Contrib. Plasma Phys. zyxwv 33 (1993) zyxw 5/6, 523-526 X-ray Spectroscopic Measurements of 1 Ons KrF Laser Produced Plasma Isao MATSUSHIMA, Hidehiko YASHIRO, Toshihisa TOMIE, Isao OKUDA, Yuji MATSMOTO, Eisuke MIURA, Yoshiro zy OWADANO Electrotechnical Laboratory, 1-1-4, Umezono, Tsukuba, 305, Japan Abstract Laser produced plasma generated by lOns KrF laser pulses has been investigated by means of X-ray spectroscopic measurements. Electron density and temperature have been obtained with one-dimensional space resolution. The electron temperature was determined from the slope of free-bound continuum to He-like ions. The electron density was estimated from the opacity of resonance line emissions and also from Stark broadening. The observed profiles agree with one-dimensional hydro-dynamic simulation result. 1. Introduction The KrF laser is considered to be a promising candidate for the reactor driver of inertial confinement fusion zyxwvu [ 11 because of high efficiency, scalability and short wavelength. Furthermore, its broad bandwidth is effective in smoothing the target irradiation profile [2]. Nevertheless, an optimized tailored pulse is desired to achieve high-gain KrF laser fusion. The total pulse duration will be longer than 10ns. Therefore, laser-plasma interaction physics under long pulse irradiation of short wavelength laser should be established. In this paper, we report temperature and density profiles of the plasma created by lOns KrF laser irradiation. The profiles were obtained experimentally with x-ray spectroscopic measurements. The electron temperature was determined from the slope of free-bound continuum. The electron density can be estimated from the opacity of resonance line emissions and also form Stark broadening. The observed profiles were compared with one-dimensional hydro-dynamic simulation results. These results suggest that the advantage of short wavelength laser is effective even in the long pulse irradiation.