中文摘要：

大气压冷等离子体射流的传播机理一直是人们研究的一个热点．本文采用自洽的二维等离子体流体模型，研究了大气压氦气冷等离子体射流在自身环境气体中以及在介质管中的传播问题．得到了电子密度、电离速率、空间电场以及电子温度等参量的时空分布规律，分析了介质管大小以及介质管介电常数对射流放电性质的影响，得到了一种提高电子密度和射流尺寸的新方法．

英文摘要：

The propagation mechanisms of atmospheric pressure cold plasma jets have recently attracted much attention. In this paper, by using a self-consistent two-dimensional plasma fluid model, we have investigated the propagation problems in the cold atmospheric pressure helium plasma jets that are surrounded by helium itself and thin dielectric tube, respectively. The spatio-temporal distributions of electron density, ionization rate, electrical field, and electron temperature were obtained. It is found that both the radius and the permittivity of dielectric tube have an impact on the discharge characteristics. A new method of improving the electron density and plasma jet size was also proposed.