Abstract
As for deposition-free-targets, cryogenic Xe and Li targets of laser- produced-plasma have been studied for extreme ultraviolet (EUV) light sources. A fast rotating cryogenic drum system, which can continuously supply a solid Xe target, has been developed. It successfully generated about 1 W of EUV power by continuous irradiation of Nd: YAG slab laser at 320 pps, with a maximum conversion efficiency of 0.9%. Experimental results for the Xe target of the double-pulse and short-wavelength irradiation have also been reported. In addition, a new Li target using a forced-recombination scheme was demonstrated. It was found that the maximum conversion efficiency was 2.3% with a laser irradiation of 532nm in Li planar targets. By using both direct EUV emissions and forced-recombination emissions, higher efficiency can be achieved.
