具有七个焦点的碳纳米管阴极分布式X射线源  

Multi-Beam X-ray Source with Seven Focal Spots Based on Field Emission of Carbon Nanotubes Cathode

作　　者：唐华平 陈志强[2,3] 秦占峰 张庆辉 李猛 Tang Huaping;Chen Zhiqiang;Qin Zhanfeng;Zhang Qinghui;Li Meng(NuRay Technology Company Limited,,Changzhou 213000,China;Tsinghua University,Beijing 100084,China;Key Laboratory of Particle & Radiation Imaging ( Tsinghua University) ,Ministry of Education ,Beijing 100084,China)

机构地区：[1]新鸿电子有限公司,常州213000 [2]清华大学工程物理系,北京100084 [3]粒子技术与辐射成像教育部重点实验室(清华大学),北京100084

出　　处：《真空科学与技术学报》2019年第5期406-413,共8页Chinese Journal of Vacuum Science and Technology

基　　金：国家杰出青年科学基金项目(11525521)

摘　　要：介绍一种具有七个焦点的碳纳米管阴极分布式X射线源,具有多焦点集成和可编程脉冲发射的特点,基于该X射线源的辐射成像系统能够快速实现7个不同视角的静态层析成像。碳纳米管阴极采用电泳沉积法制备,单个阴极产生的最大电流可达14 mA,具有很好的大电流发射稳定性和一致性。设计的阳极电压为70 kV,通过模拟仿真计算对结构进行优化,实现了电子束的有效聚焦,平均焦点尺寸小至0.60 mm*0.95 mm,且展现出较好的一致性。整个腔体采用精密加工封装工艺和超高真空排气工艺,获得并保持稳定的超高真空状态。A novel type of the multi-beam X-ray source, comprising seven discrete cathodes made of carbon nanotubes ( CNTs) array and properly aligned, has been successfully developed, which has the characteristics of multi-beam integration and programmable pulse emission. The nanostructures of the self-assembled CNTs array cath ode were characterized with scanning/transmission electron microscopy. Radiation imaging system, based on the newly-developed X-ray source, can quickly achieve seven different views on stationary tomo-synthesis imaging. The simulated test results show that under the favorable conditions, the maximum current, stably emitted from a single CNTs cathode,was be up to 14mA. The optimized X-ray source structure,designed by numerical simulation,is capa ble of effectively and consistently focusing electron beam to an average size of 0.6 mm×0.95 mm at an anode volt age of 70kV. Moreover, ultra-high vacuum ( UHV ) degassing and high precision packaging ensured the required UHV environment of the multi-beam X-ray source.

关 键 词：碳纳米管 碳纳米管阴极 分布式X射线源 静态层析成像 

分 类 号：TN146[电子电信—物理电子学]