Electron diffraction studies of laser-pumped molecules. I. Characterization of system and analysis of data

Abstract

The feasibility of investigating the vibrational excitation of laser‐pumped molecules in a supersonic jet by electron diffraction is investigated. Studies of SF6 confirm that diffraction patterns can be measured, reproducibly, to a part per thousand of the total intensity, or better, and hence can be analyzed to yield useful information about laser‐induced changes in intramolecular motions, provided adequate account is taken of certain systematic errors. Procedures for discriminating between bona fide and spurious signals are outlined. Methods are described for characterizing the gas flow and density profile in the microjets issuing from a small tubular nozzle, and for measuring the distribution of radiant energy in the focused infrared beam used to irradiate the gas jet