[819] | 1 | // |
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| 2 | // ******************************************************************** |
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| 3 | // * License and Disclaimer * |
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| 4 | // * * |
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| 6 | // * the Geant4 Collaboration. It is provided under the terms and * |
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| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
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| 9 | // * include a list of copyright holders. * |
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| 10 | // * * |
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| 11 | // * Neither the authors of this software system, nor their employing * |
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| 12 | // * institutes,nor the agencies providing financial support for this * |
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| 13 | // * work make any representation or warranty, express or implied, * |
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| 14 | // * regarding this software system or assume any liability for its * |
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| 15 | // * use. Please see the license in the file LICENSE and URL above * |
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| 16 | // * for the full disclaimer and the limitation of liability. * |
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| 17 | // * * |
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| 18 | // * This code implementation is the result of the scientific and * |
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| 19 | // * technical work of the GEANT4 collaboration. * |
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| 20 | // * By using, copying, modifying or distributing the software (or * |
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| 21 | // * any work based on the software) you agree to acknowledge its * |
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| 22 | // * use in resulting scientific publications, and indicate your * |
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| 23 | // * acceptance of all terms of the Geant4 Software license. * |
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| 24 | // ******************************************************************** |
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| 25 | // |
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| 26 | // |
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| 27 | // $Id: G4VQCrossSection.hh,v 1.9 2007/11/15 09:36:43 mkossov Exp $ |
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[962] | 28 | // GEANT4 tag $Name: geant4-09-02-ref-02 $ |
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[819] | 29 | // |
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| 30 | // |
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| 31 | // GEANT4 virtual class: G4VQCrossSection -- header file |
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| 32 | // M.V. Kossov, CERN-ITEP(Moscow), 4-FEB-2004 |
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| 33 | // The last update: M.V. Kossov, CERN/ITEP (Moscow) 27-Nov-04 |
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| 34 | // |
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| 35 | // Short description: this G4 virtual class is made for the cross section |
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| 36 | // classes of the CHIPS model, which calculate the cross section for the |
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| 37 | // particular Element (virtual GetCrossSection member function). Each of the |
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| 38 | // CHIPS cross section classes creates its own Dynamic Associative Memory |
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| 39 | // Data Base (DAMDB) for the already used isotopes. For all of them thay use the |
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| 40 | // same algorithm. Common member functions of this algorithm can be in this |
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| 41 | // basic virtual class. Any CHIPS cross section class MUST inherit from this virtual |
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| 42 | // G4VQCrossSection class. In the G4QCollision class the general G4VQCrossSection* |
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| 43 | // pointer is connected to this or that CHIPS cross section class (depending on the |
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| 44 | // projectile particle), so each of the CHIPS cross section class must be |
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| 45 | // an evolving singletone. The singletone nature can not be realized in the |
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| 46 | // virtual class. So each derived CS class must have |
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| 47 | // static G4VQCrossSection* GetPointer(); // Gives a pointer to the singletone |
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| 48 | // static function, which is defined in the *.cc file as |
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| 49 | // // Returns Pointer to the G4VQCrossSection class |
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| 50 | // G4VQCrossSection* G4VQCrossSection::GetPointer() |
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| 51 | // { |
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| 52 | // static G4QXCrossSection theCrossSection; //***Static body of the Cross Section*** |
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| 53 | // return &theCrossSection; |
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| 54 | // } |
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| 55 | // the line |
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| 56 | // //virtual static G4VQCrossSection* GetPointer(); // Gives a pointer to the singletone |
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| 57 | // Reminds about this necesity, but in C++ the virtual static function can not be |
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| 58 | // realised, so the static function can not be realised in the interface. Developers |
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| 59 | // must take care of this themselves because this member fuction is called to get a pointer |
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| 60 | // to the singletone in the G4QCollision class. So there is an agreement to |
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| 61 | // make a separate CS class for each projectile particle, e.g. while the (pi-)d |
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| 62 | // and (pi+)d (as well as [n,z] and [z,n]) cross sections) are almost equal, |
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| 63 | // they must be calculated in different classes: G4QPiMinusCrossSection and |
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| 64 | // G4QPiPlusCrossSections. For the ion-nuclear cross sections there should exist only |
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| 65 | // one G4QIonCrossSection class with a huge (#0f isotopes times #of already produced |
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| 66 | // ions) DAMDB or a general analitic formula with parameters. --- December 2004 --- |
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| 67 | // ----------------------------------------------------------------------- |
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| 68 | // At present (25.11.04) for the test purposes this virtual class is created |
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| 69 | // for ohly G4QPhotonCrossSection, G4QElectronCrossSection, G4QMuonCrossSection, |
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| 70 | // G4QTauCrossSection and G4QProtonCrossSection (only for pp collisions now). |
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| 71 | // **************************************************************************************** |
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| 72 | // ********* This HEADER is temporary moved from the photolepton_hadron directory ********* |
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| 73 | // ******* DO NOT MAKE ANY CHANGE! With time it'll move back to photolepton...(M.K.) ****** |
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| 74 | // **************************************************************************************** |
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| 75 | |
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| 76 | #ifndef G4VQCrossSection_h |
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| 77 | #define G4VQCrossSection_h 1 |
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| 78 | |
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| 79 | #include "G4ParticleTable.hh" |
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| 80 | #include "G4NucleiProperties.hh" |
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| 81 | #include "G4NucleiPropertiesTable.hh" |
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| 82 | #include <vector> |
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| 83 | #include "Randomize.hh" |
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| 84 | |
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| 85 | class G4VQCrossSection |
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| 86 | { |
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| 87 | protected: |
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| 88 | |
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| 89 | G4VQCrossSection() {;} // for each particle a separate instance of G4QCollision should be |
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| 90 | // used (and inside use a separate instance of G4Q*CrossSection) |
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| 91 | |
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| 92 | public: |
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| 93 | virtual ~G4VQCrossSection() {;}// for each particle separate instance of G4QXCrossSection |
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| 94 | //@@ can be improved in future)// should be used and inside a separate istance of CS's |
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| 95 | // Set the new tolerance (abs(p_old/p_new-1)<tolerance) |
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| 96 | static void setTolerance(G4double tol){tolerance=tol;}// Set NewTolerance for SameCrosSec |
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| 97 | |
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| 98 | // At present momentum (pMom) must be in GeV (@@ Units) |
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| 99 | virtual G4double GetCrossSection(G4bool, G4double, G4int, G4int, G4int pPDG=0) |
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| 100 | {return G4double(pPDG);} |
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| 101 | |
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| 102 | virtual G4double ThresholdEnergy(G4int Z, G4int N, G4int PDG=0); // Gives 0 by default |
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| 103 | |
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| 104 | // Define in the derived class, F=0 - create AMDB, F=-1 - read AMDB, F=1 - update AMDB |
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| 105 | virtual G4double CalculateCrossSection(G4bool CS, G4int F, G4int I, G4int PDG, G4int tgZ, |
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| 106 | G4int tgN, G4double pMom)=0;//*** PURE VIRTUAL *** |
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| 107 | |
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| 108 | virtual G4double GetLastTOTCS(); // LastCalculated total cross-section (total elastic) |
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| 109 | |
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| 110 | virtual G4double GetLastQELCS(); // LastCalculated quasielastic cross-section (quasifree) |
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| 111 | |
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| 112 | virtual G4double GetDirectPart(G4double Q2); // DirectInteraction with QuarkPartons (nuA) |
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| 113 | |
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| 114 | virtual G4double GetNPartons(G4double Q2); // #ofQuarkPartons in nonPerturbatPhaseSp(nuA) |
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| 115 | |
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| 116 | // Subroutines for the t-chanel processes with a leader (DIS, Elastic, Quasielastic etc.) |
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| 117 | |
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| 118 | virtual G4double GetExchangeEnergy(); // Returns energy of the t-chanel particle (gam,pi) |
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| 119 | |
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| 120 | virtual G4double GetExchangeT(G4int tZ, G4int tN, G4int pPDG); // -t=Q2 for hadronic |
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| 121 | |
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| 122 | virtual G4double GetSlope(G4int tZ, G4int tN, G4int pPDG); // B-slope of the maim maximum |
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| 123 | |
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| 124 | virtual G4double GetHMaxT(); // max(-t=Q2)/2 for hadronic (MeV^2) |
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| 125 | |
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| 126 | virtual G4double GetExchangeQ2(G4double nu=0); // Q2 for lepto-nuclear reactions |
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| 127 | |
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| 128 | virtual G4double GetVirtualFactor(G4double nu, G4double Q2); // ReductionFactor (leptA) |
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| 129 | |
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| 130 | virtual G4double GetQEL_ExchangeQ2(); // Get randomized Q2 for quasi-elastic scattering |
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| 131 | |
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| 132 | virtual G4double GetNQE_ExchangeQ2(); // Get randomized Q2 for non quasi-elastic scat. |
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| 133 | |
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| 134 | virtual G4int GetExchangePDGCode(); // PDGCode of the Exchange Particle (Pi0 by default) |
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| 135 | |
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| 136 | // Body: Basic Parameters of DAMDB (each derived class can add it's own values) |
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| 137 | // ----------------------------------------------------------------------------- |
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| 138 | // The basic scheme of the DAMDB coveres the cross section for isotopes with fixed |
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| 139 | // Z (lastZ - number of protons) and N (lastN - number of neutrons) from the |
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| 140 | // Threshold momentum (TH) up to infinity. The cross section is first (Tab.1) |
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| 141 | // tabulated from the threshold till the boundary momentum (BP). The Tab.1 is |
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| 142 | // the function of the momentum (p) with the N1 elements. The N1 elements can be |
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| 143 | // not all different from zero. The first non-zero element is F1, the last non-zero |
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| 144 | // element is L1. If TH#0 the Tab.1 can be skipped. It is defined by N1=F1=L1=0 and |
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| 145 | // BP=TH. The Tab.1 is the function of the ln(p) with N2 elements (F2 is the first |
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| 146 | // non-zero element, L2 is the last non-zero element) from BP up tp MP. Both Tab.1 |
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| 147 | // and Tab.2 are calculated when the projectile of the class meet the corresponding |
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| 148 | // ion. After that the tables are stored in the DAMDB for the fast calculations. To |
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| 149 | // avoid a complete calculation of the tables in the low energy calculation case, |
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| 150 | // the lastP momentum is used. The tables are calculated only till the momentum, |
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| 151 | // which already appeared in the simulation for this projectile and this isotope. |
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| 152 | // If the momentum above MP appeared, then the extrapolation function is calculated. |
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| 153 | // So, if lastP>MP it means that the cross section is defined for all energies above |
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| 154 | // TH. All parameters and pointers to arrays MUST be stored (F=0), updated (F=1) and |
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| 155 | // retrieved (F=-1) by the derived class in the CalculateCrossSection(F,I,N,Z,P) |
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| 156 | // function. The parameters are used for the immediate result: if the cross section is |
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| 157 | // calculated for the same Z, N, and fabs(p-lastP)/lastP<.001 (? - a parameter), the same |
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| 158 | // cross section (lastCS) is returned, if p<lastTH, then the 0 cross section is returned. |
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| 159 | // It helps to avoid double counting. The derived class can have only the approximation |
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| 160 | // functions, but such class is too slow, as it calculates the arythmetic equations each |
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| 161 | // time, when it is necessary to get a new cross section. So it is reasonable to |
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| 162 | // precalculate the tables, store them in memory, remember the pointers to these |
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| 163 | // functions and just interpolate them in the range of the most frequent energies (use |
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| 164 | // a LinearFit inline function of this virtual class for that). Starting some high |
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| 165 | // momentum (PM) the functional calculations are unavoidable, but fortunately they are |
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| 166 | // not frequent. In case of the ion-nuclear cross section the functional approach can |
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| 167 | // be reasonable, because tabulated cross-sections demand too much memory. |
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| 168 | // |
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| 169 | // ----------------------------------------------------------------------------- |
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| 170 | protected: |
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| 171 | G4double LinearFit(G4double X, G4int N, G4double* XN, G4double* YN); |
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| 172 | |
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| 173 | G4double EquLinearFit(G4double X, G4int N, G4double X0, G4double DX, G4double* Y); |
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| 174 | |
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| 175 | static G4double tolerance;// relative tolerance in momentum to get old CroSec |
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| 176 | }; |
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| 177 | |
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| 178 | #endif |
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