1. DARK ENERGY CAMERA INSTALLATION AT CTIO For DES director review F. Munoz –CTIO -May 2011 1

2. Assembly Outline PRELIMINARY DECam Assembly – Working area at Blanco G-floor

3. Assembly Outline Preliminary : DECam Assembly -Development of a clear work-area in the G-Floor storage zone of 4M Building. -Far from Blanco Telescope observations -Clean & isolated area: 6X8m - 6m up. -For DECAM corrector integration – Cage assembly without don’t requires frames. -Light framing with walls: antidust/ESD/fire resistant. -Interference with hatch area : the structure is made from TWO independent frames: disassembly one allows pass-through for parallel duties (i.e Newfirm) - Lifting: Monorail hoist, 15 tons, Electric – 2 speeds bth trolley & hook, wireless. -Allows Full DECam cage integration and lifting / rotation test. -Rail Located at the mid-plane of the working area. - Span: 8m. Max Headroom: 6.3 m When completed, move Cage & cart to hatch area and lift to M-floor

4. Assembly Outline PRELIMINARY DECam Assembly – Full Working area at Blanco G-floor

5. Assembly Outline PRELIMINARY DECam Assembly – Once corrector is done, DECAM could remain in one small clean area, leaving the north side free for other duties

6. Assembly Outline Assembly includes: (From top to bottom) -Imager Dummy Weight with C5/SBIG cameras -Corrector - with C1/2/3/4 -Hexapod -Cage Strong-Backs -F/8 CW - Plus: Baffle, Light Upper CW Estimated/Tested weight to be lifted and balanced for commissioning W = 21,000 lbs Further elements beyond installation FCMA/DECAM imager/Electronics front end/ Covers/strong-backs will be removed New balance configuration 6

7. PREREQUISITES to be completed before DECAM installation: From DES -DECAM acceptance tests. -Ground LN2 systems installed, required feed wiring present. -DECAM Cage optical alignment fixture installation point. -Currently, the flat-lower surface of F/8 CW (Optical alignment phase “0”). From CTIO -M1 handling stuff (carts, tools) on C-floor. PFC cart on M-floor. -Existing PFC measures recorded, Turnbuckles Spares and fins thd-taps. -Cage Elements (fins) labeled/ Cage mechanical connections inspected. -MOSAIC –II removed (not NW task). -Strain Gauges installed at fins. (currently working on it). THEN  MOVE DECAM TO M-FLOOR & STOW 7 REQUIREMENTS

8. Tasks at NW M1 removal Existing PFC removal DECAM Cage installation Optical Alignment – Stress Tuning Auxiliary Stuff Removal M1 Re-installation GOALS -SAFELY REMOVE EXISTING PFC -DECAM INSTALLED WITHIN 1.0 [mm] Optical Axis Offset 0.1 [deg] TILT 8 OUTLINE

9. Tasks at NW - Blanco Offline  Stop observations. -F/8 Cell removal & stow at NW / remove both PF petals. -Dismantle existing PFC & Secondary rings/fins wiring. -Flip must be set at PRIME FOCUS position  mark L1 -Install existing PFC Lifting. -Optical Alignment Phase I: Install cross-hairs anchors at the serruriers trusses of the telescope. Along all operations: record mass & position of installed/removed items 9

10. Tasks at NW - F/8 Cell removal & stow at NW / remove PF petals 10

11. Tasks at NW Optical Alignment stuff installation – Phase I: Telescope Crosshairs anchors installation 11

12. Tasks at NW Work Platforms: -Installation work must be performed 55 ft/18m from M-floor level. - Personnel Safety as critical issue, M1 follows. -Blanco geometry (Horseshoe ) difficult useful external structure installation. -Inner scaffolding concept – FRAMES MODULES. - Design based on FNAL March tests. Technical Set – Up: -Main Frames modules : Light steel allows fast assembly. - Main frames anchors supports connected to telescope trusses. -Installation of anchors and frames to be performed at NW station. -Decks: Wood on steel frames units  Secure surface to work + fences. -Install decks at zenith : Telescope beams angles constrains connected frames from sliding. -Wood decking allows go thru levels with cage-fins connected. Safety : - During works, secure ALL EXISTING TOOLS to avoid fall down. - Reduce the duty time with boom lift extended. 12

13. Tasks at NW 13 Light module unit: 2 frames per deck required Telescope at NW with modules installed 2 story configuration

14. Tasks at NW Access: - Direct boom-lift access to mid-level. Fences will be present (not shown on this slide) 14

15. Tasks at NW Safety Issues: - Each frame to support up to 800 kgs. - Specific safety trainee to crew. -Main anchor points for safety harness (top level): Straps around secondary rings. 15

16. 16 Tasks at NW

17. Telescope Set-Out at NW AB46E Upright boom lift Electric, 16 m vertical/ 7,6 m horizontal - Access to work platforms (not use it for installation task). - Safety key equipment: Quick Rescue unit. 17

18. Tasks at NW M1 removal Existing PFC removal DECAM Cage installation Optical Alignment – Stress Tuning Auxiliary Stuff Removal M1 Re-installation GOALS -SAFELY REMOVE EXISTING PFC -DECAM INSTALLED WITHIN 1.0 [mm] Optical Axis Offset 0.1 [deg] TILT 18 OUTLINE

19. M1 Removal Remove NEWFIRM and M1 cell: -Lock & brace the telescope. -Remove & stow instrument on cart, M-floor SW, according observing schedule. Operation included on balance calculations. -Remove telescope Base Stairs to G-floor. -Remove Cass Cage & Baffle according to Blanco Shut-down Checklist. Carts available at C-floor level. -Optical Alignment– Phase II: Optical Axis definition tools tests: -Vertex Tool set-up/ K&E tool installation on M1 (tested on march shutdown). -Blanco Optical Parameters acquisition/Continue M1 removal. 19

20. M1 Removal 20

21. M1 Removal 21

22. M1 Removal 22

23. M1 Removal 23

24. Tasks at NW M1 removal Existing PFC removal DECAM Cage installation Optical Alignment – Stress Tuning Auxiliary Stuff Removal M1 Re-installation GOALS -SAFELY REMOVE EXISTING PFC -DECAM INSTALLED WITHIN 1.0 [mm] Optical Axis Offset 0.1 [deg] TILT 24 OUTLINE

25. Existing PFC removal - Plan Based on CTIO procedures tested @ FNAL-Lab A - Operate Cage with their fins connected. - Disconnect Cage at Bracket-pin joints level. - Use specific auxiliary tools for operations & adjustment. - Load Monitoring. - Requirements: Tag & label elements and positions /Lifting fixture with scale. -Tools design: Pin extractor: -To Push-out existing bracket/clevis pins connections safely. Fin-Holders (FHs): -Auxiliary arms to hold fins position. Adjustable length  Angular fin adjustment. 25

26. Existing PFC removal 26 -Crane Gaps

27. Existing PFC removal 27 -Plan: -Transfer load to crane. -Use tools & operate turnbuckles to release shear tension on the bracket pin. -Push Pin out, remove TB and clevis. -Use tools to keep fins in same relative position. -Sequence: Upper diagonal and center fins side, by opposite planes NW/SE/NE/SW then lower side  rotate as required and move cage down

28. 28 Existing PFC removal

29. Cage-fins configuration interference with telescope cell section - Lift M-floor elevator with skyjack to top level (1m from removed cell frame). - Reach every zone (lower center top). - Remove fins to elevator deck, then to M-f. - Continue moving cage down. - To be repeated backwards for DECam installation. Strain Gauges: - SG present on fins. Re-calibrate them for DECAM at this time. 29

30. Tasks at NW M1 removal Existing PFC removal DECAM Cage installation Optical Alignment – Stress Tuning Auxiliary Stuff Removal M1 Re-installation GOALS -SAFELY REMOVE EXISTING PFC -DECAM INSTALLED WITHIN 1.0 [mm] Optical Axis Offset 0.1 [deg] TILT 30 OUTLINE

31. DECAM INSTALLATION Plan Based on CTIO procedures tested @ FNAL-Lab A Preliminary - Move DECAM cart from stow to telescope - Move DECam to vertical, move out cart and place on floor. -Install DECAM rigging straps and connect them to load cell LF/crane. -Install fin holders to DECAM cage. -Lift cage few inches, to check horizontal alignment (within 1/4in) to ensure plumb. Use level tools, experience shows than DECAM must be lifted parallel to horizontal plane -Rigging and Adjust lifting fixture as required -Repeat Fins installation at Cell zone with new GE10 custom bushings Alignment issues: - Install Cage-alignment Optical Fixture at F8CW lower surface (phase 0) - Move up cage to upper rings, rotate and adjust as required to face fins/rings blocks - Install cross-hair at the removed cell position 31

32. DECAM INSTALLATION 32 FINS CONNECTION – MECHANICAL OVERVIEW -Over constrained mechanism. -Thin clearances/ Fine threads. -Currently installed and aligned at CTIO. -KPNO different configuration. Center fins parallel mechanism defines - A vertical midplane. - An horizontal midplane. - Four center fins properly aligned define the optical axis and the center point of rings: point to be achieved. Plan: -Lift cage roughly close to this references. -Connect lower fins and use them to reach this point.

33. DECAM INSTALLATION -Lifting fixture with load cell (20 tons): 33

34. DECAM INSTALLATION GOAL: Install DECAM cage at previous Prime Focus Point - Aligned to Blanco optical axis previously defined - 1.0 deg tilt. - Aligned to removed PFC horizontal plane centerpoint – 1.0 mm offset. - Both references recorded before (as requisite: Record existing Blanco PFC fins distances & positions AND optical axis definition steps). PLAN: -Define optical axis and rings horizontal mid-planes by laser tools. -Lift Cage as close as possible to this level and centerline. -Drive cage to main (recorded )references. -Use lower diagonal fins to lead cage to the defined center point position, then fix. -Adjustment :iterations, each vertical plane at time. -Confirm position by mean of optical tools (ground laser feedback). -Lock system  connect upper diagonal fins. -Iterate to connect center fins 34

35. DECAM INSTALLATION -Installation : Safety technical issues -Always avoid lead fins to compression. Torque induced moves cage to twist and to unexpected positions (use Strain Gauge ref.). -Non-linear behaviors for fins length adjustment. Iterations needed to avoid bind the 4-bars mechanism. -Crane load transfer under surveillance : never go below 5,000 lbs on crane before four lower fins connected. - Center fins to be under surveillance to avoid interferences with rings structure. No check this point may cause wrong alignment conditions due fake SG readouts. 35

36. DECAM INSTALLATION 36

37. DECAM INSTALLATION Installation Procedure : -Align lower fins. Load is on the crane. -Operate fin holders to install clevis and Turnbuckles on these fins. -Install Center fin yoke (free) between elements to keep design relative position. -Install Pin. -repeat for opposite side, then for 90deg plane. - Release crane. 37

38. DECAM INSTALLATION Installation Procedure : -Align lower fins. Load is on the crane. -Operate fin holders to install clevis and Turnbuckles on these fins. -Install Center fin yoke (free) between elements to keep design relative position. -Install Pin. -repeat for opposite side block, then for 90deg plane. -Release crane. Safe condition: perform this step soon in order to reduce the duty cycle of the crane. 38

39. DECAM INSTALLATION 39 Installation Procedure : ALIGNMENT -Adjust cage fins to coincide its midplane with rings midplane. Use recorded PFC measures as starting references. -Keep always tension  SG monitoring. -Iterations required, no-linear propagation at opposite sides.

40. Tasks at NW M1 removal Existing PFC removal DECAM Cage installation Optical Alignment – Stress Tuning Auxiliary Stuff Removal M1 Re-installation GOALS -SAFELY REMOVE EXISTING PFC -DECAM INSTALLED WITHIN 1.0 [mm] Optical Axis Offset 0.1 [deg] TILT 40 OUTLINE

41. DECAM INSTALLATION Installation Procedure : Optical alignment -While fins alignment is performed at rings level, Optical fixtures provides feedback for centering properly the cage in OA offset and tilt. - When cage is aligned within horizontal plane counterpoint and OA ranges, lock the system by connecting upper diagonal fins. TELESCOPE OA REF (GROUND) CAGE expected optical fixture crosshair 41

42. DECAM INSTALLATION Installation Procedure : Lock the system – Center fin installation - Connect upper diagonal fins as same as lower side procedures. - Now the system is over-constrained, no more alignment allowed. Adjust turnbuckles now will imply change the stress configurations at fins but no movements. As center strut pin is at mid-plane (requested condition), center fin parallel- mechanism triangle could be installed beating over constrains conditions 42

43. DECAM INSTALLATION -Installation Procedure : Complete installation and Stress tuning - At one block, Disconnect lower side pin, move diagonal fin out, install center fin yoke, align bores and re-install the pin. -Stress on fins are random, run stress-tuning operation - Algorithm Based on strain gauges readouts. - In order to set all fins to equalized tension. - Apply preload after iterations (offset to calculated stress). 43

44. DECAM INSTALLATION -Installation Procedure : DECAM aligned & installed 44

45. Telescope Set-Out at NW M1 Removal (NEWFIRM) Existing PFC Removal DECAM Cage installation Optical Alignment – Stress Tuning Stuff Removal M1 Re-installation – (ISPI) GOALS -SAFELY REMOVE EXISTING PFC -DECAM INSTALLED WITHIN 1.0 [mm] OAO 0.1 [deg] TILT 45 OUTLINE

46. DECAM INSTALLATION Installation - Last tasks, balance. -Remove fins tools and stuff from area. -Remove DECAM strong-backs to M-floor at the moment. -Remove platforms decks and frames at Zenith as required, using boom lift. -Prepare M1 to go back to telescope. -Align on cell and Re - install unit. - Set-up items to ISPI, Re balance Blanco with new CW – Cass Cage weight ring. 46

47. Telescope Set-Out at NW M1 Removal (NEWFIRM) Existing PFC Removal DECAM Cage installation Optical Alignment – Stress Tuning Scaffolding & Stuff Removal M1 Re-installation – (ISPI) GOALS -SAFELY REMOVE EXISTING PFC -DECAM INSTALLED WITHIN 1.0 [mm] OAO 0.1 [deg] TILT 47 TELESCOPE TO COMISSIONING