| Abstract: | In this paper, a one-dimension particle-in-cell (PIC) code (EDIPIC) is employed to simulate theparallel-plate ion extraction process under an externally applied electrostatic field, focusing onthe analysis of the influence of the initial electron temperature on the extracted ion fluxes to themetal plates during the ion extraction process. Compared with previously published results, theplasma oscillations on a timescale of the electron plasma period, and the excitation of the ionacoustic rarefaction waves resulting from the plasma oscillations originating from both thenegative and positive electrodes, are studied for the first time. The modeling results show thatboth the negative and positive extractors can collect ions due to the plasma oscillations and thepropagation of the ion acoustic rarefaction waves. With the increase of the initial electrontemperature achieved by keeping other parameters unchanged, on the one hand, both the ionspeed and flux to the negative and positive plates increase, which leads to a significant decreaseof the ion extraction time, while on the other hand, the ion flux to the positive plate after theformation of a Child–Langmuir sheath is much more sensitive to an increase of the initialelectron temperature than that to the negative plate. The PIC simulation results provide a deeperphysical understanding of the influence of the initial electron temperature on the characteristicsof the entire ion extraction process in a decaying plasma. |
