摘要
本文介绍由复旦大学激光化学实验室建造的一台多功能分子束实验装置,该装置的主要部份包括:配有三级差分抽气系统的CW超声分子束源,在中心部位装有可转动固体样品架的主室,放置四极质谱计的探测室,以及计算机数据采集系统.谈装置中的束源是固定的,而用于测量产物角分布的探测室是可转动的.其主要特色在于探测室围绕反应中心转动时,二台差分抽气用的离子泵是固定不动的,探测室与离子泵机组之间采用可弯曲的不锈钢波纹管软连接,从而使其结构紧凑,造价低廉,此外,该装置还可用于交叉分子束实验,分子束光裂解以及分子束弛豫谱等研究.
A versatile molecular beam apparatus constructed by Laser Chemistry Laboratory at Fudan University is presented. It consisted of a supersonic molecular beam source with a 3-stage differential pumping system, a reaction chamber with a rotatable sample holder at the center, a quadrupole mass spectrometer situated in the detection chamber and a computerized data acquisition system. A fixed beam source arrangement with a rotatable detection chamber is used for measuring the angular distributions of reaction products. The novel feature of this apparatus is that the detection chamber is connected with two fixed ion pumps for a two-stage differential pumping through two flexible stainless steel bellows. Thus the detection chamber can be rotated around the reaction center. This compact apparatus can be employed to measure the mass selected time-of-flight spectra and determine the mass, velocity and angular distributions of reaction products. This versatile molecular beam machine can be used to do experiments on crossed molecular beams, molecular beam photofragmentation and molecular beam relaxation spectroscopy.
