SPACE-RESOLVED EXTREME-ULTRAVIOLET (XUV) SPECTROSCOPY USING A TOROIDAL MIRROR

Abstract

In order to collect radiation from a distant light source and to compensate astigmatism, a toroidal mirror is often placed in front of a grazing-incidence spectrograph. In this study, characteristics of space-resolved spectra obtained with such a system have been investigated using a ray-tracing analysis. The following was found: in the stigmatic focal region of the spectrum, the spatial resolution along the sagittal direction is excellent but that along the meridional direction is poor; on the other hand, in the astigmatic wavelength region, the trend is reversed, i.e., the spatial resolution along the sagittal direction is poor but that along the meridional direction is good, particularly in the wavelength region which is far from the stigmatic focus. The method was successfully applied to the space-resolved spectroscopic study of a capillary discharge plasma. (C) 1995 American Institute of Physics.