The development of compressed gas insulated switchgear (GIS) and gas insulated transmission line (GITL) have progressed rapidly worldwide because of the excellent insulating and arc quenching properties of Sulphur Hexa Fluoride (SF6) gas. However, free conducting particles lower the corona onset and breakdown voltage of these systems. Under the action of the applied electric field in a coaxial geometry, conducting particles acquire charge and lift off from the outer enclosure when the electrostatic force from the electric field becomes equal or larger than the force due to gravity. Metallic particles move randomly in gas insulated systems under the action of electric field. The particle may remain in mid-gap or stay around the central conductor for several voltage cycles. Particle movement therefore plays a crucial role in determining the voltages withstand capability of GIS/GITL systems.