We focused the beam of a high-repetition-rate capillary-discharge tabletop laser operating at a wavelength of 46.9 nm, using a spherical Si/Sc multilayer mirror. The energy densities significantly exceeded the thresholds for the ablation of metals. Single-shot laser ablation patterns were used in combination with ray-tracing computations to characterize the focused beam. The radiation intensity within the 2-μm -diameter central region of the focal spot was estimated to be ≈10<sup>11</sup>W/cm<sup>2</sup>, with a corresponding energy density of ~100 J/cm<sup>2</sup>.
© 1999 Optical Society of America
B. R. Benware, A. Ozols, J. J. Rocca, I. A. Artioukov, V. V. Kondratenko, and A. V. Vinogradov, "Focusing of a tabletop soft-x-ray laser beam and laser ablation," Opt. Lett. 24, 1714-1716 (1999)