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Prime Focus Imaging Spectrograph Status • Engineering Status Optics Mechanical Control System • Management Budget Schedule Oct 10, 2002 SSWG 1 Optics • • • • • • Design Updates Slit Throughput VPH Grating Complement Optomechanical Concerns Procurement plan Oct 10, 2002 SSWG 2 Optics Design • Updated camera and collimator to final indices – ~ 20% image quality degradation; • decrease manufacturing margin? • relieve spec? • Completed thermal design. Focus in camera • Updated pupil placement and fold mirror position for maximum NIR collimated beam Details • Fused silica -> fused quartz in common collimator beam (for NIR) Details • Camera configuration update Details Oct 10, 2002 SSWG 3 Slit Throughput • PDR: “max resolution 6250 overstated”. Used median seeing 0.9 arcsec, not telescope image • Model using seeing degraded to 37 deg ZD, actual SAC, actual PFIS model – In median seeing, a 1.25 arcsec slit will give 70% throughput – Resolution at a given grating angle reduced to 70%. • Found can increase maximum articulation of camera to 100 deg, increases max resolution 20%: R = 5500 at 50 deg tilt, 1.25 arcsec slit Oct 10, 2002 SSWG 4 Spectral Resolution vs. Throughput Oct 10, 2002 SSWG 5 VPH Grating Complement • VPH procurement in next 6 months, tradeoff required: UV efficiency vs high resolution efficiency • Suggest: efficiency in UV for highest and lowest density gratings; efficiency at high resolution for other three • Note that SALT can easily add VPH gratingsmagazine designed for swapout Oct 10, 2002 SSWG 6 VPH tradeoff Oct 10, 2002 SSWG 7 Optomechanical • Largest PDR risk: optics, especially optomechanical, underbudgeted • Award subcontract for optomechanical to J. Alan Schier – optomechanics for Keck ESI, DEIMOS – comfortable with fluid coupling, salt, solgel • Tasks – mounting tolerancing – design, fabricate lens holders – assemble lens groups Oct 10, 2002 SSWG 8 Current concerns • Coating strategy – baseline: solgel on interior surfaces; hard elsewhere – cost poorly defined • Stress birefringence in collimator potentially degrading polarimetric efficiency – blanks: NaCl possible problem; lack of data – 4 CaF2 blank costs may be increased – investigating VPH and etalon effects Oct 10, 2002 SSWG Details 9 Optics procurement • before CDR – – – – third etalon (before year’s end to get good price) fold flat/ coating camera/ collimator blanks grating blanks • just after CDR – camera/ collimator figuring – waveplates, beamsplitter – VPH gratings Oct 10, 2002 SSWG 10 Structure/ Mechanisms • Structure – guide mount interface designed – collimator assembly • Mechanisms designed – – – – waveplate slitmask grating. 6 grating complement camera articulation. • Will do full articulation in < 20 sec (enable PFIS imaging mode as slitmask setup) Details • Articulate to 100 deg Oct 10, 2002 SSWG 11 Control System • Hardware – generic mechanism test bed operational: use for LabView learning curve, answering operational questions for mechanism designs – wiring architecture; box placement; cable harness • Software – actually operating hardware – prototype client / server, scripting developed – consistent with telescope architecture Details Oct 10, 2002 SSWG 12 Management • Budget re-projection • Schedule Oct 10, 2002 SSWG 13 Cost-to-Completion Deltas Base Dollars PDR ’02 Q1 ’02 Q2 ’02 Q3 UW $2,426,501 $2,616,194 $2,675,390 $2,814,391 Tot $3,645,947 $3,835,640 $3,929,229 $4,068,574 Delta $189,693 $93,589 $139,345 % Cont 26 39 58 Oct 10, 2002 SSWG 14 Chief Deltas • Q1-2 ($94K) – CDR electrical engineering underestimate $15K – SAAO Cryotiger, etc $25K – US$ slowed inflation $50K • Q2-2 ($139K) – Drafting subcontract underestimate: $97K - $50K $20K = $27K. Control mech design schedule risk. – Optomechanical subcontract: $220K - $50K - $20K = $150K. Control optics technical/ schedule risk; biggest PDR budget deficiency Oct 10, 2002 SSWG 15 Prognosis • Contingency use (58%) somewhat above expected (50%) at this point, but still on track. Remaining deltas will be much better known at CDR: • Capital purchases. Preliminary RFQ’s on largest – likely increases: CaF2 blanks; coatings – likely savings: mechanisms/controls; lens fabrication; slitmask mill • Schedule. Remaining contingency would cover 8 months slip. • When do we start spending contingency? At current rate, Q1 ’04; at rate which would spend cap, Q4 ’03 (well after CDR) Oct 10, 2002 SSWG 16 Schedule • Milestone: CDR 17 Mar, 2002 – slipped 2 months from PDR; mechanical design critical path – recover: drafting/ engineering subcontract help • Optical – optomechanical subcontract kickoff – procure blanks, issue pre-CDR RFQs • Mechanical: 4 most complex mechanisms completed • Control System: in progress – hardware wiring diagram – Labview design well under way • Detail fabrication/ testing schedule in work this month Details Oct 10, 2002 SSWG 17 Done! Oct 10, 2002 SSWG 18 Optics Details Oct 10, 2002 SSWG 19 NIR Beam 20+/- 20 mm NIR Beam (future) Fold/ Dichroic Fold Articulation Axis Articulation Pupil Axis Focus Visible Camera Pupil Collimator Focal plane Oct 10, 2002 SSWG 20 Filters CCD Focus (Polarizing beamsplitter Camera (Etalons) Collimator Side View (Fabry-Perot) Optics Configuration (Waveplates) Focal Plane (Etalons) CCD Shutter Fabry-Perot (Grating) VPH Spectroscopy (maximum articulation) Top View Oct 10, 2002 SSWG CCD 21 Camera CaF2 Asphere MAD = 0.45mm • triplet modification – CaF2 -> silica – “aplanatic” configuration • reduced MAD on asphere • focus singlet + triplet NaCl Silica Asphere MAD = 0.35 mm Focus group NaCl Oct 10, 2002 SSWG 22 Birefringence Budget • Unusual SALT configuration puts large glass path (17 cm!) between waveplate and beamsplitter • Stress birefringence at 45° to polarimetric axis causes depolarization d ~ (π w)2 (w = biref in waves). d < 2% => w <~ 1/20 wave, biref/cm <~ 2-10nm/cm • Have birefringence budget for – – – – – – Fused silica, quartz: 1 -5 nm/cm CaF2: 1-2 available at extra cost NaCl: unknown. sample now being measured Folding flat LLNL coating VPH grating Etalon Oct 10, 2002 SSWG 23 Mechanical Details Oct 10, 2002 SSWG 24 Completed Designs gratings slitmask collimator assembly camera articulation Oct 10, 2002 waveplates SSWG 25 Camera Articulation camera tube gearbox/ motor pinion bearing Oct 10, 2002 pneumatic detent, 0.5 deg spacing SSWG 26 Camera Support Oct 10, 2002 SSWG 27 Grating Mechanism pneumatic insertor linear stage selector 6 gratings grating rotator Oct 10, 2002 SSWG 28 Collimator Assembly main collimator group slitmask magazine guider feet Oct 10, 2002 waveplates SSWG 29 Waveplate Mechanism halfwave plate quarterwave plate blank Oct 10, 2002 SSWG 30 Slitmask Mechanism - 1 linear stage selector magazine pneumatic insertor mask in position Oct 10, 2002 SSWG 31 Slitmask Mechanism - 2 pneumatic extractor Oct 10, 2002 SSWG 32 Control System Details Oct 10, 2002 SSWG 33 Generic Mechanism • Test Hardware – candidate motor, encoders, hall sensors, pneumatic – motor drivers – signal conditioner – PXI motor card, I/O card Oct 10, 2002 SSWG 34 LabView • Hierarchical VI’s • Commandable from scripts Controller Controller Controller Stepper Stepper Pneumatic Pneumatic Pneumatic Stepper Data Home Initialize Controller Data Port 1 On Position Port 1 Off Index Initialized 0 Enable Pneumatics Data Disable Port 1 Moving Enabled Port 2 On Set Position Kill Port 2 Fwd Limit Port 2 Off Unkill Killed Homed Fwd Limit Rev Limit Adjust Position Home Indexed Rev Limit Steps 0 Index Quadrature Counts 0 Cable Sensor 0 Tab Tab Control Control Oct 10, 2002 SSWG 35 Management Details Oct 10, 2002 SSWG 36 ID Task Name 1 Prime Focus Imaging Spectrograph 17 Phase 3 - Critical Design 1st Quarter J D F M 2nd Quarter A M J 3rd Quarter J A 4th Quarter O S D 1st Quarter J F M 57% 18 System Review 19 Critical Optical Design 20 Image Motion Analysis 21 Throughput Resolution Analysis s Detail CDR Schedule 22 Mounting Sensitivity Analysis s 100% 23 Final Collimator Design 24 Final Camera Redesign 25 Preliminary Thermal Analysis / Design 26 Final Thermal Analysis / Design 27 Prepare SPIE paper 28 Update Optical Design Document 29 RFP For Optomechnaical Design 100% 36 Fold Mirror Specification 100% 38 RFP For Camera / Collameter Optical Design 45 Grating Substrates Specification 48 Slit Mask Factory 51 Waveplates 54 Beam Splitters 57 Slit Viewers 60 VPH Grating 62 SR Gratings 64 Color Filters 66 N 100% 100% 78% 100% 3 wks 100% 3 wks 100% 3 wks 100% 19.4 wks 100% 5 days 100% 6.15 days 100% 65% 0% 0% 0% 0% 0% 0% 0% 0% Critical Mechanical Design 54% 67 PFIS Structure 73 Critical Wave Plate Design 78 Critical Slitmask Design 81% 83 Mount Foot for Guider 62% 87 Critical Grating Design 93 Critical Articulation Design 99 Critical Filter Design 105 Focus Camera 0% 110 Critical Etalon Design 0% 112 Camera Tubes 115 Focus (Collimator) Design 0% 118 Critical Shutter Design 0% 121 Critical Polarizer Design 125 52% 86% 88% 54% 0% 0% 0% Critical Control System Design 126 Generic Mechanism 132 Client / Server Design 133 User Interface Design 134 User Interface prototype 135 Wiring Diagram and Grounding & Switching Plan 145 Scripting Lannguage 148 Slitmask 151 Wave Plate 154 Other Mechanisms 162 Interlock Design Document (Whole) 163 Final Mechanism Control Design (Whole) 164 Power and Thermal Budget 165 Interface Control Documents 169 Prepare CDR Package 170 Critical Design Review Oct 10, 2002 30% 100% 11.63 days 80% 17.44 days 0% 17.44 days 0% 26% 38% 0% 10% 0% 11.5 days? 100% 5.56 days 2.22 days 0% 0% 0% 10 days SSWG 37 0% 1 day 0%