Abstract

The storage ring free electron laser will make studies of multiphoton ionization in the vacuum ultraviolet possible. At relatively low laser intensities one can study two-photon resonant three-photon ionization of atoms in a regime where perturbation theory works well. In this regime cross sections for the multiphoton processes can be measured accurately and then used for sensitive, quantitative detection of atoms. At higher intensities higher-order processes such as multiple ionization can take place. The tunability, variable pulse length, and well characterized spatial distribution of the FEL will be important in unraveling the mechanisms of these processes.

© 1988 Optical Society of America