1. Progress meeting 4, 27.01.2006 Calibration Unit status at PM4 Andreas Kelz, Svend M. Bauer Uwe Laux, Martin M. Roth

2. 27.01.2006, PM4.2 CU product tree CONT & ARC Lamps, filters & shutters Integrating sphere & lens to mimic VLT pupil & beam various calibration masks PE + ICE (AIP + LAOMP)

3. 27.01.2006, PM4.3 CU Requirements Functional and performance requirementsFunctional and performance requirements: Flat field calibrationFlat field calibration Spectral calibrationSpectral calibration Image quality calibrationImage quality calibration Geometrical calibrationGeometrical calibration Light contaminationLight contamination Operational requirementsOperational requirements: Natural imposed environmentNatural imposed environment Operating modesOperating modes Lifetime requirementsLifetime requirements Reliability / Safety requirementsReliability / Safety requirements Maintenance / Interchangeability requirementsMaintenance / Interchangeability requirements Interface requirementsInterface requirements: Mechanical and thermal interfacesMechanical and thermal interfaces Electrical, communication and fluid interfacesElectrical, communication and fluid interfaces Optical interfacesOptical interfaces Software interfaces for details see: CU Technical Specifications Version: 2.3 from: 26/04/2005 VLT-SPE-MUS-14670-0022

4. 27.01.2006, PM4.4 VLT beam CU beam CU concept CU concept Calibration optics focal plane virtual lens pupil plane

5. 27.01.2006, PM4.5 CU basics – CU optics to replace and to simulate the VLT – One calibration relay lens (CRL) to mimic VLT beam (using a telescope objective). – An integrating sphere for homogenous illumination (to simulate flatfield screen). – Various calibration light sources (CLS) for white light and spectral illumination. -Precision masks at CU focal plane to calibrate instrument and to measure image quality.

6. 27.01.2006, PM4.6 55 mm80 mm 1200 mm1108 mm Top: VLT beam Bottom: CU beam (D=80mm, F=1200mm) Integrating Sphere (IS) = pupil plane Calibration Relay Lens (CRL) CU Focal Plane (CFP) CU design (Apochromat triplet K5 / CaF2 / K5)

7. 27.01.2006, PM4.7 546 nm 436 nm 707 nm 480 nm 644 nm pupil polychrom. VLT – focal plane spot diagramms on-axis off-axis -> 0.03mm

8. 27.01.2006, PM4.8 546 nm 436 nm 707 nm 480 nm 644 nm pupil polychrom. CRL – Apochromat (CaF2) spot diagramms on-axis off-axis -> 0.15 mm VLT Airy disk

9. 27.01.2006, PM4.9 CU with mechanics

10. 27.01.2006, PM4.10 CU dimensions 1.3 m 1.6 m ca. 80 kg

11. 27.01.2006, PM4.11 CLS – IS - CRL Lamps and Proximity Electronic in individual housings Flexible Light Guides to connect lamps to CU Integrating Sphere for homogenous illumionation Stray light baffles Calibration optics to mimic telescope

12. 27.01.2006, PM4.12 i.e. 6 lamps: Continuum Flat: Quartz halogen Arc lamps (pencil style): Hg, Ar, Ne, Kr Arc lamps (High Power): He, K, Cs, Cd, Rb, Hg Hollow cathode lamps: Th/Ar Fe/Ar/He Calibration Light Sources & PE boxes

13. 27.01.2006, PM4.13 CMW-CPE CU inner components: Calibration Mask Wheel and Pick-up Element

14. 27.01.2006, PM4.14 Pinhole mask MUSE pinhole mask: ~800 pinholes, 20 micron at 35x35 mm Precison and pitch Tolerance: +/- 1 micron Laser-manufactured (LMTB) mask: 1024 pinholes, 12 microns each at 1x1 mm

15. 27.01.2006, PM4.15 B3110 Calibration Unit opto-mechanical design – Location of CU on Nasmyth platform TBD – Removability of CU for GALACSI dismounting – Location of lamps and distance from CU to electronic cabinets CU: TBD – open issues

16. 27.01.2006, PM4.16 – CU optical design document: due at 3.Feb. includes: Finalized CU optical design, updated cost estimate, possible manufactures, Obtain quotes for CRL (estimate: ~ 10-15 kEuro) Selection and location of lamps – CU mechanical design document: due at 10. Feb. includes: Folded beam option, weights, proposed location options – Optical designer meeting at AIP (9.3. proposed) – Mechanical Designer meeting at IAG (31.3. proposed) CU: foreseen work

17. 27.01.2006, PM4.17 CRL – alternative design v1: Apochromat triplet made of: K5 / CaF2 / K5 v2: Achromat doublet made of: N-BK7 / F2

18. 27.01.2006, PM4.18 546 nm 436 nm 707 nm 480 nm 644 nm pupil polychrom. CRL – Achromat (BK7) spot diagramms on-axis off-axis -> 0.15mm VLT Airy disk

19. 27.01.2006, PM4.19 ~1.2 m Top: VLT beam (F/15) Center: CU beam v1 Bottom: CU beam v1p Integrating Sphere (IS) = focal plane 2 x Calibration Relay Lens (CRL) CU Focal Plane (CFP) CU design v1p: with internal pupil Intermediate Pupil Plane (IPP) Only if an intermediate pupil is needed before the focal plane

20. 27.01.2006, PM4.20 A trace mask (right) is used to trace possible distortions of the spectra (left). Trace Mask

21. 27.01.2006, PM4.21 Flatfield Calibration: spatially uniform to within 10% over full FOV spatially uniform to within 1% over any subfield of 1/10 FOV spectral uniformity 30% (blackbody) SNR > 100 in 10 sec exposures spatial and spectral stability 1 % over 24 hours Wavelength Calibration: nominal wavelength range : 0.465 – 0.930 m accuracy: 1/10 pixel (system level) spectral line lamps : TBD typical exposure time : 10 sec with SNR ~ 20 Image Quality Calibration: measuring PSF at any wavelength over whole FOV with 1% accuracy 3 PSFs for each slice PSF pinhole at any position over FOV pinhole stability: 1/10 spaxel ( 11.6 m WFM / 1.5 m NFM ) Requirements details for details see: CU Technical Specifications Version: 2.3 from: 26/04/2005 VLT-SPE-MUS-14670-0022