CONVERSION EFFICIENCIES FROM LASER-PRODUCED PLASMAS IN THE EXTREME-ULTRAVIOLET REGIME

The conversion efficiency of spectral emission from laser-irradiated s olid targets was investigated for short wavelength source development. The plasma brightness was quantified using absolutely calibrated dete ctors for 20 materials and spectra were obtained between 50 and 200 An gstrom. Laser parameters such as wavelength, pulse length, intensity, and spot size were systematically varied to establish a comprehensive database for source optimization. Qualitative differences in the under lying dominant emission features as a function of atomic number and la ser wavelength were observed that accounted for the relatively high sp ectral conversion efficiencies produced. In the specific case of Sn, a conversion efficiency greater than 0.8%/eV has been observed in the t echnologically important region of lambda = 134.0 Angstrom using a las er intensity of 1-2 X 10(11) W/cm(2).