Potential+Barrier+Effects+in+Two-Photon+Ionization+and+High-Order+Harmonic+Generation+in+the+X-Ray+Regime

Potential Barrier Effects in Two-Photon Ionization and High-Order Harmonic Generation in the X-Ray Regime

Anthony F. Starace The University of Nebraska-Lincoln

Potential barrier effects are well-known features of atomic photoionization cross sections [see, e.g., A.F. Starace, "Theory of Atomic Photoionization," Handbuch der Physik, 31, ed. by W. Mehlhorn (Springer-Verlag, Berlin, 1982), pp. 1-121]. I shall present recent results showing that potential barriers also greatly influence two-photon ionization processes as well as high-order harmonic generation from plasmas in the soft x-ray regime. Furthermore, they may allow extension of table-top harmonic generation for atomic targets into the soft x-ray regime.