【摘要】 相干电子束能提供样品上许多重要的信息,点投影显微镜是研究电子束相干特性的有利工具,而高亮度相干电子束可以大大改善电子光学系统空间分辨和能量分辨,可以应用于电子全息摄影和电子干涉测量等领域。本实验装置包括三种模式:①点投影显微镜模式,可以用来研究相干电子束特性;②场离子显微镜模式,可以研究表面原子结构,提供具有原子分辨的实空间原子排列信息;③场发射显微镜模式,可以研究针形样品的场发射特性。这三种模式在一个超高真空系统中可以实时互换。目前实验装置已经达到3.1×10-8Pa压强,并观测了电子显微镜栅网的放大像。更多还原

【Abstract】 The coherent electron beam,whose characteristics can be studied with Point Projection Microscope,provides important information of the sample under observation.High-brightness coherent electron beam,when employed in the electrical optics systems,greatly improves the spatial and energy resolution of the instrument.It can be applied in the field of electron holography and electron interference measurement as well.The Low-Energy Electron Point Source Microscope described in this article works in three modes: ① Point Projection Microscope mode,in which the characteristics of coherent electron beams can be studied;② Field Ion Microscope mode,in which information of surface atom structure is obtained;③ Field Emission Microscope mode,in which the field emission ability of the tip-shaped samples are investigated.The whole system is equipped in an ultra-high vacuum chamber whose base pressure reaches 3.1×10^-8 Pa.Enlarged projection images of bronze grid are observed with this versatile instrument.更多还原