TAO is available and tested over sunspots and granulation with good results over significantly long periods of time (seeing dependent).

• A slowed-down (100Hz) version of the same system can be used to stabilize Mercury.
• At the moment it is not possible to use the AO over the solar limb (or for neighboring prominences).

In this mode, up to 4 (old) EMCCD Andor iXon camera (512×512) and up to 2 (new) Andor Zyla (2kx2k) cameras are available. Both 6 cameras can be setup and used at the same time (with their respective specs), in accordance with the SP2 output physical limitations. More information about the MTR2 spectrograph.

In this mode, 3 cameras (hence 3 wavelengths) at most are available, from the above list. It is possible to combine polarimetric and non-polarimetric cameras. THEMIS polarimetric analysis scheme is based on a full-Stokes analyzer located at the F1 prime focus. For any solar polarization state to measure, the output of the analyzer is made of dual superimposed complementary linear polarizations. Thanks to THEMIS “polarization friendly” new optical scheme, this output travels through the telescope and arrives unperturbed on the spectrograph cameras. Just in front of the camera, a Wollaston splitter separates the beam into complementary Stokes components to form the spectral focal plane. More information about the MTR2 spectrograph.

Regarding the available analysis software:

• A Stokes map quick-look is now available.
• Thanks to V. Bommier, a basic magnetic field inversion software package (running locally in IDL) is available.

It is running concurrently with the spectrograph. Current setup is for 656 nm (red), but this can be changed optionally to G-band or other.

• The optical diffusion problem that was detected in Sept 2024 (mostly affecting the He D3 observations) has been identified and corrected (November 2024).
• The data acquisition issue in polarimetric modes was tracked down to a bad synchronisation between the analyzer rotation and the camera exposure. This has been solved at the cost of slowing down the acquisition loop (roughly a factor 2 slower). This issue has been affecting all the September 2024 runs.

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