include/DDG4/Geant4IsotropeGenerator.h

0001 //==========================================================================
0002 //  AIDA Detector description implementation
0003 //--------------------------------------------------------------------------
0004 // Copyright (C) Organisation europeenne pour la Recherche nucleaire (CERN)
0005 // All rights reserved.
0006 //
0007 // For the licensing terms see $DD4hepINSTALL/LICENSE.
0008 // For the list of contributors see $DD4hepINSTALL/doc/CREDITS.
0009 //
0010 // Author     : M.Frank
0011 //
0012 //==========================================================================
0013
0014 #ifndef DDG4_GEANT4ISOTROPEGENERATOR_H
0015 #define DDG4_GEANT4ISOTROPEGENERATOR_H
0016
0017 // Framework include files
0018 #include <DDG4/Geant4ParticleGenerator.h>
0019
0020 /// Namespace for the AIDA detector description toolkit
0021 namespace dd4hep {
0022
0023   /// Namespace for the Geant4 based simulation part of the AIDA detector description toolkit
0024   namespace sim {
0025     /// Generate particles isotrop in space around origine (0,0,0)
0026     /**
0027      *  \author  M.Frank
0028      *  \version 1.0
0029      *  \ingroup DD4HEP_SIMULATION
0030      */
0031     class Geant4IsotropeGenerator: public Geant4ParticleGenerator {
0032     protected:
0033       /// Property: Distribution name. Default: "uniform". Allowed: "uniform", "cos(theta)", "ffbar", "eta"
0034       std::string m_distribution;
0035       /// Property: Minimal phi angular value
0036       double      m_phiMin;
0037       /// Property: Maximal phi angular value
0038       double      m_phiMax;
0039       /// Property: Minimal theta angular value
0040       double      m_thetaMin;
0041       /// Property: Maximal theta angular value
0042       double      m_thetaMax;
0043
0044       /// Particle modification. Caller presets defaults to: ( direction = m_direction,  momentum = [m_momentumMin, m_momentumMax])
0045       /** Use this function to implement isotrop guns, multiple guns etc.
0046           User must return a UNIT vector, which gets scaled with momentum.
0047       */
0048       virtual void getParticleDirection(int num, ROOT::Math::XYZVector& direction, double& momentum) const;
0049       /// e+e- --> ffbar particle distribution ~ 1 + cos^2(theta)
0050       void getParticleDirectionFFbar(int num, ROOT::Math::XYZVector& direction, double& momentum) const;
0051       /// e+e- --> ffbar particle distribution ~ 1 + cos^2(theta)
0052       void getParticleDirectionEta(int num, ROOT::Math::XYZVector& direction, double& momentum) const;
0053       /// Particle distribution ~ cos(theta)
0054       void getParticleDirectionCosTheta(int num, ROOT::Math::XYZVector& direction, double& momentum) const;
0055       /// Uniform particle distribution
0056       void getParticleDirectionUniform(int num, ROOT::Math::XYZVector& direction, double& momentum) const;
0057
0058     public:
0059       /// Inhibit default constructor
0060       Geant4IsotropeGenerator() = delete;
0061       /// Inhibit copy constructor
0062       Geant4IsotropeGenerator(const Geant4IsotropeGenerator& copy) = delete;
0063       /// Standard constructor
0064       Geant4IsotropeGenerator(Geant4Context* context, const std::string& name);
0065       /// Default destructor
0066       virtual ~Geant4IsotropeGenerator();
0067     };
0068   }    // End namespace sim
0069 }      // End namespace dd4hep
0070 #endif // DDG4_GEANT4ISOTROPEGENERATOR_H