Collision Spectroscopy. I. Analysis of the scattering of He+ by Ne and Ar

Experimental data on the differential scattering of He+ by Ne and Ar in the energy range from 10 eV to 100 keV are plotted in a reduced coordinate system suggested by a scaling law for the forward scattering. The resulting curves are used to determine the interaction potential. The repulsive interaction dominating at higher energies shows pronounced shell-structure effects; leading to the deduction of the screening constants for the L and M shells of Ar and for the K and L shells of Ne. At lower energies a polarization attrac­tion appears, allowing deduction of the polarizabilities of Ne and Ar. A simple analytic potential is constructed, including a polarizability term appropriately damped inside the outer shell, which fits the data over the entire range. In addition to the pure elastic scattering, effects of inelastic interactions are diagnosed. A prominent curve crossing is located and the scattering pattern arising from it is interpreted by a semiclassical theory. In collisions with closer encounters, a different type of inelastic. process appears which apparently involves a more intense coupling than the curve crossing and which appears to open up a number of competing inelastic channels.Supported in part by the National Aeronautics and Space Administration and by the U.S. Army Research Offic

Demonstration of efficient full aperture Type I/Type II third harmonic conversion on Nova

Type I/Type II third harmonic conversion has been implemented at the 74 cm aperture of the Nova laser system. We discuss the performance capabilities and alignment issues of this scheme for Nova relative to conventional Type II/Type II conversion. 3 refs., 2 figs