Grating Spectropolarimeter

Four configurations of grating spectrographs are presented to fulfill the EST requirements:

• Long-slit Standard Spectrograph, LsSS,
• Multi-Slit Multi-Wavelength Spectrograph fed with an Integral Field Unit, IFU-MSMWSP,
• Tunable Universal Narrowband Imaging Spectrograph, TUNIS,
• Multi-channel Subtractive Double Pass, New Generation, MSDP-NG.

These four configurations use the same spectrographs, hereinafter named as “main spectrographs”: two for the visible range of the spectrum and another two for the near-infrared. By inserting the adequate optical elements, each spectrograph can independently operate in any of the above mentioned configurations. The design drivers for the main spectrographs are:

• each main SP shall be designed with commercial gratings,
• each main SP shall be as compact as possible,
• each main SP shall be a static module, common to the four spectrograph configurations mentioned above,
• the combination of these main SPs shall cover simultaneously all the solar lines observations specified in the Science Requirements Document.

A fifth option, under design and construction into the framework of SOLARNET project, is based on a microlens-fed spectrograph.