Coulomb collisions and 𝝐𝟎 scaling in the PIC code LePIC for Ion Source Applications

This study investigates the effects of Coulomb collisions and the scaling of the vacuum permittivity constant (ε₀) in the Particle-In-Cell (PIC) code LePIC, developed for ion source applications. Plasma profiles (electron density, temperature, flux, and electric potential) remained consistent under ε₀ scaling, with deviations observed in the sheath regions. Coulomb collisions were modeled using Nanbu’s method, and simulation results were benchmarked against analytical solutions for temperature relaxation. Agreement between numerical and theoretical predictions confirms the reliability of the approach for simulating collision-dominated plasmas in ion sources.