The striation plasmas are usually generated within a positive column of glow discharge, where rich and complex physical interactions are involved, especially, in the medium or high pressures. Along these lines, our work aims to thoroughly investigate the formation and destruction of helium striation plasmas at kPa level pressures. The characteristics of the helium striation plasmas, and especially the optical emission properties are explored. The emission lines of 706.52 nm and 391.44 nm related to the energetic electrons and the high-energy metastable helium atoms respectively, were focused on in this work. The formation of striation plasmas in a helium glow discharge, is mainly associated with the instability originating from the stepwise ionization of high-energy metastable state atoms, Maxwellization of the electron distribution functions and gas heating. Additionally, the destruction effect of helium striation plasmas is of great significance when a small amount of nitrogen or oxygen is mixed into the discharge plasmas. The reduction of the mean electron energy and the consumption of the high-energy metastable helium atoms are considered as the underlying reasons for the destruction of striation plasmas.

辉光放电等离子体正柱区内的自组织条纹现象是气体放电物理中的基础性问题，涉及到电子动力学、输运过程、放电不稳定性、非线性现象等丰富的物理内容，是基础物理及其应用中备受关注的重要课题。本文报道了一种在千帕量级气压下产生的氩气辉光放电条纹等离子体，重点关注了条纹等离子体的电学、光学及电离波传播特征，从物理上分析了氩气条纹等离子体的产生及消除机制。研究结果表明，在此气压下产生的氩气条纹等离子体，其条纹长度约为1.5 mm，且随气压减小；电离波波速为1.87 m/s，频率为1.25 kHz。发射光谱诊断证实，条纹等离子体的产生与丰富的亚稳态原子密切相关，亚稳态原子导致的分步电离过程会引起电离不稳定性，这种不稳定性以电离波的形式传播，使得等离子体参数发生纵向调幅，从而形成明暗相间的条纹等离子体。加入氮气可有效淬灭亚稳态氩原子，调整电子能量分布函数，这使得等离子体的不稳定性条件被破坏，因而，条纹等离子体消失。本工作可为人们进一步认识和理解高气压下辉光放电条纹等离子体的形成及消除机制提供了新的思路和实验依据。