High-resolution spectrum of xenon ions at 134 nm

The spectrum of xenon excited in a low-inductance vacuum spark was photographed at high resolution in the region of 9.5–15.5 nm. The observed transitions were identified as belonging to ions from Xe⁸⁺ to Xe¹³⁺ . In the region of importance for extreme-ultraviolet lithography around 13.4 nm, the strongest lines were identified as 4d⁸–4d⁷5p transitions in Xe¹⁰⁺ . The identifications were made by use of energy parameters extrapolated along the isoelectronic sequence.