基于密度泛函理论计算的二次电子发射 对放电等离子体特性的影响.

Ion-induced secondary electron emission (SEE) was the fundamental physical process for low temperature plasmas.The dielectric surface charge played an important role in the process of SEE,which affects the dynamics of plasma discharge.Compared to the previous model which simplifies the electronic structure and the parameter of surface charges, a more accurate method based on Auger neutralization and the density functional theory (DFT) model was applied to calculate the secondary electron emission coefficient (SEEC) of MgO with accumulated surface charge in the atmospheric pressure helium dielectric barrier discharge (DBD) with nitrogen impurities.It discussed the influence of SEEC considering dielectric surface charge on the spatiotemporal characteristics of DBD.In order to observe the effect of dielectric surface charge on the secondary electron emission process, it introduced the peak-leveled voltage which carry little dielectric surface charge during the discharge process to compare with the sinusoidal voltage.The simulation results showed that when the SEE process considering the dielectric surface charge, the current waveform done not change obviously under the peak-leveled voltage.However, under the sinusoidal voltage, the phase of the discharge moment was advanced, the current amplitude was significantly reduced and the spatial distribution of electrons was more dispersed.The result further verifies the effectiveness of the DFT model in our work, and lays a theoretical foundation for the further study of the physical process of DBD discharge. [ABSTRACT FROM AUTHOR]