Prime Focus Imaging Spectrograph

Transcription

1 Engineering Status Optics Mechanical Control System Management Budget Schedule Prime Focus Imaging Spectrograph Status Oct 10, 2002 SSWG 1 Optics Design Updates Slit Throughput VPH Grating Complement Optomechanical Concerns Procurement plan Oct 10, 2002 SSWG 2

2 Optics Design Updated camera and collimator to final indices ~ 2 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 7 throughput Resolution at a given grating angle reduced to 7. Found can increase maximum articulation of camera to 100 deg, increases max resolution 2: R = 5500 at 50 deg tilt, 1.25 arcsec slit Oct 10, 2002 SSWG 4

3 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

4 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

5 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 Details 4 CaF 2 blank costs may be increased investigating VPH and etalon effects Oct 10, 2002 SSWG 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

6 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) Articulate to 100 deg Details 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

7 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 Oct 10, 2002 SSWG 14

8 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 (5) 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: CaF 2 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

9 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

10 Optics Details Oct 10, 2002 SSWG 19 NIR Beam Articulation Axis Fold/ Dichroic Fold 20+/- 20 mm NIR Beam (future) Visible Camera Pupil Pupil Focus Collimator Articulation Axis Focal plane Oct 10, 2002 SSWG 20

11 Filters Focus (Polarizing beamsplitter CCD Camera (Etalons) Optics Configuration Side View (Fabry-Perot) Collimator (Waveplates) Focal Plane CCD (Etalons) Fabry-Perot (Grating) Shutter VPH Spectroscopy (maximum articulation) Top View Oct 10, 2002 SSWG CCD 21 Camera triplet modification CaF 2 -> silica aplanatic configuration reduced MAD on asphere focus singlet + triplet Asphere MAD = 0.45mm Asphere MAD = 0.35 mm Silica CaF 2 NaCl Focus group NaCl Oct 10, 2002 SSWG 22

12 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 CaF 2 : 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

13 Completed Designs gratings slitmask collimator assembly camera articulation waveplates Oct 10, 2002 SSWG 25 Camera Articulation camera tube gearbox/ motor bearing pneumatic detent, 0.5 deg spacing pinion Oct 10, 2002 SSWG 26

14 Camera Support Oct 10, 2002 SSWG 27 pneumatic insertor Grating Mechanism 6 gratings linear stage selector grating rotator Oct 10, 2002 SSWG 28

15 Collimator Assembly main collimator group slitmask magazine guider feet waveplates Oct 10, 2002 SSWG 29 Waveplate Mechanism halfwave plate blank quarterwave plate Oct 10, 2002 SSWG 30

16 Slitmask Mechanism - 1 linear stage selector magazine mask in position pneumatic insertor Oct 10, 2002 SSWG 31 Slitmask Mechanism - 2 pneumatic extractor Oct 10, 2002 SSWG 32

17 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

18 LabView Hierarchical VI s Commandable from scripts Controller Stepper Pneumatic Initialize Port 1 On Port 1 Off Position 0 Enable Disable Controller Data Initialized Enabled Stepper Data Home Pneumatics Data Index Port 1 Moving Port Set 2 On Position Kill Port 2 Off Unkill Killed Port 2 Fwd Limit Homed Fwd Limit Rev Limit Adjust Position Home Indexed Steps Rev Limit 0 Index Quadrature Counts 0 Cable Sensor 0 Tab Control Oct 10, 2002 SSWG 35 Management Details Oct 10, 2002 SSWG 36

19 ID Task Name 1 Prime Focus Imaging Spectrograph 17 Phase 3 - Critical Design 18 System Review 19 Critical Optical Design 20 Image Motion Analysis 21 Throughput Resolution Analysis 22 Mounting Sensitivity Analysis 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 36 Fold Mirror Specification 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 Critical Mechanical Design 67 PFIS Structure 73 Critical Wave Plate Design 78 Critical Slitmask Design 83 Mount Foot for Guider 87 Critical Grating Design 93 Critical Articulation Design 99 Critical Filter Design 105 Focus Camera 110 Critical Etalon Design 112 Camera Tubes 115 Focus (Collimator) Design 118 Critical Shutter Design 121 Critical Polarizer Design 125 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 10 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter 1st Quarter D J F M A M J J A S O N D J F M Detail CDR Schedule 10 s 10 s 10 3 wks 10 3 wks 10 3 wks wks 10 5 days days % 62% 88% 57% 78% 65% 54% 52% 86% 54% days days days 26% 38% days? days 2.22 days 10 days Oct 10, 2002 SSWG 37 1 day