Versatile grazing incidence spectromonochromator for the xuv region

Abstract

A new type of grazing incidence spectromonochromator, which can serve equally the need of synchrotron radiation research and plasma research, is presented. Making use of the Rowland circle mounting, it is based on the two‐grating principle that proved to be very efficient in separating higher orders in a previous prototype. A new mechanical system, well adapted to the current possible uses, has been incorporated. The apparatus can work as a spectrograph or as a monochromator, with one or two gratings, with a mobile or a fixed exit slit. In the spectrograph mode it can be used either with a photographic chamber or with a photoelectric detector. The incidence angle on each grating can be varied continuously and the gratings can be easily changed and readjusted entirely with visible light. The adaptation of the apparatus to the synchrotron radiation emitted by the ACO storage ring is described and the first results of tests, concerning mainly its order‐sorting capability, its resolution, and the absolute flux of photons available, are presented.