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