Measurement of the absolute cross sections for the electron collosion excitation of metastable states of rare-gases using a high-sensitivity FM-absorption methdo

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A sensitive and accurate method has been developed for the detection of the excited rare-gas atoms in the metastable and resonance levels using a diode laser as a tunable light source for the absorption measurement. Then, the hyperfine structures and line shapes of the absorption spectral lines of Ar, Kr, and Xe have been analyzed by scanning the wavelength of the laser and the collision broadening- and shift-coefficients have been derived, which are necessary for the derivation of the absolute densities of the excited atoms from the line absorption data.On the other hand, a set up for the electron swarm experiment has been constructed by improving the electron drift-tube equipped with an ultra-high vacuum system which can supply relatively high and stable photo-current for a long period. By compbining the drift-tube and the laser absorption technique we have measured the excitation coefficients for the metastable and resonance levels of Ne, Ar, Kr, and Xe as functions of the ratio of the electric field strength to the gas density.The measured excitation coefficients have been compared with the calculated results obtained from the Boltzmann equation analysis using a trial set of cross sections for each rare-gas. From the comparison absolute values of the cross sections for the excited levels have been determined.As for the application of the obtained excitation coefficients or the cross sections, we have tried to use those values in the simulations of gas discharges in mixtures of rare-gases with other gases which are used, e.g., for the plasma display for a color TV and the plasma CVD for the preparation of various thin films.