GRIST instrumentation

The Grazing Incidence Solar Telescope (GRIST) as it is being studied by the European Space Agency (ESA) is briefly described: it is an extreme ultraviolet facility for solar observation with 1 arc sec spatial resolution in the wavelength range from 9 to 120 nm.Two examples of focal plane instruments are illustrated: a normal-incidence stigmatic spectrograph using a toroidal grating recorded on an elastically deformed surface and a grazing-incidence stigmatic spectrograph using two toroidal elements: a mirror and a grating. If coupled with suitable array-type photoelectric detectors such spectrographs are capable of recording spectroheliograms in a very short time.Proceedings of the Conference Solar Physics from Space, held at the Swiss Federal Institute of Technology Zurich (ETHZ), 11–14 November 1980.