深紫外激光光发射与热发射电子显微镜在热扩散阴极研究中的应用  

Applications of deep ultraviolet laser photo- and thermal-emission electron microscope in thermal dispenser cathode research

作　　者：任峰 阴生毅[1] 卢志鹏 李阳[1] 王宇[1] 张申金[3] 杨峰[3] 卫东 Ren Feng Yin Sheng-Yi Lu Zhi-Peng Li Yang Wang Yu Zhang Shen-Jin Yang Feng Wei Dong(Key Laboratory of High Power Microwave Sources and Technology, Institute of Electronics, Chinese Academy of Sciences Beijing 100190, China University of Chinese Academy of Sciences, Beijing 100039, China Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China KYKY Technology co., Ltd, Belling 100190, China)

机构地区：[1]中国科学院电子学研究所,高功率微波源与技术实验室,北京100190 [2]中国科学院大学,北京100039 [3]中国科学院理化技术研究所,功能晶体与激光技术重点实验室,北京100190 [4]北京中科科仪股份有限公司,北京100190

出　　处：《物理学报》2017年第18期225-234,共10页Acta Physica Sinica

基　　金：国家科技重大专项(批准号:2012YQ120048)资助的课题~~

摘　　要：对热扩散阴极表面微区发射状态进行原位观察和分析一直是热阴极研究的重要课题.本文着重介绍深紫外激光光发射电子/热发射电子显微镜的基本原理及其在热扩散阴极研究中的典型实例.系统配备了高温激活所用的加热装置,样品可被加热至1400℃.系统具有光发射电子、阴极热发射电子、光发射电子和阴极热发射电子联合三种电子成像模式.应用表明,对于热扩散阴极而言,深紫外激光光发射电子像适于呈现阴极表面的微观结构形貌;热发射电子像适于反映阴极表面的本征热电子发射及均匀性;光电子和热电子联合成像适于对阴极表面的有效发射点做出精确定位.The research of micro-region emission state for thermal dispenser cathode surface, especially in-situ observation and analysis, is an important subject in the field of thermal cathode. A newly developed instrument aiming at meeting the special operation requirements of thermal dispenser cathode is used to carry out this research. This instrument combines the functions of deep ultraviolet laser photo-emission electron microscope and thermal-emission electron microscope, so it is called DUV-PEEM/TEEM. In this paper, its basic principle is introduced emphatically. In addition, the actual applications of the microscope system to the electron emission investigation of thermal dispenser cathode are displayed.This system is equipped with the heating unit, which is used for activating the thermal dispenser cathode sample, and the temperature of sample can reach 1400℃. The system has three imaging modes, namely, photoemission electron imaging,cathode thermal emission electron imaging, and united imaging by integrating cathode thermal emission electron and photoemission electron. By applying new microscope system to traditional thermal dispenser cathode, we acquire the photoemission electron images of impregnated barium aluminate cathode surface at room temperature. In the heating process, we observe the thermal electron emission phenomenon originating from thermal dispenser cathode and record the variation process with temperature change. A high emission cathode which we developed before, is also studied with DUV-PEEM/TEEM. Fortunately, we find that some bright stripes appear on the surface of high emission cathode when the cathode temperature reaches 800℃. The widths of these bright stripes are about 100 nm. We calculate the thermal emission electron imaging resolution of this system by using these thermal electron emission stripes and the obtained resolution reaches 28 nm. Conveniently, the emission performance and uniformity of this high emission cathode are compared with those of traditional impregnated barium alu

关 键 词：深紫外激光 光发射电子显微镜 热发射电子显微镜 扩散阴极 

分 类 号：O462[理学—电子物理学]