The secondary emission fluxes are automatically computed by the Plasma interface when surface reactions are added to a model. The mean electron energy of the emitted electrons, εk is typically a function of the ionization energy of the impinging ion and the work function of the surface:

where Δεk is the ionization energy (SI unit: V) and Wf is the work function of the surface (SI unit: V). On dielectric surfaces, charge accumulates due to the difference in fluxes between the electrons and ions:

where Ji is the normal total ion current and Je is the normal total electron current. The surface charge density, ρs is used as a boundary condition in the Electrostatics interface: