Particle-in-cell simulations of initial argon dielectric-barrier discharges

We use the commercial particle-in-cell code MAGIC for simulations of dielectric-barrier discharges (DBDs). The simulations are done in pure argon at atmospheric pressure to avoid many of the complications that occur in air. We study DBDs with an embedded surface electrode and also with an exposed surface electrode. The only particle creation-destruction effect that we consider is the ionization of argon by electron impact. The ion drag is based on the process of charge exchange of an ion with its parent gas. The electron drag cross section is based on the binary-encounter-Bethe cross section with a low energy correction. Our simulations last for only about 1 ns due to the large number of electrons produced, which fill our computer memory. We calculate the momentum imparted to the neutral gas during each time step by collisions with the ions and the electrons, and also the total accumulated momentum density imparted to the neutral gas during the entire simulation. This effect has been called the electrohydrodynamic force. The discharge is so fast that the neutral atoms have no time to move and are considered to be at rest.