The WUVS spectrographs assembly includes the instruments VUVES, UVES, and LSS, which are being developed by Russia. Since 2011 its new design and construction is led by the Institute of Astronomy of the Russian Academy of Sciences in collaboration with several institutes of the Russian Academy of Sciences (RAS) and the Russian industry.
The geometrical stability of the spectrograph is provided by titanium heat pipes, all heat sources inside the spectrographs are connected to the outer wall by additional heat pipes. Detectors cooling system consists of a large external radiator and an isolated heat pipe connected to detectors cold fingers. The recent progress in the technology for developing CCD detectors, has permitted to define a custom design for WUVS CCD detectors that are manufactured by e2v.
WUVS preliminary design and Structural Model are shown below.
WUVS (WSO-UV Spectrograph) consists of two high resolution spectrographs (R=50000) covering VUV range 115-176 nm and the UV range of 174-310 nm, and a long-slit spectrograph (LSS, R=1000) covering a wavelength range of 115-310 nm.
In the new optical design basic schemes of the VUV and UV spectrographs are quite similar. Instead of UV prism cross disperser in UV spectrograph new design is based on the cross disperser combined with UV camera mirror (identical to the VUV spectrograph). Segmented toroidal gratings are used in the LSS design.
Expected efficiency of WUVS spectrographs is shown in the next plots.