A potential structure is formed by applying external voltage to a non-uniform Ne collision-dominated plasma sustained by the diffusion from two independent glow discharges. The potential is evolved against the diffusion of free electrons, eventually resulting in a double hump in EEDF in the high-potential region. The axial density profile due to the potential structure is predicted using the hydrodynamic equations by assuming kinetic acceleration of electrons by the electric field and their trapping by the high potential.