Influence of laser intensity and pulse duration on the extreme ultravioletyield from a water jet target laser plasma

Extreme ultraviolet (EUV) emission in the 11-15 nm wavelength range from a thin liquid water jet target under illumination with a high repetition rate , high average power laser (Nd-YLF) has been studied. To find the optimum c onversion efficiency of laser light into EUV radiation, different laser par ameters were applied. The laser intensity was varied between 10(11) and 10( 15) W/cm(2), and pulse duration in the range from 30 ps to 3 ns. A maximum conversion efficiency of 0.12% in 2.2% bandwidth and 4 pi steradian at 13 n m was achieved at a repetion rate of 250 kHz, and a strong dependence of th e conversion efficiency on both laser intensity and pulse duration was foun d. (C) 2001 American Institute of Physics.