The Development of a Prototype Transmission Positron Microscope

近年来，我们对正电子--电子的反物质--的理解得到了很好的扩展。因此，将其用作微观探测器变得现实。本项目的目的是发展透射式正电子显微镜的基本技术如下：1.设计制造最简单的透射式正电子显微镜；2.从能量、束径、角度偏转等方面产生聚焦良好的正电子束；3.对这种聚焦良好的光束进行加速和扫描。研究结果总结如下：1.透射式正电子显微镜的设计和制造：引进了超高真空系统、正电子计数系统等，使我们能够用最简单的装置制造出一台原型显微镜。2.高亮度正电子枪的设计与制造：通过使用几种类型的静电透镜，产生了高亮度正电子束。发现光束的特点适合于微束入射到显微镜中。3.高质量光束的加速和扫描：利用加速静电透镜、扫描电极、聚光镜、物镜和投影镜等组合，搭建了100键透射式正电子显微镜样机，实现了对该显微镜的详细测试和100键左右正电子与固体相互作用的研究。

In recent years, our understanding of a positron, an antimatter of an electron has been well expanded. As a result, the use of it as a microscopic probe becomes realistic. The aim of the present project is the development of basic techniques for a transmission positron microscope as follows: 1. the design manufacture of a prototype transmission positron microscope with the simplest setup, 2. the production of well focused positron beam with respect to energy, beam diameter, angular diversion, 3. the acceleration and scanning of such a well focused beam.Research results are summarized as follows: 1. the design and manufacture of a prototype transmission positron microscope: The introduction of a ultra high vacuum system, a positron counting system and so on enabled us to construct a prototype microscope with the simplest setup. 2. the design and manufacture of a high brightness positron gun: By the use of several types of electrostatic lenses, a high brightness positron beam was produced. The feature of the beam was found to be suitable for the micro beam incident into the microscope. 3. the acceleration and scanning of such a high quality beam:By the combination of acceleration electrostatic lenses, scanning electrodes, condenser lens, objective lens and projector lens and so on, a prototype 100 key transmission positron microscope was constructed.By the above research results, the testing of the microscope in details and the study of the interaction of positrons of around 100 key with solids were made possible.