Slicer development Eric Prieto LAM

ESA PROTOTYPE

In reality November 15 & 16, 2005 Eric Prieto -LAM

Telescope pupil images after reflection on the slicer Slicer Stack Only 10 active slices 20 dummies Spherical slices (0.9mm thick, 28 mm long) 30 slices stack Optical bonding assembly All in Zerodur Silver protected coating Telescope pupil images after reflection on the slicer November 15 & 16, 2005 Eric Prieto -LAM

Slit images after reflection on the pupil mirrors 5 pupil mirrors (2.7mm width) Spherical active surface Silver protected coating Optical bonding INVAR structure Slit images after reflection on the pupil mirrors November 15 & 16, 2005 Eric Prieto -LAM

Prototype performances Thermal straps Thermometers END 03 November 15 & 16, 2005 Eric Prieto -LAM

conclusions Glass manufacturing in spécification: OK Optical performance: OK Cryogenic operation: OK Vibration survival of the optical assembly: OK Opto-mechanical mount: FAIL No clear specification for vibration at the beginning of the study Structure not design for such load A posteriori simulations demonstrate the stress > 10 MPa in zerodur To be prototype early in the development BUT THIS A PROBLEM ALREADY SOLVED IN OTHER INSTRUMENT ZERODUR OPTICS ARE CLASSICAL FOR SPACE APPLICATION November 15 & 16, 2005 Eric Prieto -LAM

Big Numbers LAM current baseline Slice .9mm x 30mm (.5mm in prototyping) Slice positioning <10’’ (15µm center of curvature) Ra: 1nm Surface quality: 5nm rms Cracks < 5µm (specification for SNAP slicer) Two vendors (SESO – WINLIGHT) Manufacturing cost for space delivering fly unit: 20k€/slice Manufacturing cost for 30 slicers for ground application: 2k€ /slice For SNAP very rough estimate: 5-10 k€ / slice LAM current baseline November 15 & 16, 2005 Eric Prieto -LAM

Slicer around the world

DURHAM GNIRS-IFU Based on diamond turned techniques Big numbers presented during meetings: Ra: 8nm WFE: <50 nm rms Edge ? Slice orientation: <1” Monolithic Long lead learning process to know how manufacture No industrial Vendor One Lab for manufacturing: LFM (difficult) Second lab in the learning curve: Durham November 15 & 16, 2005 Eric Prieto -LAM

We are hungry to know results CRAL Long prototyping work on Glass Slicer: good results But costly and very long lead item for 24 units: Trade manufacturing process Metallic approach Some vendors contacted and prototypes We are hungry to know results November 15 & 16, 2005 Eric Prieto -LAM

Oxford SPIFFI Heritage : SWIFT Flat slices 30-40 slices Glass slices Vendor: WINLIGTH (same than the SNAP demonstrator) Chosen as well establish technology November 15 & 16, 2005 Eric Prieto -LAM

Opticon – JRA 5 European effort Axed to replication for Cost Manufacturing process Metallic mandrels Roughness and WFE under studies Result end 07 November 15 & 16, 2005 Eric Prieto -LAM

LAM Axis Optimisation of the designs: Concentric slicer (SPIE 04 + SNAP concept) Fan shape (Proposal IFU/NIRSPEC – SPIE 06 + …) Manufacturing cost reduction slicer design for MIFU: SPIE 06 Prototyping SNAP IFU (demonstrator – SPIE 06 …) Improving coupling ifu and instrument: Interaction between IFU design and instrument design Trying to have an overall instrument simplification (concentric slicer) Rational manufacturing approach Survey of other manufacturing approach and performance associated November 15 & 16, 2005 Eric Prieto -LAM

SNAP ROADMAP Demonstrator to validate: the optical performances Existence of one manufacturing process Trade the manufacturing techniques versus: Performance Opto-mechnical interfaces Cost Prototype the relevant point for the selected approach: Opto-mechnical interface for the glass approach Manufacturing for SiC approach (full SiC instrument ?) Quality for aluminum approach Next months study to propose the next step in prototyping for SNAP November 15 & 16, 2005 Eric Prieto -LAM