// // ******************************************************************** // * License and Disclaimer * // * * // * The Geant4 software is copyright of the Copyright Holders of * // * the Geant4 Collaboration. It is provided under the terms and * // * conditions of the Geant4 Software License, included in the file * // * LICENSE and available at http://cern.ch/geant4/license . These * // * include a list of copyright holders. * // * * // * Neither the authors of this software system, nor their employing * // * institutes,nor the agencies providing financial support for this * // * work make any representation or warranty, express or implied, * // * regarding this software system or assume any liability for its * // * use. Please see the license in the file LICENSE and URL above * // * for the full disclaimer and the limitation of liability. * // * * // * This code implementation is the result of the scientific and * // * technical work of the GEANT4 collaboration. * // * By using, copying, modifying or distributing the software (or * // * any work based on the software) you agree to acknowledge its * // * use in resulting scientific publications, and indicate your * // * acceptance of all terms of the Geant4 Software license. * // ******************************************************************** // // $Id$ // // ---------------- G4QCoherentChargeExchange header ---------------- // by Mikhail Kossov, December 2003. // Header of G4QCoherentChargeExchange class (hA) of the CHIPS Simulation Branch // ------------------------------------------------------------------------------- // This is a unique CHIPS class for the Hadron-Nuclear Elastic Scattering Prosesses // ------------------------------------------------------------------------------- // At present (Jan-06) only proton-to-neutron & neutron-to-proton scattering on nuclei // are implemented. The scattering of mesons and nuclei on nuclei are possible... // The simulation is based on the CHIPS approximation of total elastic and differential // elastic cross sections from E=0 to the highest energyes. // ------------------------------------------------------------------------------- // Short description: This class resolves an ambiguity in the definition of the // "inelastic" cross section. As it was shown in Ph.D.Thesis (M.Kosov,ITEP,1979) // it is more reasonable to subdivide the total cross-section in the coherent & // incoherent parts, but the measuring method for the "inelastic" cross-sections // consideres the lack of the projectile within the narrow forward solid angle // with the consequent extrapolation of these partial cross-sections, corresponding // to the particular solid angle, to the zero solid angle. The low angle region // is shadowed by the elastic (coherent) scattering. BUT the coherent charge // exchange (e.g. conversion p->n) is included by this procedure as a constant term // in the extrapolation, so the "inelastic" cross-section differes from the // incoherent cross-section by the value of the coherent charge exchange cross // section. Fortunately, this cross-sectoion drops ruther fast with energy increasing. // All Geant4 inelastic hadronic models (including CHIPS) simulate the incoherent // reactions. So the incoherent (including quasielastic) cross-section must be used // instead of the inelastic cross-section. For that the "inelastic" cross-section // must be reduced by the value of the coherent charge-exchange cross-section, which // is estimated (it must be tuned!) in this CHIPS class. The angular distribution // is made (at present) identical to the corresponding coherent-elastic scattering // ----------------------------------------------------------------------------------- #ifndef G4QCoherentChargeExchange_hh #define G4QCoherentChargeExchange_hh // GEANT4 Headers #include "globals.hh" #include "G4ios.hh" #include "Randomize.hh" #include "G4VDiscreteProcess.hh" #include "G4Track.hh" #include "G4Step.hh" #include "G4ParticleTypes.hh" #include "G4VParticleChange.hh" #include "G4ParticleDefinition.hh" #include "G4DynamicParticle.hh" #include "G4ThreeVector.hh" #include "G4LorentzVector.hh" // CHIPS Headers #include "G4QuasiFreeRatios.hh" #include "G4QProtonElasticCrossSection.hh" #include "G4QNeutronElasticCrossSection.hh" #include "G4QIsotope.hh" #include "G4QCHIPSWorld.hh" #include "G4QHadron.hh" #include class G4QCoherentChargeExchange : public G4VDiscreteProcess { public: // Constructor G4QCoherentChargeExchange(const G4String& processName ="CHIPS_CoherChargeExScattering"); // Destructor ~G4QCoherentChargeExchange(); G4bool IsApplicable(const G4ParticleDefinition& particle); G4double GetMeanFreePath(const G4Track& aTrack, G4double previousStepSize, G4ForceCondition* condition); // It returns the MeanFreePath of the process for the current track : // (energy, material) // The previousStepSize and G4ForceCondition* are not used. // This function overloads a virtual function of the base class. // It is invoked by the ProcessManager of the Particle. G4VParticleChange* PostStepDoIt(const G4Track& aTrack, const G4Step& aStep); // It computes the final state of the process (at end of step), // returned as a ParticleChange object. // This function overloads a virtual function of the base class. // It is invoked by the ProcessManager of the Particle. G4LorentzVector GetEnegryMomentumConservation(); G4int GetNumberOfNeutronsInTarget(); private: // Hide assignment operator as private G4QCoherentChargeExchange& operator=(const G4QCoherentChargeExchange &right); // Copy constructor G4QCoherentChargeExchange(const G4QCoherentChargeExchange&); // Calculate XS/t: oxs=true - only CS; xst=true - calculate XS, xst=false(oxs=f/t) - t/tm G4double CalculateXSt(G4bool oxs, G4bool xst, G4double p, G4int Z, G4int N, G4int pPDG); // BODY // Static Parameters -------------------------------------------------------------------- static G4int nPartCWorld; // The#of particles for hadronization (limit of A of fragm.) //--------------------------------- End of static parameters --------------------------- // Working parameters G4VQCrossSection* theCS; G4LorentzVector EnMomConservation; // Residual of Energy/Momentum Cons. G4int nOfNeutrons; // #of neutrons in the target nucleus // Modifires for the reaction G4double Time; // Time shift of the capture reaction G4double EnergyDeposition; // Energy deposited in the reaction static std::vector ElementZ; // Z of the element(i) in theLastCalc static std::vector ElProbInMat; // SumProbabilityElements in Material static std::vector *> ElIsoN; // N of isotope(j) of Element(i) static std::vector *> IsoProbInEl;// SumProbabIsotopes in Element i }; #endif