The European Solar Telescope (EST)
EST performances requirements
4.2.1 | Field of view | 2´x2’ (goal 3´x3’). 3’x3’ Mosaic mode with optimal resolution in 1’x1’ patches NOT CONSIDERED FOR OPTICAL DESIGN (implies moving the telescope FoV) |
4.2.2 | Total throughput | >10% (30% telescope; 30% instruments) |
4.2.3 | Wavelength coverage | 390nm to 2.3μm (goal 350 nm to 2.3μm) with AO correction (Coudé focus) 315 nm to 20 μm without AO (Nasmyth focus) |
4.2.4 | Light distribution | Configurable with different fractions of light going to different instrument channels |
4.2.5 | Photon flux | > 2.106 photon/(pixel·s) instrument detector plane |
4.2.6 | Polarimetric sensitivity | 3.10-5 in S/I, S any stokes parameter |
4.2.7 | Polarimetric accuracy | Accuracy to know crosstalk between Stokes parameters |
4.2.8 | Scattered light at 500nm | < 10 % at 1” distance from the scattered light source on the science focal plane, < 1% at 5” distance Coronal observations, flux from the observed line >1 ADU before the background saturates detector |
4.2.9 | Sky coverage | Ecliptic above 10º on the horizon (goal full sky) |
4.2.10 | Observable radius away from the Sun | 200” from the solar limb >5 º (goal >2º) away from the Sun avoiding solar illumination |
4.2.11 | Image stability | 0.004”/10s (goal 0.003”/10s) with closed loop AO. 0.05arcsec/10s without closed loop AO |
4.2.12 | Image scanning step | Time<0.1s |
4.2.13 | Image scanning repeatability | 0.002´´ Spectrographs 1” (TBC) mosaic mode for BB and NB imagers |
4.2.14 | mage scanning stability | 0.01” over 1 hour |
4.2.15 | Absolute pointing accuracy | <3” |
4.2.16 | Open loop tracking accuracy | <1” /10minutes |
4.2.17 | Image quality with closed loop MCAO | SR500nm=0.3 (TBC) for 1´FoV and SR500nm=0.4 (TBC) for 30”FoV for r0>20cm. SR500nm=0.15 (TBC) for Ø1´FoV and SR500nm=0.25 (TBC) for Ø30”FoV for r0>10cm |
4.2.18 | Closed loop MCAO for near-limb observations | AO low order mode for observations near the limb, using Hα images. Performances TBD |
4.2.19 | Image quality without closed loop AO | Image quality degradation <10% seeing conditions for good seeing conditions (r0 =20cm at 500 nm) |
4.2.20 | Data flow | Data flux 200GB/sec Data volume 275PB/year |
4.2.21 | Maximum time between image acquisitions in mosaic mode | 2s for contiguous subfields 6s for non contiguous subfields |
(Table from L. Cavaller (IAC & GranTeCan) & the EST project)