Experimental Measurements of Cumulative Excitation and Ionization in Atomic and Molecular Gases.

Abstract

Abstract : This work described an experimental effort to determine the electron collision excitation and ionization cross sections of metastable atoms and molecules. The ionization cross section measurements were not successful. Excitation cross section studies were productive, and a number of direct and two-step cross sections were obtained. Measurements of several direct excitation cross sections of xenon in the range from 6000 A to 9000 A were made. These relative excitation functions compare favorably to data in the literature where it exists, and offer some insight to the lasing processes of the 5d levels. Measurements on the cross sections from the helium 2(3)S state to the 3(3)S, 3(3)P, 3(3)D, 4(3)S, and 4(3)D states were obtained. Results indicate that the 3(3)D level has the largest cross section. Evidence for the existence of the two-step cross section in Krypton has also been observed, but there is insufficient direct cross section data available to estimate the magnitude of the two-step process. An experimental investigation was performed to determine the cross sections of the relevant transitions. Excitation functions of several 5p, 6p, 7s and 5d states of Krypton have been measured.