The study of the commutation of atmospheric pressure noble gas arcs on cold cathodes made of Al, Cu, Ti, graphite, Au, Pd, and Pt is extended to W cathodes. Rods with a diameter of 2 mm are inserted in a UHV tight stainless steel vessel filled with Ar 5.6 or Kr 4.8. The negatively biased electrodes are brought into interaction with arc plasma by a magnetic blast field. Their end faces are mostly polished with diamond grinding powder; some are electrolytic polished, others additionally covered with a thick oxide layer or pasted with W powder. Moreover, electrodes are investigated being doped with Al, K, and Si or doped with ThO₂. The arc commutation is observed by short time photography, streak camera records, and temporally highly resolved optical spectroscopy for a lower and higher voltage applied between the arc plasma and the commutation electrode (CE). Varying the electrode properties revealed that basically ionized vapour of electrode material and less distinctly lowering of the work function by doping accelerate the arc commutation. It is initiated by plasma ions, which initially generate secondary electrons across the whole end face of the electrode. Since the electron emission varies locally, the multiplication of ions within the plasma layer by emitted electrons varies too. The positive feedback between both provokes a constriction of the commutation current and the power input into an arc spot. The electrode vapour promotes at first the development of an arc spot but finally quenches it by cooling the plasma layer in front of it.

中文翻译：

---

致密惰性气体等离子体与冷阴极相互作用的研究：III-纯和掺杂 W 阴极上的电弧点点火

对由 Al、Cu、Ti、石墨、Au、Pd 和 Pt 制成的冷阴极上的大气压惰性气体电弧换向的研究扩展到 W 阴极。将直径为 2 mm 的棒插入填充有 Ar 5.6 或 Kr 4.8 的 UHV 密封不锈钢容器中。负偏压电极通过磁场爆炸场与电弧等离子体相互作用。它们的端面大多用金刚石磨粉抛光；有些是电解抛光的，有些则额外覆盖了厚厚的氧化层或粘贴了钨粉。此外，研究了掺杂Al、K和Si或掺杂ThO _2的电极. 电弧换向通过短时摄影、条纹相机记录和时间上高分辨率的光学光谱来观察，以在电弧等离子体和换向电极 (CE) 之间施加较低和较高的电压。改变电极特性表明，电极材料的基本电离蒸气和掺杂引起的功函数降低不太明显会加速电弧换向。它由等离子离子引发，这些离子最初在电极的整个端面上产生二次电子。由于电子发射局部变化，等离子体层内的离子与发射电子的倍增也变化。两者之间的正反馈引起了换向电流和输入到电弧点的功率的收缩。