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

General Layout 1

General Layout 2

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

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

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

Quantitative Results 1 Element Stresses: < 50 psi Operating < 100 psi Survival < 300 psi 20 ºC Step Masses: Collimator: 22.4 kg Structure + 16.8 kg Optics Camera: 19.2 kg Structure + 30.9 kg Optics

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

Element Deflection Details

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).

Mounting Arrangements

Focus Suspension

Focus Mechanism

Alignment: Optics in Cell 1 Cell on A Spindle

Alignment: Optics in Cell 2 Place First Element

Alignment: Optics in Cell 3 Place Second Element

Alignment: As-Built Cell Dimensions Measure Cell with Microscope

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

Alignment: Cells Into Barrel 2 Collimator Second Element

Alignment: Collimator Subsections 1 Alignment Telescope to Collimator Barrel

Alignment: Collimator Subsections 2 Collimator Last Group to Alignment Telescope

Alignment: Collimator Subsections 3 Collimator Front Group to Alignment Telescope

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.

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.

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.

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.