Time Resolved Electron Energy Loss Spectroscopy of Surface Kinetics

该研究项目的主要目标是获得一个详细的 在分子水平上理解 气体与表面的相互作用。 联合国系统性质的变化 用时间分辨电子方法研究了吸附质的化学键 能量损失谱（TREELS）与快速温度耦合 和压力扰动。 广泛的表面处理 可以通过这种激发探测技术来研究，包括 吸附/脱附、解离和吸附物的反应。 更具体地说，拟议项目将解决以下问题： 以下几个方面：1. 碱促进的解离， 反应，2。 杂质对表面动力学的影响，3. 合成反应，和4. 电子和光子感生 反应. 实验时间分辨率从 毫秒到微秒的范围将被承担。 此外 来改进一个更快的96通道多路检测器和数据采集器 电子TREELS，更迅速的压力和温度 扰动将通过增加斩波器来实现， 脉冲分子束和微秒直接加热 脉冲激光，分别。 脉冲电子源将被 由负电子亲和势GaAs光电阴极产生。

The main goal of this research project is to obtain a detailed understanding at the molecular level the kinetics and mechanisms of gas - surface interactions. Changes in the nature of the adsorbate chemical bond are studied by time resolved electron energy loss spectroscopy (TREELS) coupled with fast temperature and pressure perturbations. A wide range of surface processes can be studied by this excite - and - probe technique, including adsorption/desorption, dissociation, and reaction of adsorbate. More specifically, the proposed project will address problems in the following areas: 1. alkali-promoted dissociations and reactions, 2. effects of impurities on surface kinetics, 3. synthesis reactions, and 4. electron and photon induced reactions. Extension of the experimental time resolution from millisecond to microsecond range will be undertaken. In addition to improvise a faster 96-channel multidector and data acquisition electronics for TREELS, the more rapid pressure and temperature perturbations will be achieved by the addition of a chopper to the pulsed molecular beam and direct heating with a microsecond pulsed laser, respectively. A pulsed electron source will be generated from a negative electron affinity GaAs photocathode.