Abstract

The careful measurement of the velocity of reactions products, both from unimolecular and bimolecular reactions, has produced large amounts of insight into the dynamics and energetics of chemical reactions. Time-of-flight measurement of the products of unimolecular reaction products give a measure of bond energies and the angular distributions speak to the spectroscopy of the parent molecule and the time scale of the dissociation. The measurement of the velocity of products of a bimolecular reactions, the so called "Newton Sphere" of the reaction, gives insight into the energetics and dynamics of the reaction. Recently, new techniques have developed that allow the combination of laser selective ionization to be combined with spatially resolved ion detectors to measure the velocity of a quantum state selected reaction product. These techniques are generally called "Ion Imaging" and the newest variation of these techniques uses electrostatic lenses to perform a transform of the image into velocity space. The use of the lenses improves the velocity resolution of the images significantly but at the loss of absolute size determination. There is magnification associated with the use of the new apparatus and therefore standards must be used to quantify the images. This technique is also useful for the moderate resolution measurement of the velocity of photoelectrons.

© 1998 Optical Society of America