Opacity effect on extreme ultraviolet radiation from laser-produced tin plasmas

Opacity effects on extreme ultraviolet (EUV) emission from laser-produced tin (Sn) plasma have been experimentally investigated. An absorption spectrum of a uniform Sn plasma generated by thermal x rays has been measured in the EUV range (9-19 nm wavelength) for the first time. Experimental results indicate that control of the optical depth of the laser-produced Sn plasma is essential for obtaining high conversion to 13.5 nm-wavelength EUV radiation; 1.8% of the conversion efficiency was attained with the use of 2.2 ns laser pulses.</p

Angular distribution control of extreme ultraviolet radiation from laser-produced plasma by manipulating the nanostructure of low-density SnO 2 targets

金沢大学先端科学・社会共創推進機構We have found that the divergence of a relatively monochromatic extreme ultraviolet (EUV) emission from a laser-produced plasma can be manipulated by changing the target morphology which is a porous low-density tin oxide (Sn O2) structure. The fundamental light of a Nd-YAG laser was irradiated on the target with laser intensity of ∼ 1011 W cm2 and pulse duration of 10 ns. The nanostructure and density of the targets were tuned by a combination of colloidal polymer template and sol-gel processes [Gu, Nagai, Norimatsu, Fujioka, Nishimura, Nishihara, Miyanaga, and Izawa, Chem. Mater. 17, 1115 (2005)], which has a merit in large-scale preparation. When the target has an open cell nanostructure, the EUV emission directed predominantly along target normal, while a closed cell target exhibited divergent emission. The angular distribution may be affected by the orientation of the microstructured initial target, and this phenomenon can be applied to wavefront control of EUV emission. © 2006 American Institute of Physics.Embargo Period 12 month