1. 1 Discussion for basic options — engineering video conference July 12, 2006 Outline Water pool — advantages — issues, problems, engineering options Aquarium — advantages — issues, problems, engineering options Summery (after discussion)

2. 2 Tunnel ground ~7m ~5m Design special jig for lifting Typical Concept design for Water Pool ： Central Detector (CD) in the water Engineering Issues: 1). Lifting system — crane 2). Positioning: - How to keep positioning precision < 10 mm? - How to establish the Guide rail or Guide block for good position? - Is it possible to adjust underwater? 3). Top tracker system — open for CD move in and lift out? - 2 options for designs Option for deploy the Central Detector : - place 4 CD in a line? - place 4 CD in 2 pairs?

3. 3 To use Crane for lifting, relevant engineering issues: 1). Stronger Cylinder: Rib + flange +wall ? 100T load supported by its structure. 2). Cylinder with Nacelle? It bear load separately. 3). Special tools for lifting: jig, sling, hooks,… 4). Calibration Box removable? not conflict with lifting tool? 5). Possibility in water? mounting? positioning? other operations? … Previous drawings

4. 4 Water pool with plane roof （ 4 CD in 2 pairs ） The gap between veto-detector support structures and top covers of the pool should be wide enough for calibration equipment Muon tracker (RPC? Scint.? LS?...) will be mounted in the roof.

5. 5 4 Central Detectors be deployed in water pool (17m x 17m x 9.5m)

6. 6 Opening by Spools with counter weight and servo motors? Roof structure should be strong enough with high rigidity. Inside Veto systems no any shift during opening and closing

7. 7 Is it possible for roof to keep in such position? Concerned Factors: Weight: > 30 Tons estimated, depending on RPC? LS? Scint.?... Deformation:? Due to structure: big and thinner (17m x 8.5m); Fixations for veto inside structure, cabals, gas pipes…? Sychro-precision: controlled by motor driving?

8. 8 Support hinges and trunnions fixed on the edges of water pool

9. 9 10m hall access Water pool with slide roof 2 layers of roof with stronger structure; Supported and slide on 2 pairs rails on 2 sides of water pool; Need additional height of hall; detector area increase accordingly.

10. 10 veto detectors mounted on the underside of the roof ？ Veto detectors mounted on the upside of the roof

11. 11 water muon tracker rock a conceptual design dam water plug water plug Previous Aquarium design

12. 12 Water Cerenkov Outer Veto

13. 13 E645 Veto shield Note: achieved ~10 -5 inefficiency

14. 14 How To Build It?

15. 15 Water dam Crane (20 tons?) Top Veto detectors layer Light sealing layer water plug Access plug Steel tube The lateral and bottom faces will be covered by : PMTs?,or Water tanks, or PLS? Aquarium option with Bob’s considerations

16. 16 Rails on the support beams Space for calibration work

17. 17 Weight for water plug: (roughly calculate) Structure: 14 tons, volume of water: 112 m3 total weight: 112+14 = 126 tons Weight for access plug: structure: 1.5 tons; volume of water: 5 tons; total weight: 1.5+5 = 6.5 tons. Top veto detectors: without any movement. Additional Space: Water plug moving away; Transportation: Hilman roller is better than lowboy for position Central Detector

18. 18 Steel Tube: diameter 9 m; length: 17 m; volume: 1060 m3; weight: 76 tons Support column: 0.61 x 18 = 11 tons; Support I beams: 2.4 x 3 = 7.2 ton

19. 19 water tunnel Conceptual Design of Aquarium

20. 20 Consideration about buoyancy: If tube totally in the water: buoyancy would be 1060 tons; It is possible to modify the tube structure to avoid buoyancy. 1060 tons of buoyancy Modify tube structure to avoid buoyancy

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23. 23 Aquarium Option Summary - Issues Engineering Issues –Tube structural design buoyancy forces non-uniform external hydro pressure detector support (100T per detector) field construction –Plug design Internal hydro pressure Movement (roll out how?, where does it go in the hall?) –Materials (minimize addition to background radiation) Low radiation steel and weld rod? Or low radiation concrete?? –Central detector movement on Hillmans or trailer? If Hillmans/train rails, need design study on transition from trailer to plates/rails

24. 24 Aquarium Option - Pros & Cons Pros –Dry detector Accessability for maintenance and repair, calibration –No lifting No additional structure to deal with lifting loads No BIG crane in hall Less risk of jostling of internal elements (acrylic vessels, ports) –Simple placement/alignment Easy survey – direct line of sight Hard stops possible? –No deep (below tunnel level) pit required –Less water to fill/drain filter?

25. 25 Aquarium Option - Pros & Cons Cons –Higher civil construction costs bigger hall required? Water tight dam tube structure fab and installation –Higher background radiation circulating air/radon/dust surrounding steel?