Influence of different cathode surfaces on the breakdown time delay in neon DC glow discharge

• Published in: Vacuum Vol. 89; pp. 62 - 66
• Main Authors: StamenkoviA, S N, MarkoviA, VLj, GociA, SR, JovanoviA, A P
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2013
• Subjects: Breakdown; Breakdown time delay; Cathodes; Deposition; Direct current; Formative time; Galvanic gold layer; Glow discharges; Gold; Neon; Scanning electron microscopy; Statistical time; Time delay; Vacuum deposited gold layer; Galvanic gold layer; Vacuum deposited gold layer; Formative time; Neon; Statistical time; Breakdown time delay
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2012.09.010

The breakdown time delay td in neon DC glow discharge with a galvanic gold layer on the cathode is studied and compared to the measurements on the gas tube with the vacuum deposited gold layer. The influence of the different cathode surfaces is analysed by measuring the breakdown time delay as a function of the afterglow period td¯(τ) (the memory curve) and by measuring the formative time delay dependence on working voltages tf¯(U). In the case of the galvanic gold layer the surface charges remain on the regions with reduced conductivity (cathode spots) whose presence is confirmed by scanning electron microscopy (SEM) image and energy dispersive X-ray (EDS) spectrum. The trapped charges change the cathode secondary electron yield and affect the processes of initiation and formation of gas discharge. Furthermore, it is found that deposited surface charges introduce a new mechanism of surface initiation that is manifested by double-Gaussian distributions of the formative and statistical time delay. ► Comparison of the galvanic and vacuum gold layer as glow discharge cathode. ► Surface initiation introduces double-Gaussian distributions of tf and ts. ► The determination of diffusion coefficient of N2+ in neon. ► The determination of the voltage dependence tf¯(U) for the galvanic and vacuum gold layer.