Particle attributes

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Available Particle Attributes and Flags

The identifiers of all particle attributes and flags can be found in
$PICSRC/src/picongpu/include/simulation_defines/param/speciesAttributes.param.
They are used to define the species in
/simulation_defines/param/speciesDefinition.param by default or overwritten in one of the various examples.

Attribute name	Description
position_pic	relative in-cell position
momentum	momentum at time step t
momentumPrev	momentum at previous time step t-1 (only with the Radiation plugin)
weighting	number of particles inside macro particle
radiationFlag	value decides if particle undergoes radiation algorithm (only with the Radiation plugin)
globalCellIdx_pic	position in units of cells relative to the (moving) window origin

See Create a new attribute for a short guide on implementing your own particle attributes.

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Particle flags are constant attributes that cannot be changed during the simulation runtime. They are pinned inseparably to the species. Some of their values are set in /simulation_defines/param/species.param

Flag name	Description
atomicNumbers	contains number of protons and electrons for nucleus / ion / atom species
effectiveAtomicNumbers	atomic core charge shielded by inner electrons, defined in ionizerConfig.param
boundElectrons	the number of bound electrons in the shells of ion / atom species
shape	the shape of the macro particles (CIC, TSC, PCS)
particlePusher	algorithm that moves the particles under effect of EM-fields
ionizer	ionization model
interpolation	field to particle interpolation model
current	current solver model

There are two other values that can be accessed by particle[<identifier>_]. The first can be identified by multiMask which encodes numerically if the thread "is" a particle or not and if so: if it leaves the supercell in a specific direction. The second is localCellIdx which describes the position of a particle inside a supercell by a linear index.
See the definition and usage in $PICSRC/src/libPMacc/include/particles/Identifier.hpp

Continue with "Plugins".

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From #142

What particle attributes are there and how can they be accessed?

• a picturesque "tree" of all the available namespaces, a short explanation of their substructure and where to find what