1. Slicer development
Eric Prieto
LAM

2. ESA PROTOTYPE

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

4. 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

5. 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

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

7. 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

8. 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

9. Slicer around the world

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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