Geant4  10.03.p01
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Pages
G4EMDissociationCrossSection Class Reference

#include <G4EMDissociationCrossSection.hh>

Inheritance diagram for G4EMDissociationCrossSection:
Collaboration diagram for G4EMDissociationCrossSection:

Public Member Functions

 G4EMDissociationCrossSection ()
 
 ~G4EMDissociationCrossSection ()
 
virtual G4bool IsElementApplicable (const G4DynamicParticle *, G4int Z, const G4Material *)
 
virtual G4double GetElementCrossSection (const G4DynamicParticle *, G4int Z, const G4Material *)
 
G4PhysicsFreeVector * GetCrossSectionForProjectile (G4double, G4double, G4double, G4double, G4double, G4double)
 
G4PhysicsFreeVector * GetCrossSectionForTarget (G4double, G4double, G4double, G4double, G4double, G4double)
 
G4double GetWilsonProbabilityForProtonDissociation (G4double, G4double)
 
- Public Member Functions inherited from G4VCrossSectionDataSet
 G4VCrossSectionDataSet (const G4String &nam="")
 
virtual ~G4VCrossSectionDataSet ()
 
virtual G4bool IsIsoApplicable (const G4DynamicParticle *, G4int Z, G4int A, const G4Element *elm=0, const G4Material *mat=0)
 
G4double GetCrossSection (const G4DynamicParticle *, const G4Element *, const G4Material *mat=0)
 
G4double ComputeCrossSection (const G4DynamicParticle *, const G4Element *, const G4Material *mat=0)
 
virtual G4double GetIsoCrossSection (const G4DynamicParticle *, G4int Z, G4int A, const G4Isotope *iso=0, const G4Element *elm=0, const G4Material *mat=0)
 
virtual G4Isotope * SelectIsotope (const G4Element *, G4double kinEnergy)
 
virtual void BuildPhysicsTable (const G4ParticleDefinition &)
 
virtual void DumpPhysicsTable (const G4ParticleDefinition &)
 
virtual void CrossSectionDescription (std::ostream &) const
 
virtual G4int GetVerboseLevel () const
 
virtual void SetVerboseLevel (G4int value)
 
G4double GetMinKinEnergy () const
 
void SetMinKinEnergy (G4double value)
 
G4double GetMaxKinEnergy () const
 
void SetMaxKinEnergy (G4double value)
 
const G4String & GetName () const
 

Additional Inherited Members

- Protected Member Functions inherited from G4VCrossSectionDataSet
void SetName (const G4String &)
 
- Protected Attributes inherited from G4VCrossSectionDataSet
G4int verboseLevel
 

Detailed Description

Definition at line 79 of file G4EMDissociationCrossSection.hh.

Constructor & Destructor Documentation

G4EMDissociationCrossSection::G4EMDissociationCrossSection ( )

Definition at line 79 of file G4EMDissociationCrossSection.cc.

80  : G4VCrossSectionDataSet("Electromagnetic dissociation")
81 {
82  // This function makes use of the class which can sample the virtual photon
83  // spectrum, G4EMDissociationSpectrum.
84 
85  thePhotonSpectrum = new G4EMDissociationSpectrum();
86 
87  // Define other constants.
88 
89  r0 = 1.18 * fermi;
90  J = 36.8 * MeV;
91  Qprime = 17.0 * MeV;
92  epsilon = 0.0768;
93  xd = 0.25;
94 }
G4VCrossSectionDataSet(const G4String &nam="")
static constexpr double MeV
Definition: G4SIunits.hh:214
static constexpr double fermi
Definition: G4SIunits.hh:103
G4EMDissociationCrossSection::~G4EMDissociationCrossSection ( )

Definition at line 98 of file G4EMDissociationCrossSection.cc.

99 {
100  delete thePhotonSpectrum;
101 }

Member Function Documentation

G4PhysicsFreeVector * G4EMDissociationCrossSection::GetCrossSectionForProjectile ( G4double  AP,
G4double  ZP,
G4double  ,
G4double  ZT,
G4double  b,
G4double  bmin 
)

Definition at line 165 of file G4EMDissociationCrossSection.cc.

167 {
168 //
169 //
170 // Use Wilson et al's approach to calculate the cross-sections due to the E1
171 // and E2 moments of the field at the giant dipole and quadrupole resonances
172 // respectively, Note that the algorithm is traditionally applied to the
173 // EMD break-up of the projectile in the field of the target, as is implemented
174 // here.
175 //
176 // Initialise variables and calculate the energies for the GDR and GQR.
177 //
178  G4double AProot3 = G4Pow::GetInstance()->powA(AP,1.0/3.0);
179  G4double u = 3.0 * J / Qprime / AProot3;
180  G4double R0 = r0 * AProot3;
181  G4double E_GDR = hbarc / std::sqrt(0.7*amu_c2*R0*R0/8.0/J*
182  (1.0 + u - (1.0 + epsilon + 3.0*u)/(1.0 + epsilon + u)*epsilon));
183  G4double E_GQR = 63.0 * MeV / AProot3;
184 //
185 //
186 // Determine the virtual photon spectra at these energies.
187 //
188  G4double ZTsq = ZT * ZT;
189  G4double nE1 = ZTsq *
190  thePhotonSpectrum->GetGeneralE1Spectrum(E_GDR, b, bmin);
191  G4double nE2 = ZTsq *
192  thePhotonSpectrum->GetGeneralE2Spectrum(E_GQR, b, bmin);
193 //
194 //
195 // Now calculate the cross-section of the projectile for interaction with the
196 // E1 and E2 fields.
197 //
198  G4double sE1 = 60.0 * millibarn * MeV * (AP-ZP)*ZP/AP;
199  G4double sE2 = 0.22 * microbarn / MeV * ZP * AProot3 * AProot3;
200  if (AP > 100.0) sE2 *= 0.9;
201  else if (AP > 40.0) sE2 *= 0.6;
202  else sE2 *= 0.3;
203 //
204 //
205 // ... and multiply with the intensity of the virtual photon spectra to get
206 // the probability of interaction.
207 //
208  G4PhysicsFreeVector *theCrossSectionVector = new G4PhysicsFreeVector(2);
209  theCrossSectionVector->PutValue(0, E_GDR, sE1*nE1);
210  theCrossSectionVector->PutValue(1, E_GQR, sE2*nE2*E_GQR*E_GQR);
211 
212  return theCrossSectionVector;
213 }
static G4Pow * GetInstance()
Definition: G4Pow.cc:55
G4double powA(G4double A, G4double y) const
Definition: G4Pow.hh:259
static constexpr double hbarc
void PutValue(size_t index, G4double energy, G4double dataValue)
G4double GetGeneralE2Spectrum(G4double, G4double, G4double)
G4double GetGeneralE1Spectrum(G4double, G4double, G4double)
static constexpr double amu_c2
static constexpr double MeV
Definition: G4SIunits.hh:214
double G4double
Definition: G4Types.hh:76
static constexpr double millibarn
Definition: G4SIunits.hh:106
static constexpr double microbarn
Definition: G4SIunits.hh:107

Here is the call graph for this function:

Here is the caller graph for this function:

G4PhysicsFreeVector * G4EMDissociationCrossSection::GetCrossSectionForTarget ( G4double  AP,
G4double  ZP,
G4double  AT,
G4double  ZT,
G4double  b,
G4double  bmin 
)

Definition at line 218 of file G4EMDissociationCrossSection.cc.

220 {
221 //
222 // This is a cheaky little member function to calculate the probability of
223 // EMD for the target in the field of the projectile ... just by reversing the
224 // A and Z's for the participants.
225 //
226  return GetCrossSectionForProjectile (AT, ZT, AP, ZP, b, bmin);
227 }
G4PhysicsFreeVector * GetCrossSectionForProjectile(G4double, G4double, G4double, G4double, G4double, G4double)

Here is the call graph for this function:

G4double G4EMDissociationCrossSection::GetElementCrossSection ( const G4DynamicParticle *  theDynamicParticle,
G4int  Z,
const G4Material *   
)
virtual

Reimplemented from G4VCrossSectionDataSet.

Definition at line 125 of file G4EMDissociationCrossSection.cc.

127 {
128  // VI protection for Hydrogen
129  if(1 >= Z) { return 0.0; }
130 
131  //
132  // Get relevant information about the projectile and target (A, Z) and
133  // velocity of the projectile.
134  //
135  const G4ParticleDefinition *definitionP = theDynamicParticle->GetDefinition();
136  G4double AP = definitionP->GetBaryonNumber();
137  G4double ZP = definitionP->GetPDGCharge();
138  G4double b = theDynamicParticle->Get4Momentum().beta();
139 
141  G4double ZT = (G4double)Z;
142  G4double bmin = thePhotonSpectrum->GetClosestApproach(AP, ZP, AT, ZT, b);
143  //
144  //
145  // Calculate the cross-section for the projectile and then the target. The
146  // information is returned in a G4PhysicsFreeVector, which separates out the
147  // cross-sections for the E1 and E2 moments of the virtual photon field, and
148  // the energies (GDR and GQR).
149  //
150  G4PhysicsFreeVector *theProjectileCrossSections =
151  GetCrossSectionForProjectile (AP, ZP, AT, ZT, b, bmin);
152  G4double crossSection =
153  (*theProjectileCrossSections)[0]+(*theProjectileCrossSections)[1];
154  delete theProjectileCrossSections;
155  G4PhysicsFreeVector *theTargetCrossSections =
156  GetCrossSectionForTarget (AP, ZP, AT, ZT, b, bmin);
157  crossSection +=
158  (*theTargetCrossSections)[0]+(*theTargetCrossSections)[1];
159  delete theTargetCrossSections;
160  return crossSection;
161 }
G4ParticleDefinition * GetDefinition() const
static G4NistManager * Instance()
G4PhysicsFreeVector * GetCrossSectionForProjectile(G4double, G4double, G4double, G4double, G4double, G4double)
G4LorentzVector Get4Momentum() const
G4double GetClosestApproach(const G4double, const G4double, G4double, G4double, G4double)
G4double GetAtomicMassAmu(const G4String &symb) const
double G4double
Definition: G4Types.hh:76
G4double GetPDGCharge() const
G4PhysicsFreeVector * GetCrossSectionForTarget(G4double, G4double, G4double, G4double, G4double, G4double)

Here is the call graph for this function:

G4double G4EMDissociationCrossSection::GetWilsonProbabilityForProtonDissociation ( G4double  A,
G4double  Z 
)

Definition at line 232 of file G4EMDissociationCrossSection.cc.

234 {
235 //
236 // This is a simple algorithm to choose whether a proton or neutron is ejected
237 // from the nucleus in the EMD interaction.
238 //
239  G4double p = 0.0;
240  if (Z < 6.0)
241  p = 0.5;
242  else if (Z < 8.0)
243  p = 0.6;
244  else if (Z < 14.0)
245  p = 0.7;
246  else
247  {
248  G4double p1 = (G4double) Z / (G4double) A;
249  G4double p2 = 1.95*G4Exp(-0.075*Z);
250  if (p1 < p2) p = p1;
251  else p = p2;
252  }
253 
254  return p;
255 }
const char * p
Definition: xmltok.h:285
double A(double temperature)
G4double G4Exp(G4double initial_x)
Exponential Function double precision.
Definition: G4Exp.hh:183
double G4double
Definition: G4Types.hh:76

Here is the call graph for this function:

G4bool G4EMDissociationCrossSection::IsElementApplicable ( const G4DynamicParticle *  part,
G4int  Z,
const G4Material *   
)
virtual

Reimplemented from G4VCrossSectionDataSet.

Definition at line 105 of file G4EMDissociationCrossSection.cc.

107 {
108 //
109 // The condition for the applicability of this class is that the projectile
110 // must be an ion and the target must have more than one nucleon. In reality
111 // the value of A for either the projectile or target could be much higher,
112 // since for cases where both he projectile and target are medium to small
113 // Z, the probability of the EMD process is, I think, VERY small.
114 //
115  if (G4ParticleTable::GetParticleTable()->GetIonTable()->IsIon(part->GetDefinition())) {
116  return true;
117  } else {
118  return false;
119  }
120 }
G4ParticleDefinition * GetDefinition() const
static G4ParticleTable * GetParticleTable()

Here is the call graph for this function:


The documentation for this class was generated from the following files: