Abstract:

The dependences of the characteristic of normal glow current-voltage, and the irradiance identity on the helium gas pressure in the glassy tube of the four anodes DC device were measured and analyzed. The results show that glow discharge can be realized in larger range of gas pressure and electric current with the constant-current mode than with the constant-voltage mode. The helium stable discharge can take place in the pressure range from 1Pa to 800Pa, and in the current up to about 500mA. With the change of the bright spots on the surface of electrodes, the discharge voltage at low current region almost increases exponentially with the current in a certain pressure. The growth of the voltage becomes slower with current increase. Due to increase of collision frequency, the voltage increase speed with the current gets slowly for high gas pressure. The analyzed results indicate that it is abnormal glow discharge. From the irradiance picture obtained with CCD, the plasma shrinking towards the cathode with the pressure increase was observed.

Key words: Four anodes device, Glow discharge, Current-voltage characteristic, Irradiance

摘要：

在四阳极直流放电装置上，测量并分析了辉光放电的电流-电压和发光特征随气压的变化关系。结果表明，采用稳流放电模式比稳压放电具有更宽的稳定放电气压和电流范围，能在从1～800Pa的较宽气压范围内实现氦气辉光放电，放电电流可达到500mA左右。随着电极表面亮斑的变化，对于同一气压，在低电流区，放电电压几乎成指数增长；随电流增大，电压的增长速度变缓；对于高的气压，碰撞频率的增大使得电压随电流升高的速率变小。分析表明，放电处于异常辉光区。从放电管的CCD图像可以看出，对于同一放电电流，随气压的升高，等离子体往阴极收缩。

关键词: 四阳极装置, 辉光放电, 电流-电压特性, 发光