High-Performance Cold Cathode X-ray Tubes Using a Carbon Nanotube Field Electron Emitter
High-Performance Cold Cathode X-ray Tubes Using a Carbon Nanotube Field Electron Emitter
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DOI：
10.1021/acsnano.2c02233
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发表时间：
2022-06-10
期刊：
影响因子：
17.1
通讯作者：
Lee，Cheol Jin
中科院分区：
文献类型：
--
作者：
Han，Jun Soo;Lee，Sang Heon;Lee，Cheol Jin
冷阴极X射线管的制造使用的碳纳米管（CNT）场电子发射器由独立的碳纳米管膜，它是由一个高度堆积的碳纳米管网络。在长10 mm、厚7 μm的碳纳米管薄膜边缘垂直排列着许多尖端尖锐的碳纳米管束。使用CNT场发射体的冷阴极X射线管呈现出极高的管电流密度（152 A/cm 2）（对应于106.4 mA的管电流）、95.2%的电子束透射率和0.5 mm的小焦斑尺寸（FSS）。此外，冷阴极X射线管在100 000次拍摄期间也显示出稳定的寿命。冷阴极X射线管的高发射电流密度主要归因于CNT膜的边缘处的大量电子发射位点。小的FSS是由独立的薄CNT膜和优化的曲线形状椭圆聚焦透镜制成的CNT场电子发射体的整体引起的。基于所获得的结果，冷阴极X射线管可以在未来广泛用于各种X射线应用，例如医疗诊断系统和安全检查系统。
A cold cathode X-ray tube was fabricated using a carbon nanotube (CNT) field electron emitter made by a free-standing CNT film which is composed of a highly packed CNT network. A lot of CNT bundles with a sharp tip are vertically aligned at the edge of the thin CNT film with a length of 10 mm and a thickness of 7 μm. The cold cathode X-ray tube using the CNT field emitter presents an extremely high tube current density of 152 A/cm2(corresponding to tube current of 106.4 mA), the electron beam transmittance of 95.2% and a small focal spot size (FSS) of 0.5 mm. In addition, the cold cathode X-ray tube also shows stable lifetime during 100 000 shots. High emission current density of the cold cathode X-ray tube is mainly attributed to a lot of electron emission sites at an edge of the CNT film. The small FSS is caused by an ensemble of the CNT field electron emitter made by a free-standing thin CNT film and the optimized curve-shape elliptical focusing lens. Based on obtained results, the cold cathode X-ray tube can be widely used for various X-ray applications such as medical diagnosis systems and security check systems in the future.