The effects of the neon gas pressure and preionization on the current sheath dynamics in a low energy (3.3 kJ) Mather type plasma focus (PF) are investigated. The formation and dynamics of the current sheath are monitored by using a Rogowski coil and a high voltage probe. The experiment is performed to explore the evolution of the plasma sheath and to estimate the range of its velocity during the run-down phases. The Rogowski coil and high voltage probe signals reveal an axisymmetric parabolic current sheath, which propagates down the co-axial tube, and a longer confinement time during the collapse phase with a preionization source.