Charge and Potential Distributions for Particles Approaching Substrates With Regular Structures

The charge and potential distributions for insulating particles approaching a substrate with regular insulating structures are studied by particle-in-cell numerical simulations. An elongated particle and a substrate with elongated structures are considered for flowing plasmas. The plasma flow leads to enhanced ion density and potential regions in the particle wake. The role of the relative position of the particle and the substrate in their interactions is investigated. It is also demonstrated that the interactions are modified by photoemission due to directed UV light. The simulations are in 2-D, with ions and electrons both treated as individual particles.