H-<sub> 2 </ Sub> Valence Shell Excited By Fast Electron Impact

The main contents of this dissertation are divided into two parts: the first is to develop a new deconvolution method for the electron energy loss spectrum of diatomic molecule; the other is to study the generalized oscillator strengths of the vibronic states of B 1Σ+u,C 1Πu of hydrogen using an angle-resolved fast-electron-energy-loss spectrometer.In chapter 1, the principles and structures of angles- resolved fast- electron-loss spectrometer, as well as the basic conceptions of optical oscillator strength, generalized oscillator strength, and deferential cross section, are described. Besides, the gas mixture method for measuring the generalized oscillator strength is described briefly.In chapter 2, a new deconvolution method for the electron energy loss spectrum of diatomic molecule is proposed. In this method, the fitted energy positions are locked on the accurate spectroscopic data, and the calculated Franck-Condon factors, which are adjusted by a quadratic function, are used. Therefore the requirement of the precision for the Franck-Condon factors is relaxed. Then the undermined parameters in the deconvolution procedure are reduced dramatically . Also the precision of the fitted results is improved. The program of this method has been compiled by the mathematics language, and the optimized algorithm in the fitting procedure avoided a lot of integral calculations. The program was used to deconvolved the electron energy loss spectrum of H2, and the optical oscillator strengths for the vibronic states were determined. The good agreement of the present results with the previous experimental and theoretical ones shows the validity of the present proposed method.In chapter 3, the generalized oscillator strengths for vibronic bands of B 1Σ+u,CΠu of hydrogen were determined at an incident electron energy of 2500 eV, the energy resolution of 75meV and in the scattering angle range of 1.5°-6°with an interval of 0.5°. The momentum transfer dependence behavior of Franck-Condon factors for the vibronic bands of B 1Σ+u,C 1Πu were investigated. For the first time, the generalized oscillator strengths for v ' = 0 ? 17of B 1Σu+and v ' = 0 ? 5 of 1CΠu were reported. The present experimental results were compared with the previous works.