4Log(G4double x)
Definition: G4Log.hh:230
G4double G4Exp(G4double initial_x)
Exponential Function double precision.
Definition: G4Exp.hh:183
static G4PairingCorrection * GetInstance()
virtual G4double LevelDensityParameter(G4int A, G4int Z, G4double U) const =0
G4int GetZ_asInt() const
Definition: G4Fragment.hh:248
#define G4endl
Definition: G4ios.hh:61
G4double I0(G4double t)
double G4double
Definition: G4Types.hh:76
#define ns
Definition: xmlparse.cc:597
G4double ComputeGroundStateMass(G4int Z, G4int A) const
Definition: G4Fragment.hh:298
static const double fermi
Definition: G4SIunits.hh:93
G4double GetExcitationEnergy() const
Definition: G4Fragment.hh:260