利用流体模型在氩气环境下模拟得到了微空心阴极维持辉光放电的电势、电子密度、离子密度和电场等放电参数的时空分布特性.模拟结果表明,微空心阴极维持辉光放电在不同的时刻表现出不同的放电模式.放电的初始阶段为汤生放电模式;第二阶段为汤生放电模式向空心阴极效应放电模式过渡阶段,微空心阴极维持辉光放电得到初步发展;第三阶段为空心阴极效应放电模式,微空心阴极维持辉光放电区逐渐形成;第四阶段为放电的稳态阶段.在稳态放电状态下,空心阴极腔内的电子和离子密度峰值达到1015 cm?3,位于空心阴极腔的中心位置,维持辉光放电区电子密度可以达到1013 cm?3.研究结果同时表明,微空心阴极放电促进了微空心阴极维持辉光放电的形成;同时微空心阴极维持辉光放电也促进了微空心阴极放电的发展.另外,实验研究表明,第二阳极对微空心阴极腔内外的电势、电场和带电粒子密度的分布均有重要影响,并且对维持辉光放电区域的影响更加明显.第二阳极是形成维持辉光放电的必要条件.%Micro hollow cathode sustained discharge (MCSD) is simulated by using a fluid model, and the spatiotemoral characteristics of the electric potential, electron density, ion density and electric field are investigated. Results show that the MCSD acts in different modes at different times. The first stage is the Townsend discharge mode. The second is a transition mode from Townsend discharge mode to a hollow cathode effect mode, and the electron density, ion density and electric field near the cathode rise drastically, in which the MCSD is ignited initially. The third stage is the hollow cathode effect mode, and the MCSD forms generally. The last stage is stable discharge state. At the stable discharge stage, the electron density and the ion density each achieve 1015 cm?3 with a peak density located in the center of hollow cathode chamber. The value of electron density in the MCSD region is on the order of 1013 cm ?3. The results also show that the micro-hollow cathode discharge (MHCD) contributes to the formation of MCSD, and the MCSD also facilitates the development of MHCD. In addition, the voltage on the second anode has important influence on the distributions of electric potential, electron density and electric field both inside the hollow cathode and outside the hollow cathode. Moreover, the influence on the MCSD is more apparent than the influence on the MHCD. With the increase of voltage on the second anode, the cathode sheath close to the first anode becomes more and more apparent. The second anode is necessary for the formation of micro-hollow cathode sustained discharge.
展开▼
