Time Resolved Electron Energy Loss Spectroscopy of Surface Kinetics

表面动力学的时间分辨电子能量损失谱

• 批准号: 8714616
• 负责人: Wilson Ho
• 金额: $ 27.23万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-01-15 至 1991-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8714616&HistoricalAwards=false
• 关键词: Time; Resolved; Electron; Energy; Loss

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.

本研究项目的主要目标是在分子水平上对气体-表面相互作用的动力学和机理有详细的了解。利用时间分辨电子能量损失谱（TREELS）结合快速温度和压力扰动研究了吸附质化学键性质的变化。这种激发-探针技术可以研究广泛的表面过程，包括吸附/解吸、解离和吸附质的反应。更具体地说，拟议的项目将处理下列领域的问题：碱促进解离和反应，2。3.杂质对表面动力学的影响；合成反应，和4。电子和光子诱导的反应。将实验时间分辨率从毫秒扩展到微秒范围。除了为TREELS提供更快的96通道多检波器和数据采集电子设备外，还可以通过在脉冲分子束中添加斩波器和用微秒脉冲激光直接加热来实现更快的压力和温度扰动。脉冲电子源将由负电子亲和砷化镓光电阴极产生。