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