A Study of Reaction and Scattering of Alkali-earth Metals by Using Crossed Molecular Beams.

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The purposes of this study are to develop new method and to measure the cross-section for the formation of alkali-earth compound molecules in gas-beam reaction and cross-beam reaction as a function of the energies of the reagent and reactant molecules. These molecules are fortunately good candidates for the laser study of reaction dynamics.1) The cross-beam of Ar and metastable Ca in ^3P state was studied to meseasure the cross-section for energy transfer between fine-structure levels of Ca ^3P state. A pumping laser puped out all atoms form a certain J level and the degree of repopulation by collision of Ar beam was meseasured by a probe laser to determine the cross-section for energy transfer.2) We have measured the level to level vibrational-rotational energy transfer rate in I_2- He supersonic molecular beam. The intensities of fluorescence induced directly by laser and indirect fluorescence from the energy transfered levels were measured as function of exciting position and observing position along molecular beam and the rates for the level to level relaxation were determined from contour analysis of the observed spectra.3) The temperature and the pressure are varying drastically, say three orders in magnitude, along the expanding jet. We have proposed that we should use this system to study the energy dependence of reaction cross-section. We have constructed a discahrage free expansion jet aparatus and many radical species were spectroscopically observed. We have developed a measurement system for spacially resolved spectroscopy to strudy reaction dynamics in this system.4) Diode laser probe system for state analysis in reaction study and suitable for detection of atomic beam has been developed by using diode laser of which tunability was 30 mn.