collision::binarycollision::virtualphotons Namespace Reference

Typedefs
using	SoaData_type = typename WarpXParticleContainer::ParticleTileType::ParticleTileDataType

Functions
void	GenerateVirtualPhotons (MultiParticleContainer *mypc)

Typedef Documentation

SoaData_type

using collision::binarycollision::virtualphotons::SoaData_type = typename WarpXParticleContainer::ParticleTileType::ParticleTileDataType

Function Documentation

GenerateVirtualPhotons()

void collision::binarycollision::virtualphotons::GenerateVirtualPhotons

(

MultiParticleContainer *

mypc

)

Generate virtual photons from primary particles (electrons or positrons) using the equivalent photon approximation, also known as the Weizsacker-Williams method. The virtual photon species is regenerated from scratch at each time step. This means that any virtual photons that were previously generated by mypc are overwritten.

See for example Jackson, Classical Electrodynamics, 3rd edition, section 15.4 or Berestetskii, Lifshitz, Pitaevskii, Quantum Electrodynamics, 2nd edition, section 99.

The number of photons per primary particle is computed according to Berestetskii's formula 99.16, integrated over angles and over photon energies from a minimum energy (input parameter) up to the energy of the primary particle. The photons are assumed to be emitted in the direction of motion of the primary particle. The virtual photons are generated in a separate species, which can then be used as input for other processes, e.g., Breit-Wheeler pair production and Compton scattering. The virtual photons are generated at the same position as the primary particle, and inherit the same weight as the primary particle, divided by a sampling factor. In the current implementation, the primary particles are not affected by the possible interactions that the virtual photons may undergo.

Parameters

[in]

mypc

MultiParticleContainer calling this method