Development of specular-reflecting wall by super-flattening process and its appliation to vacuum technology

本课题的主要目的是实现热能气体分子的镜面反射壁，其关键技术是实际壁面材料的超平整化和低真空条件下无吸附剂的表面清洗，在本课题中，我们将我们的活动分为三个子主题：（1）在原子尺度上开发平坦表面;（2）通过使用共振增强多波长激光器测量漫散射的偏差;光子电离技术（REMPI）（3）分子束技术直接测量散射分子的角分布。（1）原子尺度下的平坦表面研究我们主要研究了抛光Pt表面的平坦化过程。用扫描隧道显微镜研究了离子轰击解理后粗糙表面的平整化。确定了形成单原子高度阶地的条件。(2)用激光测量漫散射的偏差 ...更多信息 共振多光子电离技术我们将共振多光子电离技术应用于高真空环境中氢分子的探测。利用Nd-YAG激光器倍频，然后在BBO晶体中和频产生紫外光。最低检测限小于1 × 10 ~（13）<-6>Pa。作为镜面反射的证明，我们试图通过铂毛细管测量氢分子的角分布。目前，测量不成功，主要是由于真空系统中缺乏足够的抽气速度。真空泵的改进将被完成。(3)利用分子束技术直接测量散射分子的角分布筑波大学研制了一台分子束装置，并应用于金属表面改性的角分布测量。氦和氩的镜面反射被证明是非常小的漫散射分量。REMPI和分子束散射装置的组合正在开发中。少

The primaryaim of this project is to realize a specular reflecting wall for thermal energy gasmolecules The key technology to the processing of the specular reflecting wall is thought to be super-flattening of practical wall materials and adsorbate-free surface cleaning in ultrahigh vacuum condition.In the proiect, we divided our activity into three sub-themes(1) Development of flat surfaces in atomic scale(2) Measurement of deviations from diffuse scattering by using resonant enhanced multi-photon ionization technique (REMPI)(3) Direct measurement of angular distribution of scattered molecules by molecular beam technique.(1)Development of flat surfaces in atomic scaleWe mainly studied the flattening process of polished Pt surfaces. The flattening of rough surfaces after ion bombardment for the cleaing was studied by scanning tunneling microscope. The condition for the formation of monatomic-height terrace was determined.(2) Measurement of deviations from diffuse scattering by using re … More sonant multi-photon ionization techniqueWe applied resonant multiphoton ionization technique to the detection of hydrogen molecules which are the major constituent in ultrahigh vacuum environment. The ultraviolet light was generated by frequency doubling of Nd-YAG laser followed by sum-frequency generation in BBO crystal. The minimum detection limit was less than 1*10^<-6> Pa. As a proof for the specular reflection, we tried to measure angular distributions of hydrogen molecules through a Pt capillary. At present, the measurement was unsuccessful mainly due to the lack of sufficient pumping speeds in the vacuum system. The refinement of the vacuum pumps are going to be made.(3) Direct measurement of angular distribution of scattered molecules by molecular beam techniqueA molecular beam apparatus was developed in Tsukuba University and applied to the angular distribution measurement of modified metal surfaces. The specular reflection of Helium and Argon was demonstrated with very small diffuse scattering component. The combination of REMPI and molecular beam scattering apparatus is being developed. Less