Line data    Source code

       1             : #ifndef CRPROPA_PARTICLE_STATE_H
       2             : #define CRPROPA_PARTICLE_STATE_H
       3             : 
       4             : #include "crpropa/Vector3.h"
       5             : 
       6             : namespace crpropa {
       7             : /**
       8             :  * \addtogroup Core
       9             :  * @{
      10             :  */
      11             : 
      12             : /**
      13             :  @class ParticleState
      14             :  @brief State of the particle: ID, energy, position, direction
      15             : 
      16             :  The ParticleState defines the state of an ultra-high energy cosmic ray, which
      17             :  is assumed to be traveling at the exact speed of light.
      18             :  The cosmic ray state is defined by particle ID, energy and position and
      19             :  direction vector.
      20             :  For faster lookup mass and charge of the particle are stored as members.
      21             :  */
      22     7230041 : class ParticleState {
      23             : private:
      24             :         int id; ///< particle ID (Particle Data Group numbering scheme)
      25             :         double energy; ///< total energy
      26             :         Vector3d position; ///< position vector in comoving coordinates
      27             :         Vector3d direction; ///< unit vector of velocity or momentum
      28             :         double pmass; ///< particle rest mass
      29             :         double charge; ///< particle charge
      30             : 
      31             : public:
      32             :         /** Constructor for a particle state.
      33             :          @param id                      id of the particle following the PDG numbering scheme
      34             :          @param energy          energy of the particle [in Joules]
      35             :          @param position        vector containing the coordinates of the particle [in meters]
      36             :          @param direction       vector containing the direction of motion of the particle
      37             :          */
      38             :         ParticleState(int id = 0, double energy = 0,
      39             :                         Vector3d position = Vector3d(0, 0, 0),
      40             :                         Vector3d direction = Vector3d(-1, 0, 0));
      41             : 
      42             :         /** Set particle position.
      43             :          In simulations including cosmological effects, the position is given in comoving coordinates.
      44             :          @param pos             vector containing the coordinates of the particle [in meters]
      45             :         */
      46             :         void setPosition(const Vector3d &pos);
      47             :         /** Get position of particle.
      48             :          @returns Position vector of particle. If cosmological effects are included, the coordinates are comoving.
      49             :          */
      50             :         const Vector3d &getPosition() const;
      51             : 
      52             :         /** Set direction unit vector, non unit-vectors are normalized
      53             :          @param dir     vector containing the direction of motion of the particle
      54             :          */
      55             :         void setDirection(const Vector3d &dir);
      56             :         /** Get direction unit vector
      57             :          @returns Normalized vector containing direction of motion of particle.
      58             :          */
      59             :         const Vector3d &getDirection() const;
      60             : 
      61             :         /** Set energy of particle.
      62             :          @param newEnergy       energy to be assigned to particle [in Joules]
      63             :          */
      64             :         void setEnergy(double newEnergy);
      65             :         /** Get energy of particle.
      66             :          @returns Energy of particle [in Joules]
      67             :          */
      68             :         double getEnergy() const;
      69             :         /** Get rigidity of particle, defined as E/(Z*e).
      70             :          @returns Rigidity of the particle [in Volts]
      71             :          */
      72             :         double getRigidity() const;
      73             : 
      74             :         /** Set particle ID.
      75             :          This follows the PDG numbering scheme:
      76             :           https://pdg.lbl.gov/2019/reviews/rpp2019-rev-monte-carlo-numbering.pdf
      77             :          @param newId           id to be assigned to the particle 
      78             :          */
      79             :         void setId(int newId);
      80             :         /** Get particle ID
      81             :          @returns Particle ID (in PDG format).
      82             :          */
      83             :         int getId() const;
      84             : 
      85             :         std::string getDescription() const;
      86             : 
      87             :         // ======== Helper methods ========
      88             : 
      89             :         /** Get electrical charge of the particle.
      90             :          @returns Charge of the particle [in Coulombs]
      91             :          */
      92             :         double getCharge() const;
      93             :         /** Get mass of the particle.
      94             :          @returns Mass of the particle [kg]
      95             :          */
      96             :         double getMass() const;
      97             : 
      98             :         /** Set Lorentz factor and modify the particle's energy accordingly.
      99             :          @param gamma           Lorentz factor
     100             :          */
     101             :         void setLorentzFactor(double gamma);
     102             :         /** Get Lorentz factor
     103             :          @returns Lorentz factor of particle
     104             :          */
     105             :         double getLorentzFactor() const;
     106             : 
     107             :         /** Get velocity: direction times the speed of light.
     108             :          @returns Velocity of particle [m/s]
     109             :          */
     110             :         Vector3d getVelocity() const;
     111             :         /** Get momentum: direction times energy divided by the speed of light 
     112             :          @returns The momentum [kg m/s]
     113             :         */
     114             :         Vector3d getMomentum() const;
     115             : };
     116             : /** @}*/
     117             : 
     118             : } // namespace crpropa
     119             : 
     120             : #endif // CRPROPA_PARTICLE_STATE_H