TrackPAI.hh

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#ifndef G_TRACK_PAI
#define G_TRACK_PAI
 
#include <string>
#include <vector>
 
#include "Track.hh"
 
namespace Garfield {
 
/// Energy loss calculation using the Photoabsorption-Ionisation Model.
 
class TrackPAI : public Track {
 
 public:
  // Constructor
  TrackPAI();
  // Destructor
  virtual ~TrackPAI() {}
 
  virtual bool NewTrack(const double x0, const double y0, const double z0,
                        const double t0, const double dx0, const double dy0,
                        const double dz0);
 
  virtual bool GetCluster(double& xcls, double& ycls, double& zcls, 
                          double& tcls, int& ncls, double& ecls, double& extra);
 
  virtual double GetClusterDensity();
  virtual double GetStoppingPower();
 
 private:
  bool m_ready;
 
  // Particle coordinates and direction
  double m_x, m_y, m_z, m_t;
  double m_dx, m_dy, m_dz;
  // Particle energy and speed
  double m_e;
  double m_speed;
  // Max. energy transfer in a collision
  double m_emax;
 
  // Total inelastic mean free path
  double m_imfp;
  // Stopping power
  double m_dedx;
 
  // Dielectric function
  int m_nSteps;
  struct opticalData {
    double eps1, eps2;
    double integral;
  };
  std::vector<opticalData> m_opticalDataTable;
 
  // Tables for interpolation of cumulative distribution functions
  std::vector<double> m_energies;
  std::vector<double> m_cdf;
  std::vector<double> m_rutherford;
 
  struct electron {
    // Direction
    double dx, dy, dz;
    // Energy
    double energy;
    // Type (electron, hole)
    int type;
  };
  std::vector<electron> m_electrons;
  std::vector<electron> m_holes;
 
  // Medium properties
  std::string m_mediumName;
  double m_mediumDensity;
  double m_electronDensity;
 
  bool SetupMedium(Medium* medium);
  bool SetupCrossSectionTable();
 
  double ComputeMaxTransfer() const;
 
  double ComputeCsTail(const double emin, const double emax);
  double ComputeDeDxTail(const double emin, const double emax);
 
  double SampleEnergyDeposit(const double u, double& f) const;
  double SampleAsymptoticCs(double u) const;
  double SampleAsymptoticCsSpinZero(const double emin, double u) const;
  double SampleAsymptoticCsSpinHalf(const double emin, double u) const;
  double SampleAsymptoticCsSpinOne(const double emin, double u) const;
  double SampleAsymptoticCsElectron(const double emin, double u) const;
  double SampleAsymptoticCsPositron(const double emin, double u) const;
 
  double LossFunction(const double eps1, const double eps2) const {
    const double eps = eps1 * eps1 + eps2 * eps2;
    return eps > 0. ? eps2 / eps : 0.;
  }
};
}
 
#endif