Abstract

A self-healing target for synchronous photopumping of extreme-ultraviolet (XUV) lasers with modest-energy pump lasers has been developed. Gold and other high-Ztargets, commonly applied to photopumped lasers because of high conversion efficiencies of soft-x-ray radiation, have limited lifetime because of ablation of target surfaces, A Hg-wetted Cu rod rotated in a liquid pool of Hg has served as an efficient high-Ztarget for synchronous excitation of a 109-nm Xe III Auger laser without permanent degradation of the Hg surface. The pump laser interacts only with the thin Hg coating, which is healed by continuous rewetting in the Hg pool, and thereby offers unlimited target lifetime for high-repetition-rate applications. The target was threaded (330-μm pitch) and was oriented at a 7.5° grazing angle to offer the traveling-wave geometry previously found¹ to reduce the pump-energy requirement and to support saturated gain in the Xe laser.

© 1993 Optical Society of America