ParticleSource

Using macroDensFunc or relMacroDenFunc

When macroDensFunc or relMacroDenFunc is used, please note that density indirectly specifies the total number of attempts to load a particle. If macroDensFunc determines that half of the particle load attempts will be successful (as with y/LY over the domain {0,LY}), density should be double the number density one actually wishes to appear in the simulation. If one uses a more complex function, for example Gaussian, this normalization factor may take a more complex form.

Working in Cylindrical Coordinates

Care must be taken with 2D ZR cylindrical coordinate systems. The loading algorithm will attempt to load particles almost uniformly in both of the dimensions. It does not take into account the larger volume/area represented at large radius compared with lower radius, so if we allow the particles to uniformly fill this space and allow them to be equally weighted, we end up with a high density of macro- and physical particles near the axis.

To learn how to compensate for this, please see: cylindricalparticles.

ParticleSource parameters

recordParticleSumStats (boolean, optional, default = true)

If true, then at each time step, simple statistics will be recorded for all sourced particles (summed over the entire simulation): including the number of macroparticles sourced, their total weight, and the weighted sum of position coordinates as well as the weighted sum of internal variables (the latter can be divided by the total weight to get average positions and velocities of sourced particles). The total energy is currently not recorded (because of the computational time it takes—if desired, one can set recordParticleData to record individual particle data, and then History to sum the particle energies); however, the total (hence average) momentum can be obtained. This data can be accessed via rm-ptclSumData Histories; it is also used by blocks-conductor to record charge emitted from conductors. The record is cleared after each time step.

recordParticleData (boolean, optional, default = false)

If true, then at each time step all sourced particles will be recorded; they can be accessed via histories (e.g., speciesAbsPtclData2 or speciesBinning) or, e.g., for secondary emission (secondaryEmitter). The record is cleared after each time step.