// // ******************************************************************** // * 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 Liscense, 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: G4GoudsmitSaundersonTable.hh 103884 2017-05-03 08:04:50Z gcosmo $ // // ----------------------------------------------------------------------------- // // GEANT4 Class header file // // File name: G4GoudsmitSaundersonTable // // Author: Mihaly Novak / (Omrane Kadri) // // Creation date: 20.02.2009 // // Class description: // Class to handle multiple scattering angular distributions precomputed by // using Kawrakow-Bielajew Goudsmit-Saunderson MSC model based on the screened // Rutherford DCS for elastic scattering of electrons/positrons [1,2]. This // class is used by G4GoudsmitSaundersonMscModel to sample the angular // deflection of electrons/positrons after travelling a given path. // // Modifications: // 04.03.2009 V.Ivanchenko cleanup and format according to Geant4 EM style // 18.05.2015 M. Novak This class has been completely replaced (only the original // class name was kept; class description was also inserted): // A new version of Kawrakow-Bielajew Goudsmit-Saunderson MSC model // based on the screened Rutherford DCS for elastic scattering of // electrons/positrons has been introduced[1,2]. The corresponding MSC // angular distributions over a 2D parameter grid have been recomputed // and the CDFs are now stored in a variable transformed (smooth) form // together with the corresponding rational interpolation parameters. // The new version is several times faster, more robust and accurate // compared to the earlier version (G4GoudsmitSaundersonMscModel class // that use these data has been also completely replaced) // 28.04.2017 M. Novak: the GS angular distributions has been recomputed, the // data size has been reduced from 16 MB down to 5 MB by using a new // representation, the class has been modified significantly due to // this new data representation. // // References: // [1] A.F.Bielajew, NIMB, 111 (1996) 195-208 // [2] I.Kawrakow, A.F.Bielajew, NIMB 134(1998) 325-336 // // ----------------------------------------------------------------------------- #ifndef G4GoudsmitSaundersonTable_h #define G4GoudsmitSaundersonTable_h 1 #include #include "G4Types.hh" class G4GoudsmitSaundersonTable { public: G4GoudsmitSaundersonTable(); ~G4GoudsmitSaundersonTable(); void Initialise(); // structure to store one GS transformed angular distribution (for a given s/lambda_el,s/lambda_elG1) struct GSMSCAngularDtr { G4int fNumData; // # of data points G4double fQScale; G4double *fUValues; // array of transformed variables G4double *fParamA; // array of interpolation parameters a G4double *fParamB; // array of interpolation parameters b }; void LoadMSCData(); GSMSCAngularDtr* GetOne(G4int indx) {return fGSMSCAngularDistributions1[indx];} void Sampling(G4double lambdaval, G4double qval, G4double scra, G4double &cost, G4double &sint); G4double SampleCosTheta(G4double lambdaval, G4double qval, G4double scra, G4double rndm1, G4double rndm2, G4double rndm); G4double SampleCosTheta1(G4double lambdaval, G4double qval, G4double scra, G4double rndm1, G4double rndm2, G4double rndm); G4double SampleCosTheta2(G4double lambdaval, G4double qval, G4double scra, G4double rndm1, G4double rndm2, G4double rndm); G4double GetScreeningParam(G4double G1); // material dependent MSC parameters (computed at initialisation) regarding // Moliere's screening parameter G4double GetMoliereBc(G4int matindx){return (*fgMoliereBc)[matindx];} G4double GetMoliereXc2(G4int matindx){return (*fgMoliereXc2)[matindx];} private: // initialisation of material dependent Moliere's MSC parameters void InitMoliereMSCParams(); private: static bool gIsInitialised; // are the precomputed angular distributions already loaded in? static constexpr G4int gLAMBNUM = 64; // # L=s/lambda_el in [fLAMBMIN,fLAMBMAX] static constexpr G4int gQNUM1 = 15; // # Q=s/lambda_el G1 in [fQMIN1,fQMAX1] in the 1-st Q grid static constexpr G4int gQNUM2 = 32; // # Q=s/lambda_el G1 in [fQMIN2,fQMAX2] in the 2-st Q grid static constexpr G4int gNUMSCR1 = 201; // # of screening parameters in the A(G1) function static constexpr G4int gNUMSCR2 = 51; // # of screening parameters in the A(G1) function static constexpr G4double gLAMBMIN = 1.0; // minimum s/lambda_el static constexpr G4double gLAMBMAX = 100000.0; // maximum s/lambda_el static constexpr G4double gQMIN1 = 0.001; // minimum s/lambda_el G1 in the 1-st Q grid static constexpr G4double gQMAX1 = 0.99; // maximum s/lambda_el G1 in the 1-st Q grid static constexpr G4double gQMIN2 = 0.99; // minimum s/lambda_el G1 in the 1-st Q grid static constexpr G4double gQMAX2 = 7.99; // maximum s/lambda_el G1 in the 1-st Q grid // precomputed A(G1) function with its interpolation parameters static constexpr G4double gSCRMIN1 = 1.93214991408357e-12; static constexpr G4double gSCRMAX1 = 2.42974344203683e-01; static constexpr G4double gSCRMAX2 = 5.50564555556202e+01; // static const G4double gG1Values1[]; static const G4double gScrAValues1[]; static const G4double gScrBValues1[]; static const G4double gG1Values2[]; static const G4double gScrAValues2[]; static const G4double gScrBValues2[]; G4double fLogLambda0; // ln(gLAMBMIN) G4double fLogDeltaLambda; // ln(gLAMBMAX/gLAMBMIN)/(gLAMBNUM-1) G4double fInvLogDeltaLambda; // 1/[ln(gLAMBMAX/gLAMBMIN)/(gLAMBNUM-1)] G4double fInvDeltaQ1; // 1/[(gQMAX1-gQMIN1)/(gQNUM1-1)] G4double fDeltaQ2; // [(gQMAX2-gQMIN2)/(gQNUM2-1)] G4double fInvDeltaQ2; // 1/[(gQMAX2-gQMIN2)/(gQNUM2-1)] // for the precumputed A(G1) function G4double fLogG1FuncMin1; G4double fInvLogDeltaG1Func1; G4double fLogG1FuncMin2; G4double fInvLogDeltaG1Func2; // vector to store all GS transformed angular distributions std::vector fGSMSCAngularDistributions1; std::vector fGSMSCAngularDistributions2; //@{ /** Precomputed \f$ b_lambda_{c} $\f and \f$ \chi_c^{2} $\f material dependent * Moliere parameters that can be used to compute the screening parameter, * the elastic scattering cross section (or \f$ \lambda_{e} $\f) under the * screened Rutherford cross section approximation. (These are used in * G4GoudsmitSaundersonMscModel if fgIsUsePWATotalXsecData is FALSE.) */ static std::vector *fgMoliereBc; static std::vector *fgMoliereXc2; }; #endif