On Correction Factor in Scaling Law for Low Pressure DC Gas Breakdown

15th International Congress on Plasma Physics; 13th Latin American Workshop on Plasma Physics

Ronchi, G.^1 ; Machida, M.^1

Instituto de Física Gleb Wataghin, UNICAMP, Campinas, SP, Brazil^1

关键词: Correction factors;    Dc discharges;    Electrode distances;    Electrode radii;    Gas breakdown;    Interelectrode gaps;    Low pressure gas;    Plasma wall interaction;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/511/1/012002/pdf
DOI  :  10.1088/1742-6596/511/1/012002

来源: IOP

【 摘 要 】

The low pressure gas breakdown described by Paschen's law in Townsend theory, i.e. the breakdown voltage as a function of gas pressure p and the electrode distance d, provides an accurate description of breakdown in DC discharges when the ratio between inter-electrode gap distance d and electrode radii R tends to zero. On increasing of the ratio d/R, the Paschen's curves are shifted to the region of higher breakdown voltage and higher pd values. A modified Paschen's law recently proposed is well satisfied in our measurements. However, the value of constant b changes not only due to gas type but also according to electrode gap distance; furthermore, gas breakdown voltages are considerably modified by plasma-wall interactions due to glass tube proximity in the discharge.