1. PFIS Camera & Collimator Conceptual Design
March 18, 2003
J. Alan Schier

2. General Layout 1

3. General Layout 2

4. Some Driving Requirements
Temperature Range: -5 to 20 ºC operating
-20 to 40 °C survival
Stresses: < 50 psi in crystalline elements, operating
Alignment Tolerances: General: 75 µm, 2 arcseconds
Tightest: 50 µm, 1 arcsecond

5. Salient Design Features 1
Fluid Coupled Multiplets
Use of NaCl and Sol-Gel Coatings
Collimator in Three Sections
Passive Thermal Compensation

6. Salient Design Features 2
Primary Materials:
Aluminum Alloy Structure
Delrin Thermal Compensators & Optics Seats
Stainless Steel Focus Flexures & Fasteners
1/4-80 Adjustment Screws
Cargille LL5610 Coupling Fluid
Sylgard 184 Bonding Compound
Polyurethane Bladders

7. Quantitative Results 1 Element Stresses: < 50 psi Operating
< psi Survival
< psi 20 ºC Step
Masses:
Collimator: kg Structure kg Optics
Camera: 19.2 kg Structure kg Optics

8. Quantitative Results 2 Structural Deflections: < 15 µm
< 15 arcseconds
Optical Element Motion Due to Gravity:
< 16 µm axial
< 1 µ radial
Optical Element Motion Due to Hydrostatics:
< 17.5 µm axial
< 36 arcseconds

9. Element Deflection Details

10. Thermal Behavior
Internal Conduction Much Faster Than Transfer to Environment For All Components (Minutes vs. Hours)
Internal Gradients Are Small
Structural Time Constants to Environment Similar (Hours)
Structure Equilibrates Evenly
Time Constants for Optics Can Be Longer Than for Structure (3:1)
Optics Lag Structure (stresses still OK).

11. Mounting Arrangements

12. Focus Suspension

13. Focus Mechanism

14. Alignment: Optics in Cell 1
Cell on A Spindle

15. Alignment: Optics in Cell 2
Place First Element

16. Alignment: Optics in Cell 3
Place Second Element

17. Alignment: As-Built Cell Dimensions
Measure Cell with Microscope

18. Alignment: Cells Into Barrels 1
Collimator Barrel First Element on Spindle

19. Alignment: Cells Into Barrel 2
Collimator Second Element

20. Alignment: Collimator Subsections 1
Alignment Telescope to Collimator Barrel

21. Alignment: Collimator Subsections 2
Collimator Last Group to Alignment Telescope

22. Alignment: Collimator Subsections 3
Collimator Front Group to Alignment Telescope

23. Alignment: Collimator Subsections 4
To se the spacing of the last group, pinhole placed at telescope focus and...
Last group spacing set in double pass by monitoring returned pinhole image
Or with shear plate (>80 m wavefront radius of curvature sensitivity) Can be done with alignment telescope in place.

24. NaCl Issues Must be kept in dry environment Must avoid contamination
Dehumidified assembly room.
Must avoid contamination
Handled by edges with dust-free gloves.
Placed in cell with lifting fixture.
Assembly area is pseudo-cleanroom.
No liquids allowed in the area.

25. Sol-Gel Issues 1 Must avoid contamination
Handled by edges with dust-free gloves.
Placed in cell with lifting fixture.
Assembly area is pseudo-cleanroom.
No liquids allowed in the area.

26. Sol-Gel Issues 2 No contact measurements possible
As-built measurements with measuring microscope and video camera.
Spacings set with reference to datum surface on cells.