Numerical Simulations Of Super-Short Nanosecond Pulse Gas Discharge At High Pressures

In recent years, the plasma physics scientific community has paid much attention to the development of high pressure, particularly atmospheric pressure, non-equilibrium plasma sources. High-voltage nanosecond pulse discharge mode is one of the most promising ways to generate large-volume non-equilibrium plasmas, and thus has been motivated by numerous potential discharge applications. The better understandings of the spatial-temporal dynamic behaviors of atmospheric pressure nanosecond pulse discharge are very useful to produce, stabilize and control the atmospheric non-equilibrium plasmas. The generation of large-volume low pressure non-equilibrium plasmas is first introduced in this dissertation, and then the generation of large-volume atmospheric pressure non-equilibrium plasmas, as well as their applications, is presented. The theoretical studies and numerical techniques of high pressure gas glow discharge are also given.High-voltage nanosecond pulse gas discharge to obtain the large-volume uniform non-equilibrium plasmas is introduced and simulated with 1d3v PIC-MCC in conjunction to the renormalization and weighting procedure in this dissertation. The numerical results show us the quite similar spatial-temporal behaviors of atmospheric pressure nanosecond pulse gas discharge in noble gases. The plasma density increases dramatically during the pulse discharge due to the avalanche ionization. There exist the effects of local reverse field and double-peak distributions of charged particles' density in high pressure nanosecond pulse discharge. The evolutions of electron, ion and displacement current densities along the discharge gap are all illustrated as well, and we can see that the independence of total current density is function of time, but not of position. The electron and ion energy distribution functions are also observed, from which it is concluded that large-volume non-equilibrium plasma can be achieved with high-voltage nanosecond pulse discharge. In addition, the effects on the discharge evolution have been presented and discussed when the applied pulse voltage amplitude or the distance between the electrodes varies.