摘要
具有快速启动和高速拍照特性的微焦点X射线管具有广泛的应用需求。一种基于碳纳米管场致发射阴极阵列的微焦点X射线管研制成功。采用由微波等离子体化学气相沉积方法制备出的高度定向的、具有优异场致发射性能的碳纳米管微束阵列作为X射线管的冷阴极,以此设计出由六边型铜网为栅极的多级式高分辨率电子光学系统,使该X射线管可以实现高速脉冲拍照特性。当栅极电压为2.7kV时,总发射电流达到2mA,碳纳米管相应的发射电流密度达到2.5A/cm2,此时X射线的焦斑尺寸为39μm,从而可以实现高分辨率X射线成像。
Microfocus X-ray tubes with instant turn-on and high-speed camera characteristics have wide application demands.A vacuum-sealed microfocus X-ray tube was developed,in which vertically aligned carbon nanotube emitters grown by microwave plasma chemical vapor deposition was employed as cold cathode.The cold athodewith very good field emission properties and the multistage high resolution electron optical system with hexagon copper gridenablethe CNT-based X-ray tube high speed pulse picture-taking characteristics.A total emission current of 2mA,corresponding an emission current density of 2.5A/cm^2 was achieved at a copper grid voltage of 2.7kV.A very small X-ray focal spot with a sizeless than 39μm was realized,which indicate the potential of high resolution X-ray imageing.
出处
《真空电子技术》
2015年第1期8-11,23,共5页
Vacuum Electronics
