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Plasma Sci. Technol. ›› 2018, Vol. 20 ›› Issue (5): 054017.doi: 10.1088/2058-6272/aaa436


Discharge characteristics of a needle-to-plate electrode at a micro-scale gap

Ronggang WANG (王荣刚)1,3,4, Qizheng JI (季启政)2 , Tongkai ZHANG (张桐恺)3, Qing XIA (夏清)3, Yu ZHANG (张宇)3 and Jiting OUYANG (欧阳吉庭)3,4   


    1 School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, People’s Republic of China
     2 Beijing Oriental Institute of Measurement &Test, Beijing 100094, People’s Republic of China
    3 School of Physics, Beijing Institute of Technology, Beijing 100081, People’s Republic of China


  • Received:2017-10-20 Published:2017-12-27
  • Supported by:

    This work was supported by National Natural Science Foundation of China (11475019) and the Electrostatic Research Foundation of Liu Shanghe Academicians and Experts Workstation, Beijing Orient Institute of Measurement and Test (BOIMTLSHJD20161002).


To understand the discharge characteristics under a gap of micrometers, the breakdown voltage and current–voltage curve are measured experimentally in a needle-to-plate electrode at a micro-scale gap of 3–50 μm in air. The effect of the needle radius and the gas pressure on the discharge characteristics are tested. The results show that when the gap is larger than 10 μm, the relation between the breakdown voltage and the gap looks like the Paschen curve; while below 10 μm, the breakdown voltage is nearly constant in the range of the tested gap. However, at the same gap distance, the breakdown voltage is still affected by the pressure and shows a trend similar to Paschen’s law. The current–voltage characteristic in all the gaps is similar and follows the trend of a typical Townsend-to-glow discharge. A simple model is used to explain the non-normality of breakdown in the micro-gaps. The Townsend mechanism is suggested to control the breakdown process in this configuration before the gap reduces much smaller in air.

Key words: needle-to-plate electrode, micro-scale gap, gas breakdown