Modelling of the homogeneous barrier discharge in helium at atmospheric pressure
Modelling of the homogeneous barrier discharge in helium at atmospheric pressure
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DOI：
10.1088/0022-3727/36/1/306
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发表时间：
2003-01-07
影响因子：
3.4
通讯作者：
Behnke, JF
中科院分区：
文献类型：
--
作者：
Golubovskii, YB;Maiorov, VA;Behnke, JF
采用一维流体模型对氦介质中均匀阻挡放电的时空特性进行了数值计算。通过相应速率常数的变化，研究了基本过程对放电行为的影响。对均匀阻挡放电的两种基本模式，即Townsend模式和glow模式进行了模拟和分析解释。汤森德放电的特点是不存在准中性等离子体；在半周期中可能出现几个电流峰值。电流的振荡是由阳极附近的离子产生和阴极上随后的离子电子发射之间的滞后引起的。辉光放电的特异性是在击穿过程中阴极区域和正柱的发展，以及在随后阶段准中性等离子体的存在。正柱的出现是因为等离子体对外部场的屏蔽不是瞬间的。分析了外加电压的幅值和频率、放电间隙宽度和介质阻挡层厚度等外部参数对放电特性的影响。放电模式主要受间隙宽度和势垒厚度的影响，对外加电压的幅度和频率的影响较小。当屏障较薄且放电间隙足够宽时，产生辉光模式；否则，放电是汤森。
Numerical calculations of spatio-temporal characteristics of the homogeneous barrier discharge in helium are performed by means of a one-dimensional fluid model. The influence of the elementary processes on the discharge behaviour is studied by variation of the corresponding rate constants. The simulation and the analytical interpretation are carried out for two basic modes of the homogeneous barrier discharge, i.e. the Townsend and glow modes. The Townsend discharge is characterized by the absence of quasineutral plasma; several current peaks may occur during the half-cycle. The oscillations of the current are caused by a lag between the ion production nearby the anode and the subsequent ion-electron emission on the cathode. The specificity of the glow discharge is the development of a cathode region and a positive column during the breakdown, as well as the presence of quasineutral plasma in subsequent phases. The positive column occurs because the shielding of the external field by the plasma is not instantaneous. The dependence of the discharge behaviour on the external parameters, such as the amplitude and frequency of the applied voltage, discharge gap width, and thickness of dielectric barriers, is analysed. The mode of the discharge is governed mostly by the gap width and barrier thickness and depends weakly on the amplitude and frequency of the applied voltage. As the barriers are thin and the discharge gap is sufficiently wide, the glow mode occurs; otherwise, the discharge is Townsend.