1. Oct 10, 2002SSWG1 Prime Focus Imaging Spectrograph Status Engineering Status Optics Mechanical Control System Management Budget Schedule

2. Oct 10, 2002SSWG2 Optics Design Updates Slit Throughput VPH Grating Complement Optomechanical Concerns Procurement plan

3. Oct 10, 2002SSWG3 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 Fused silica -> fused quartz in common collimator beam (for NIR) Camera configuration update Details

4. Oct 10, 2002SSWG4 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

5. Oct 10, 2002SSWG5 Spectral Resolution vs. Throughput

6. Oct 10, 2002SSWG6 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 gratings- magazine designed for swapout

7. Oct 10, 2002SSWG7 VPH tradeoff

8. Oct 10, 2002SSWG8 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

9. Oct 10, 2002SSWG9 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 CaF 2 blank costs may be increased –investigating VPH and etalon effects Details

10. Oct 10, 2002SSWG10 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

11. Oct 10, 2002SSWG11 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

12. Oct 10, 2002SSWG12 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

13. Oct 10, 2002SSWG13 Management Budget re-projection Schedule

14. Oct 10, 2002SSWG14 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 263958

15. Oct 10, 2002SSWG15 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

16. Oct 10, 2002SSWG16 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: 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)

17. Oct 10, 2002SSWG17 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

18. Oct 10, 2002SSWG18 Done!

19. Oct 10, 2002SSWG19 Optics Details

20. Oct 10, 2002SSWG20 NIR Beam

21. Oct 10, 2002SSWG21 Optics Configuration

22. Oct 10, 2002SSWG22 Camera triplet modification –CaF 2 -> silica –“aplanatic” configuration reduced MAD on asphere focus singlet + triplet

23. Oct 10, 2002SSWG23 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 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

24. Oct 10, 2002SSWG24 Mechanical Details

25. Oct 10, 2002SSWG25 Completed Designs slitmask waveplates collimator assembly gratings camera articulation

26. Oct 10, 2002SSWG26 Camera Articulation bearing gearbox/ motor pinion pneumatic detent, 0.5 deg spacing camera tube

27. Oct 10, 2002SSWG27 Camera Support

28. Oct 10, 2002SSWG28 Grating Mechanism pneumatic insertor grating rotator linear stage selector 6 gratings

29. Oct 10, 2002SSWG29 Collimator Assembly guider feet slitmask magazine waveplates main collimator group

30. Oct 10, 2002SSWG30 Waveplate Mechanism blank halfwave plate quarterwave plate

31. Oct 10, 2002SSWG31 Slitmask Mechanism - 1 linear stage selector magazine pneumatic insertor mask in position

32. Oct 10, 2002SSWG32 Slitmask Mechanism - 2 pneumatic extractor

33. Oct 10, 2002SSWG33 Control System Details

34. Oct 10, 2002SSWG34 Generic Mechanism Test Hardware –candidate motor, encoders, hall sensors, pneumatic –motor drivers –signal conditioner –PXI motor card, I/O card

35. Oct 10, 2002SSWG35 LabView Hierarchical VI’s Commandable from scripts

36. Oct 10, 2002SSWG36 Management Details

37. Oct 10, 2002SSWG37 Detail CDR Schedule