Laser-heated discharge plasma extreme ultraviolet source

A novel extreme ultraviolet source design is considered, in which an underdense pinch plasma is locally heated by a laser and the raised temperature in the heated region causes excitation followed by 13.5 nm emission. The concept is illustrated with a lithium Z -pinch transversely irradiated by a carbon dioxide laser. Absorption, excitation, thermal conduction and flux-limited radiation are considered in a simple model that predicts up to 40% conversion efficiency (4π sr) from 10.6 µm light to 13.5 nm light in the irradiated region. The effects of source size on scaled source power and efficiency are discussed. Experimental data are presented on a lithium Z -pinch plasma suitable for this source.