diff options
Diffstat (limited to 'Source/Particles')
| -rw-r--r-- | Source/Particles/MultiParticleContainer.H | 22 | ||||
| -rw-r--r-- | Source/Particles/PhotonParticleContainer.H | 7 | ||||
| -rw-r--r-- | Source/Particles/PhysicalParticleContainer.H | 40 | ||||
| -rw-r--r-- | Source/Particles/PhysicalParticleContainer.cpp | 18 | ||||
| -rw-r--r-- | Source/Particles/RigidInjectedParticleContainer.H | 18 | ||||
| -rw-r--r-- | Source/Particles/WarpXParticleContainer.H | 29 |
6 files changed, 119 insertions, 15 deletions
diff --git a/Source/Particles/MultiParticleContainer.H b/Source/Particles/MultiParticleContainer.H index d7ddc7a72..9db129b05 100644 --- a/Source/Particles/MultiParticleContainer.H +++ b/Source/Particles/MultiParticleContainer.H @@ -23,14 +23,20 @@ #include <string> #include <algorithm> -// -// MultiParticleContainer holds multiple (nspecies or npsecies+1 when -// using laser) WarpXParticleContainer. WarpXParticleContainer is -// derived from amrex::ParticleContainer, and it is -// polymorphic. PhysicalParticleContainer and LaserParticleContainer are -// concrete class derived from WarpXParticlContainer. -// - +/** + * The class MultiParticleContainer holds multiple instances of the polymorphic + * class WarpXParticleContainer, stored in its member variable "allcontainers". + * The class WarpX typically has a single (pointer to an) instance of + * MultiParticleContainer. + * + * MultiParticleContainer typically has two types of functions: + * - Functions that loop over all instances of WarpXParticleContainer in + * allcontainers and calls the corresponding function (for instance, + * MultiParticleContainer::Evolve loops over all particles containers and + * calls the corresponding WarpXParticleContainer::Evolve function). + * - Functions that specifically handle multiple species (for instance + * ReadParameters or mapSpeciesProduct). + */ class MultiParticleContainer { diff --git a/Source/Particles/PhotonParticleContainer.H b/Source/Particles/PhotonParticleContainer.H index 580f13f86..9b688cc59 100644 --- a/Source/Particles/PhotonParticleContainer.H +++ b/Source/Particles/PhotonParticleContainer.H @@ -4,6 +4,13 @@ #include <PhysicalParticleContainer.H> #include <AMReX_Vector.H> +/** + * Photon particles have no mass, they deposit no charge, and see specific QED + * effects. For these reasons, they are stored in the separate particle + * container PhotonParticleContainer, that inherts from + * PhysicalParticleContainer. The particle pusher and current deposition, in + * particular, are overriden in this container. + */ class PhotonParticleContainer : public PhysicalParticleContainer { diff --git a/Source/Particles/PhysicalParticleContainer.H b/Source/Particles/PhysicalParticleContainer.H index 1cd4ba621..0192ffb37 100644 --- a/Source/Particles/PhysicalParticleContainer.H +++ b/Source/Particles/PhysicalParticleContainer.H @@ -15,6 +15,13 @@ #include <map> +/** + * PhysicalParticleContainer is the ParticleContainer class containing plasma + * particles (if a simulation has 2 plasma species, say "electrons" and + * "ions"), they will be two instances of PhysicalParticleContainer. + * + * PhysicalParticleContainer inherits from WarpXParticleContainer. + */ class PhysicalParticleContainer : public WarpXParticleContainer { @@ -68,6 +75,39 @@ public: int lev, int depos_lev); + /** + * \brief Evolve is the central function PhysicalParticleContainer that + * advances plasma particles for a time dt (typically one timestep). + * + * \param lev level on which particles are living + * \param Ex MultiFab from which field Ex is gathered + * \param Ey MultiFab from which field Ey is gathered + * \param Ez MultiFab from which field Ez is gathered + * \param Bx MultiFab from which field Bx is gathered + * \param By MultiFab from which field By is gathered + * \param Bz MultiFab from which field Bz is gathered + * \param jx MultiFab to which the particles' current jx is deposited + * \param jy MultiFab to which the particles' current jy is deposited + * \param jz MultiFab to which the particles' current jz is deposited + * \param cjx Same as jx (coarser, from lev-1), when using deposition buffers + * \param cjy Same as jy (coarser, from lev-1), when using deposition buffers + * \param cjz Same as jz (coarser, from lev-1), when using deposition buffers + * \param rho MultiFab to which the particles' charge is deposited + * \param crho Same as rho (coarser, from lev-1), when using deposition buffers + * \param cEx Same as Ex (coarser, from lev-1), when using gather buffers + * \param cEy Same as Ey (coarser, from lev-1), when using gather buffers + * \param cEz Same as Ez (coarser, from lev-1), when using gather buffers + * \param cBx Same as Bx (coarser, from lev-1), when using gather buffers + * \param cBy Same as By (coarser, from lev-1), when using gather buffers + * \param cBz Same as Bz (coarser, from lev-1), when using gather buffers + * \param t current physical time + * \param dt time step by which particles are advanced + * \param a_dt_type type of time step (used for sub-cycling) + * + * Evolve iterates over particle iterator (each box) and performs filtering, + * field gather, particle push and current deposition for all particles + * in the box. + */ virtual void Evolve (int lev, const amrex::MultiFab& Ex, const amrex::MultiFab& Ey, diff --git a/Source/Particles/PhysicalParticleContainer.cpp b/Source/Particles/PhysicalParticleContainer.cpp index d5c08074a..94d9bc363 100644 --- a/Source/Particles/PhysicalParticleContainer.cpp +++ b/Source/Particles/PhysicalParticleContainer.cpp @@ -1431,15 +1431,19 @@ PhysicalParticleContainer::SplitParticles(int lev) { pti.GetPosition(xp, yp, zp); - // offset for split particles is computed as a function of cell size - // and number of particles per cell, so that a uniform distribution - // before splitting results in a uniform distribution after splitting const amrex::Vector<int> ppc_nd = plasma_injector->num_particles_per_cell_each_dim; const std::array<Real,3>& dx = WarpX::CellSize(lev); - amrex::Vector<Real> split_offset = {dx[0]/2._rt/ppc_nd[0], - dx[1]/2._rt/ppc_nd[1], - dx[2]/2._rt/ppc_nd[2]}; - + amrex::Vector<Real> split_offset = {dx[0]/2._rt, + dx[1]/2._rt, + dx[2]/2._rt}; + if (ppc_nd[0] > 0){ + // offset for split particles is computed as a function of cell size + // and number of particles per cell, so that a uniform distribution + // before splitting results in a uniform distribution after splitting + split_offset[0] /= ppc_nd[0]; + split_offset[1] /= ppc_nd[1]; + split_offset[2] /= ppc_nd[2]; + } // particle Array Of Structs data auto& particles = pti.GetArrayOfStructs(); // particle Struct Of Arrays data diff --git a/Source/Particles/RigidInjectedParticleContainer.H b/Source/Particles/RigidInjectedParticleContainer.H index a2473c5ad..fecb9c48e 100644 --- a/Source/Particles/RigidInjectedParticleContainer.H +++ b/Source/Particles/RigidInjectedParticleContainer.H @@ -4,6 +4,24 @@ #include <PhysicalParticleContainer.H> #include <AMReX_Vector.H> +/** + * When injecting a particle beam (typically for a plasma wakefield + * acceleration simulation), say propagating in the z direction, it can + * be necessary to make particles propagate in a straight line up to a given + * location z=z0. This is of particular importance when running in a boosted + * frame, where the beam may evolve due to its space charge fields before + * entering the plasma, causing the actual injected beam, and hence the whole + * simulation result, to depend on the Lorentz factor of the boost. + * + * This feature is implemented in RigidInjectedParticleContainer: At each + * iteration, for each particle, if z<z0 the particle moves in a straight line, + * and if z>z0 the particle evolves as a regular PhysicalParticleContainer. + * + * Note: This option is also useful to build self-consistent space charge + * fields for the particle beam. + * + * RigidInjectedParticleContainer derives from PhysicalParticleContainer. + */ class RigidInjectedParticleContainer : public PhysicalParticleContainer { diff --git a/Source/Particles/WarpXParticleContainer.H b/Source/Particles/WarpXParticleContainer.H index 567bb402d..fa5c586da 100644 --- a/Source/Particles/WarpXParticleContainer.H +++ b/Source/Particles/WarpXParticleContainer.H @@ -101,8 +101,32 @@ public: } }; +// Forward-declaration needed by WarpXParticleContainer below class MultiParticleContainer; +/** + * WarpXParticleContainer is the base polymorphic class from which all concrete + * particle container classes (that store a collection of particles) derive. Derived + * classes can be used for plasma particles, photon particles, or non-physical + * particles (e.g., for the laser antenna). + * It derives from amrex::ParticleContainer<0,0,PIdx::nattribs>, where the + * template arguments stand for the number of int and amrex::Real SoA and AoS + * data in amrex::Particle. + * - AoS amrex::Real: x, y, z (default), 0 additional (first template + * parameter) + * - AoS int: id, cpu (default), 0 additional (second template parameter) + * - SoA amrex::Real: PIdx::nattribs (third template parameter), see PIdx for + * the list. + * + * WarpXParticleContainer contains the main functions for initialization, + * interaction with the grid (field gather and current deposition) and particle + * push. + * + * Note: many functions are pure virtual (meaning they MUST be defined in + * derived classes, e.g., Evolve) or empty function (meaning they + * do not do anything, e.g., FieldGather, meant to be overriden by derived + * function) or actual functions (e.g. CurrentDeposition). + */ class WarpXParticleContainer : public amrex::ParticleContainer<0,0,PIdx::nattribs> { @@ -140,6 +164,11 @@ public: amrex::Real t, amrex::Real dt) = 0; #endif // WARPX_DO_ELECTROSTATIC + /** + * Evolve is the central WarpXParticleContainer function that advances + * particles for a time dt (typically one timestep). It is a pure virtual + * function for flexibility. + */ virtual void Evolve (int lev, const amrex::MultiFab& Ex, const amrex::MultiFab& Ey, const amrex::MultiFab& Ez, const amrex::MultiFab& Bx, const amrex::MultiFab& By, const amrex::MultiFab& Bz, |