场致发射阳极用钨网的寿命特性分析

Lifecharacteristic analysis of anode tungstenmesh in a coldcathode diode

通过扫描电镜分析和实验验证,分析了场致发射阳极用钨网被破坏的成因。对钨网进行淬火处理,使钨网表面形成一定厚度的氧化膜,可显著提高钨网使用寿命。不同的淬火温度,将使钨网表面形成不同厚度的氧化膜。实验结果表明,氧化膜厚度的改变,将明显影响钨网的使用寿命。当脉宽90ns、束流6kA、能量1MeV的电子束透过钨网时,钨网表面的氧化膜厚度选在0.4μm左右为宜。

The damage reason of an anode tungstenmesh is analyzed by scanning electron mirror and experiments. When a tungstenmesh is quenchtreated, an oxidizedlayer forms on its surface and the life of the tungstenmesh increases obviously. Auger effect spectrum of tungstenmesh samples shows that the thickness of the oxidizedlayer changes with quenchtreated temperature. The experimental results show that the thickness of the oxidizedlayer obviously affects the life of tungstenmesh. The optimum thickness of the oxidizedlayer is about 400nm when a 90ns(FWHM), 6kA, 1MeV beam passes through the tungstenmesh.