Design and construction of an optical instrument for an analysis of the angular difference Doppler profile excited by controlled electron impact.

Analysis of the Doppler profile of the excited atomic fragment produced in electron molecule collisions have been found to be useful for the detailed investigation of molecular dissociation dynamics. A new optical instrument has been designed and constructed for such measurements. It has a collision chamber equipped with a rotatable electron gun and a gas cell, and a Fabry-Perot interferometer for a high resolution (0.01-0.07 A) analysis of the line profile. This instrument can successfully allow a determination of the translational energy distribution and the angular difference Doppler profile of the excited atomic fragment, and has been found to be useful and versatile.