Generation and Diagnosis of DC Discharge Plasma in Slender Quartz Tube

The argon plasma was generated by low voltage DC discharge in a slender quartz tube.The influence of the glow discharge conditions, including the discharge distance, discharge power, Ar-pressure and number of cathodes, on the plasma properties was diagnosed with Langmuir double-probe.The results show that the DC discharge conditions significantly affected the properties of Ar-plasma.To be specific, the plasma density was effectively enhanced by increasing the discharge power and number of cathodes; generated at 100 Pa, the highest electron density was measured to be 1.03×10¹⁷ m^-3.The electron temperature decreased with the increases of the discharge power and Ar-pressure.Since longer discharge distance requires higher breakdown voltage, the multi-sectional discharge technique works well to generate plasma at a lower discharge voltage in a fairly long quartz tube.