We compared cadmium, copper, gold, and zinc targets to stainless steel for laser-produced plasma pumping the Xe(2+) 109 nm laser. A unique target geometry allowed us to measure the laser output using two materials under identical conditions. Small signal gain coefficients and maximum output powers are presented for each material relative to stainless steel; we observed about a 20% improvement in the gain coefficient and a 112% improvement in total energy using a cadmium target. This increase probably results from an improved overlap of the laser-produced plasma emission spectrum with the Xe inner shell 4d photoionization cross section, although published data to support this hypothesis are scarce and inconsistent.

This work was sponsored by the U.S. Air Force Office of Scientific Research and the National Science Foundation.