preliminary design review

Preliminary Design Review

Katie SchwertzOptics 523April 3, 2009

Overview

Mounting an illumination lens and test plate into a single cell Lens diameters = 16” Material = Fused Silica

Test Plate

Illumination Lens

Requirements Review

Test Plate Concave surface: RMS slope error < 10 nm/cm (0.1 urad)

Alignment of lenses 100 um position 1 mrad angle 10 mm nominal separation (100 um tolerance)

Adjustment of cell 0.2 urad angular sensitivity 0.15um translation sensitivity (along axis) Coarse and fine adjustments

Interface Access points needed at 3 points around cell for a feeler gauge measurement Test plate will be 5 mm away from next surface Cell will sit within another cell on rollerballs in kinematic grooves

Interface

12 sets of kinematic grooves around diameter

Piezoelectric stages will drive this cell from underneath (Z-direction) to obtain fine axial adjustments required

Design Concept

Mirror adjuster/micrometer

6 axial flexures

3 counterweight supports

access points (3)

Slope analysis: 6 point flexure

RMS Slope Error = 1.35 nm/cm

Flexure Properties

Vukabratovich, pg. 145-146

Flexure Material: CRES 17-4

Design Concept

Mirror adjuster/micrometer

6 axial flexures

3 counterweight supports

access points (3)

Counterweight

Vukabratovich, pg 297

Flexure Positioning (1)

• Apply moment to each flexure attachment point

•See how much slope error is imparted onto the lens with a given angle

Flexure Positioning (2)

• Adjust angle of flexures to determine optimal angle to mount flexures

Action Items

Finish Solidworks models of interfaces and counterweights

Determine moment tolerance Determine optimal angle of flexures Determine thickness/stiffness of cell needed

Appendix – Lens Drawings

Appendix – Lens Drawings