Interaction blocks pertain to fully-kinetic (binary) or partially-kinetic (unary) interactions, where macroparticles interact with other macroparticles or fluids.
Unary interactions are defined as any interaction that depends upon the full state (position and velocity) of only one particle in the initial state.
For example, kinetic electron scatter on a fluid, where both the position and velocity of kinetic species matter.
Binary interactions are defined as any interaction that depends upon the full state (position and velocity) of two distinct particles in the initial state.
For example, two kinetic species collide.
OAFunc:Note
The same species block can describe the two species participating in the interaction.
All binary interactions in Vorpal depend on a cross-section. The
cross-section in binary interactions can be either builtIn or
user defined using an OAFunc block. Binary
interactions` work with both basic dynamic species (also referred to simply
as species) and cellspecies and with both constant and variable weight
particles.
Note
Although the binary interactions allow a mix of both constant and variable weight particles participating in the interaction, it is preferable that all species type be either constant weight or variable weight.