Velocity imaging - Applications in molecular oxygen photophysics

Velocity imaging(1), an improvement of the ion imaging method(2), is described and applied to a study of photodissociation of molecular oxygen. The electrostatic immersion lens introduced in this technique has the special property of projecting out the velocity information of a fragment formed in a photodissociation process, independent of the initial position of the fragment. This results in better image quality, thus more detailed information on the dynamics of collision and half-collision events. Photodissociation of molecular oxygen in the region of the Herzberg and Schumann-Runge continua using velocity imaging is discussed.