1. Demetrio Magrin INAF – Astronomical Observatory of Padova demetrio.magrin@oapd.inaf.it Optical Design Catania, 11/06/2014

2. Outlines  Design parameters (Definition phase)  Nominal Baseline (Definition phase)  Nominal Performances (EE, spot diagram, PSFs, vignetting factor)  Sensitivity and thermal analysis  Breadboard – Prototype  New (Last…) Baseline  Open Issues

3. Spectral range500 – 1000 nm Entrance Pupil Diameter120 mm Working F/#2.06 @ 700 nm Field of View1151.5 degree 2 Image quality 90% Enclosed energy < 2×2 pixel 2 over 1108.3 degree 2 Maximum Field Distortion5.043% Plate scale15 arcsec/pixel Pixel size18 micron CCD format4510×4510 (×4) pixel 2 FPA size164.36 mm (2 mm CCDs gap) Optical elements weight  5 Kg (<6 Kg) Working Temperature-80°C Working Pressure0 atm Design parameters

4. Nominal Design Definition phase (18/03/2011) BK7 (G18) S-FPL51 N-KZFS11 CaF2 S-FPL53 KZFSN5 BK7 368 mm 196.2 mm

5. RThicknessGlassKa4a4 a6a6 ShapeDiameter (mm) window S1infinity6.000 BK7G18circular 190 S2infinity2.000190 Lens 1 S3177.85723.000 S-FPL51 -3.6813.605E-8-4.020E-12 circular 178 S4infinity27.351178 Lens 2 S5795.8557.000 N- KZFS11 circular 142 S6135.94356.975130 Lens 3 S7151.69723.000 CAF2circular 114 S8-225.53659.886116 Lens 4 S9-742.20017.000 S-FPL53circular 130 S10-139.24116.240131 Lens 5 S11-101.1945.000 KZFSN5circular 129.6 S12-144.005115.547135.4 Lens 6 S13-103.0835.000 N-BK7 (G18) circular 154 S14infinity4.000184 FPAS15infinitysquare Nominal Design Definition phase (18/03/2011)

6. Aspheric surface S-FPL51 Maximum deviation from BFS  1.050 mm See R.Ragazzoni presentation

7. Enclosed Energy 2x2 pixels G0V + detector QE

8. -40 micron+40 micron Enclosed Energy (through focus)

9. Spot diagrams and FoV 13.6 deg, 13.6 deg 14.3 deg, 14.3 deg 4x4 pixels

10. About vignetting Natural vignetting 7.5% at the edge of the ‘in spec’ FoV 9.0% at the edge of the full FoV

11. About vignetting Mechanical vignetting 4.2% at the edge of the ‘in spec’ FoV 6.4% at the edge of the full FoV

12. About vignetting Natural + Mechanical vignetting 11.7% at the edge of the ‘in spec’ FoV 15.4% at the edge of the full FoV

13. Polychromatic PSFs PLATOSim

14. ElementDecentering (+/- in micron) Tilt (+/- in degrees) L1800.07 L21000.05 L3300.03 L4600.03 L5600.05 L61000.10 Sensitivity Analysis Optical elements defocus  30-50 micron Merit Function: 80%EE< 2×2 pixel 2 over the corrected FoV

15. Thermal Analysis In the case of the of a uniform change of the temperature the optical system has 2 C of tolerances without the need of refocusing. With a temperature change of 10 C the nominal performances are still recoverable by applying a defocus through the three resistors. In the case of temperature gradient around the nominal temperature, the optical system maintain the nominal performance with a  T=5 C without the need of refocusing. While the performances are recoverable by applying a defocus in the case of a  T=10 C.

16. BreadBoard/Prototype Design The baseline design has been modified to allow the SESO tools adaptation (surfaces curvatures) and to facilitate and to speed up the manufacturing and mounting processes (some thicknesses and apertures have been increased). For procurement reasons, the glass of L5, KZFSN5, has been substituted by N-KZFS5. (J.Farinato / V.Viotto / M.Bergomi presentations)

17. 1)A physical stop in front of L3 (at about 2.84 mm edge to edge). 2)New weights for the wavelengths used in the Zemax merit function provided by P. Levacher - P. Bernardi. 3)Change the glass of L5 from KZFSN5 to N- KZFS5 (almost no optical impact and facilitate the procurement). 4)Change the thicknesses of L5 and L6 from 5mm to 7mm (all the industries suggested to increase these numbers). 5)Change on all lenses apertures from 1mm to 2mm with respect to the clear aperture. It should help to minimize the mechanical vignetting. My last ‘New Baseline’… 21/05/2011

18.  Data mining… (about 3 years to resurrect).  Converge on a well-identified design to use as baseline.  Optimize the design for new/modified requirements. Plate scale, PSF size, window material and thickness, 2 F-TOUs dedicated design.  Perform a detailed manufacturing/alignment tolerances and consolidate sensitivity/thermal analysis. RUAG warnings: the design is tight/ de-spacing tolerances are sub-micron.  Double-check performances in terms of EE/Simulator  Contact SESO and discuss the upgrade from breadboard to prototype with the related implications. Open Issues