亚大气压介质阻挡辉光放电的特性研究

Study on the Characteristics of Sub-atmospheric Pressure Dielectric Barrier Glow Discharge

亚大气压强下的均匀辉光放电，有可能成为无汞荧光灯。它在材料表面改性、灭菌等领域也有广阔的应用前景。利用水电极在真空玻璃箱内的亚大气压条件下实现了介质阻挡均匀辉光放电。电流波形与放电均匀性没有必然的关系，周期性出现的单电流脉冲无法作为高频下均匀放电的普适性判据。测量了不同气压下氩放电的发射光谱，发现高气压下由于下能级的吸收增加，氩750～850nm的部分谱线强度反而降低。分析了放电照片的灰度均匀性，认为它可以作为判断均匀放电的定量参数。气压越高，越不容易实现均匀放电。气体的均匀放电的气压上限分别是Ar（760 Torr），Ar-O2（600 Torr），N2（525 Torr），N2-O2（375 Torr），空气（300 Torr）。电负性的O2和H2O会吸附自由电子，将提惯击穿电压，影响放电的均匀性。

Uniform glow discharge at sub-atmospheric pressure might be used potentially useful for surface modification and germicide. A water barrier discharge as mercury-free fluorescent lamps. It is also electrode was used to realize glow dielectric at sub-atmospheric pressure in a vacuum glass cavity. It was found that there is no necessary relationship between current waveform and discharge uniformity. The single current pulse in a half period can ＇ t be treated as criterion of uniform discharge in high frequency operation. The emission spectrum of argon discharge at different pressure was measured. The results show the intensity of spectrum lines within 750-850 nm decreases tion of low-lying energy levels increases at higher can be used as a quantitative parameter for judgment of discharge pressure. The grey scale of discharge picture uniformity. It＇s more difficult to obtain a uniform discharge at high pressure. The up limits of pressure for uniform discharge are： argon, 760 Torr; mixture of argon and 5% oxygen, 600 Torr; nitrogen, 525 Torr; mixture of nitrogen and 20% oxygen, 375 Torr; air, 300 Torr. The electronegative oxygen and water molecular will absorb free electrons that lead to the increase of breakdowm voltage and un-uniformity .