Study on the Interaction of Polarized Atomic Hydrogen Beam with Solid Surfaces

点击翻译按钮获取中文摘要

Main subject of this project is the development and application of novel experimental techniques for the study of magnetic interaction of atoms and molecules with solid surfaces. The techniques developed in the project is divided into following three items.1. Atomic beam scattering of polarized atomic hydrogen The generation of high intensity atomic hydrogen beam and the detection of scattered atomic hydrogen were studied. Atomic hydrogen was evolved in a RF discharge-tube and the selection of its spin state was made by using a hexapole magnet. To keep the focusing of atomic hydrogen constant irrespective to its energy, we have developed a linear translator of the magnet system. The detection of atomic hydrogen was made by using a thermistor device. The operating condition and its limitation were studied. A preliminary measurement of reactive scattering of atomic hydrogen with a graphite surface was made at several temperatures.2. Measurement of the polarization of adsorbed atomic hydrogen To apply the beam-foil spectroscopy to the measurement of the poralization of adsorbed atoms, we have studied the ionization process of adsorbed atoms under irradiation of intense pulse laser. A method for the evaluation of the absolute intensity of ionized atoms was newly developed and was named "conductance modulation method".3. Measurement of ortho-para conversion of adsorbed hydrogen molecule. The rotational excitation of hydrogen was measured by using low-energy electron loss spectroscopy. The conversion rate was measured for several sufaces as follows: Ag(111), Xe/Ag(111), O^2/Ag(111).