真空短间隙微弧级联效应观测

利用0.5 mm间隙微通道板成像器观测了微弧放电的斑点级联效应.实验发现，微弧阴极斑点的运动轨迹呈多类型的折线轨迹，斑点间隙在200—300 μm，首发射阴极斑点的放电强度比次级斑点高一个量级以上，而且次级斑点之间的放电强度相对稳定，次级斑点在放电阴极表面无融蚀现象.实验表明，次级斑点产生机制与首发射存在较强的依赖关系. 关键词： 阴极斑点 微弧级联 微通道板成像器

Observation of micro-arc cascade in vacuum short gap

The cascade effect of cathode spots from vacuum micro-arcing has been observed by micro-channel plate(MCP)imager in direct current mode.The spots-track on MCP surface can be drawn out as a multiform dog-leg path,and betweencenters of spots is 200-300μm.The first spot is always the lucida,and its intensity is about decuple of its subspots.The intensity between cascade sub-spots is at the same level,and sub-spots are nondestructive for MCP cathode surface.The experiments showed that arcing of sub-spots depends on emission of the first spot.