Preliminary Design Review Katie Schwertz Optics 523 April 3, 2009
Overview Mounting an illumination lens and test plate into a single cell Lens diameters = 16” Material = Fused Silica Illumination Lens Test Plate
Requirements Review Test Plate Alignment of lenses Adjustment of cell 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 3 counterweight supports 6 axial flexures Mirror adjuster/micrometer access points (3)
Slope analysis: 6 point flexure RMS Slope Error = 1.35 nm/cm
Flexure Properties Flexure Material: CRES 17-4 Vukabratovich, pg. 145-146 Flexure Material: CRES 17-4
Design Concept 3 counterweight supports 6 axial flexures Mirror adjuster/micrometer 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