Grazing incidence spectrograph-monochromator with a focusing toroidal mirror.

The use of a toroidal mirror in front of a spherical grating spectrograph working at grazing incidence provides a system that is stigmatic in one dimension in the extreme ultraviolet (XUV) region and allows spectroscopy with space resolution. The system is optimized for spectral and spatial resolution and for efficiency. By using three toroidal mirrors mounted on a suitable turret and a new model of grazing incidence spectrometer, the system is capable of covering the whole XUV region. All the necessary movements are internal to the system and do not involve the source. Two examples are treated, one for a diagnostic study of laser-produced pellets and another for observation of large plasma machines.