摘要
介绍了自行设计和加工的激光-分子束-表面散射装置，并对超高真空转动密封结构作了详细描述。差分泵浦的超音速分子束对准样品中心，射入超高真空主室。样品架安放在主室中央，四极质谱检测器可绕样品转动，用来测量表面散射分子的平动能及角分布。三个石英窗口作为激光窗口，可用LIF或MPI方法来测量表面散射分子的内能态分布，也可用于研究表面光化学。最后给出了分子束发散角及室温时CH2I2在Ag（110）表面用308um激光光解碎片碘的TOF谱的测量结果。
A molecular beam apparatus to study molecule-surface dynamics is discribed in detail in this paper. A supersonic bearn source in a differently pumped source chamber is connected to the UHV main chamber, in the center of which, a crystal manipulator is located- The molecular beam aims at the center of the sample surface,and a rotatable quadrllpole mass sPectrometer detector arround the spamle is arranged for measuring the translational energy and the angular distribution of the scattering species from the surface. Three quarz windows are designed for probing the internal state distributions of the species scattered from the surface with LIF technique.A special sealing is designed for the UHV main chamber under the condition of rotation of the detection chamber. lt is differentially pumped outside the main chamber. Surface analysis and cleaning inethods on this apparatus are briefly introduced.A MPI detection is considered as well. This setup can be also applied to study surface photochemistry,including laser induced desorption,dissociation and other reaction of the adsorbates on surfaces,with direct irradiation of a laser beam at the sample.As an exarnple of application,the divergence of the supersonic molecular beam and the TOF sPectrum of the fragment I from the photodissociation of CH2I2 on Ag(110) surface at room temperature at 308nm are presented.
出处
《真空科学与技术》
CSCD
1995年第1期14-22,共9页
Vacuum Science and Technology
基金
国家计委资助
关键词
激光
分子束
表面散射
表面光化学
Supersonic molecular beam,Translational energy,Angular distribution,Surface photochemistry
