1. MEA Machine and Experiment Assembly Norbert Meyners, MEA 12. July 2007ILC IRENG07 WG-A1 LDC Engineering Design (Status) Introduction General Design Detector opening/End Cap Yoke Split or not Surface Assembly Underground Cavern Size Platform Conclusion

2. MEA Machine and Experiment Assembly Norbert Meyners, MEA 2 ILC IRENG07 WG-A 12. July 2007 Base The LDC concept is evolved from the TESLA detector concept. Picture from “Mechanical Concept of the TESLA Detector” (LC-DET-2001-045)

3. MEA Machine and Experiment Assembly Norbert Meyners, MEA 3 ILC IRENG07 WG-A 12. July 2007 Now H. Videau, C. Clerc, M. Anduze, LLR; M. Jore, LAL; K. Sinram, DESY; started to work on the Engineering Model (all part time) Several „small“ changes have happened over the years. Several question came up. Several items are under discussion. (See Videau’s talk: “Toward an LDC engineering model” LDC meeting, Paris May 4; 2007)

4. MEA Machine and Experiment Assembly Norbert Meyners, MEA 4 ILC IRENG07 WG-A 12. July 2007 General Design End Cap HCAL made of magnetic iron to serve as field forming nose (to improve the field quality in the central tracker)  Shorter Detector  High force Q: Fixture? LumiCAL enlarged to overlap with the end cap calorimeter Q: Support? Q: Access to Vertex detector? Central Barrel split in three rings for CMS style surface assembly

5. MEA Machine and Experiment Assembly Norbert Meyners, MEA 5 ILC IRENG07 WG-A 12. July 2007 Assumptions Surface assembly: in pure CMS style Main Solenoid discharged during the move: Charge/Discharge Time:~4 hours (CMS) Push/Pull Scenario: ~30 days running or maintenance 3-4 days detector exchange  Not only “fast” change over  ”Fast“ maintenance too! Vacuum: Flange and ion pump behind the LumiCAL LumiCAL Support With spokes between TPC and ECAL Central Beam Pipe Support By the reinforced inner tube of the TPC  Possible? or by the LumiCAL support  Stiff structure Vertex Detector maintenance Once a year

6. MEA Machine and Experiment Assembly Norbert Meyners, MEA 6 ILC IRENG07 WG-A 12. July 2007 Questions: Air Pads or Roller? End Cap Yoke split? (CMS first yoke discs (600mm thick) bend 14mm at full field (  force 7000t) Support QD0? Supply QD0? (Disconnect/Cool down, “Umbilical Cord”, Valve Box, Recooler, Pipe Dimensions …) Anti-DID really needed? Anti-Solenoid really needed? Vacuum (Conductance, Position of Pump, Small Pump (available?), …) Alignment (QD0, Inner Detectors, …) Magnetic HCAL end cap? Really necessary (TPC field quality)? How to fix? Support Central Beam Pipe incl. Detectors? Support/Shape LumiCAL? Position BeamCAL? Background Shielding? (Thickness, Length, Support from QD0 or Yoke or …?) Shape of the TPC …

7. MEA Machine and Experiment Assembly Norbert Meyners, MEA 7 ILC IRENG07 WG-A 12. July 2007 Detector Opening (Beam Position) Splitting the end cap yoke in beam position not necessary with Push/Pull (2m just sufficient to access the detector; Are there safety rules to be obeyed?) How to support the QD0? Where to place the recooler?

8. MEA Machine and Experiment Assembly Norbert Meyners, MEA 8 ILC IRENG07 WG-A 12. July 2007 Detector Opening (End Cap Yoke NOT split) A full end cap yoke disk would be stiffer then two half!  Prefered solution!  If not split, the End Cap Yoke has to be moved 8m aside for TPC exchange!  Can the QD0 be disconnected easily? Is this possible with a platform?

9. MEA Machine and Experiment Assembly Norbert Meyners, MEA 9 ILC IRENG07 WG-A 12. July 2007 Detector Opening/End Cap Yoke split If disconnecting of the QD0s is to difficult or time consuming, splitting the end cap yoke could help! Access to Muon System Central Rng Moving the TPC over the QD0 is at the moment not foreseen (Problem: LumiCal; Support of central beam pipe)

10. MEA Machine and Experiment Assembly Norbert Meyners, MEA 10 ILC IRENG07 WG-A 12. July 2007 End Cap Yoke split or not No final answer now! The structure of the detector should allow both. To be confirm by the design engineers! (Split yoke end caps may have more engineering difficulties due to the magnetic forces!) Answer depends mainly on the QD0 support and supply (Can the supply easily and fast (~1h) cut or not?)

11. MEA Machine and Experiment Assembly Norbert Meyners, MEA 11 ILC IRENG07 WG-A 12. July 2007 QD0 Supply, Support, “Umbilical Cord”? Is a continues cryo supply of the cryo box really necessary? The supply lines from the valve box to the QD0s should go from the bottom (or the top) through the shielding, but not from the side.

12. MEA Machine and Experiment Assembly Norbert Meyners, MEA 12 ILC IRENG07 WG-A 12. July 2007 Surface Assembly a la CMS Clear preference! We split the barrel yoke in three rings and do it like CMS. The shaft dimension are at the moment to small! Need 18,4m diameter!

13. MEA Machine and Experiment Assembly Norbert Meyners, MEA 13 ILC IRENG07 WG-A 12. July 2007 Surface Assembly a la GLD It should be possible too!.  LDC 1/8 LDC Barrel yoke ~ 440t; 1/8 LDC End cap yoke ~240t; GLD 400t  Much cabling work underground What is advantage over the CMS concept?

14. MEA Machine and Experiment Assembly Norbert Meyners, MEA 14 ILC IRENG07 WG-A 12. July 2007 Underground Cavern Size 25m floor width are only sufficient, if the walls stay inclined. Length (120m) is okay. Height (39m) is large. Beam height (8.6m) is just sufficient. Shaft diameter (16m) is to small for CMS style surface assembly (min. 19.4m).

15. MEA Machine and Experiment Assembly Norbert Meyners, MEA 15 ILC IRENG07 WG-A 12. July 2007 Platform Waiting for the talk! No final answer today! Should be possible! Answer depends mainly on the QD0 support and supply (Can the cryo supply easily and fast (~1h) cut or not?) The concrete platform looks difficult for cable and pipe routing!  Preference: Steel Platform What is the advantage to a system where all support feet would be bolted together (with cones and cups)?

16. MEA Machine and Experiment Assembly Norbert Meyners, MEA 16 ILC IRENG07 WG-A 12. July 2007 Conclusion Engineering Design has started Several open questions (internal, external and mixed) Lacking information about FD magnets and cryo supply (Dimensions, positions etc.) Question about ‘door splitting’ or ‘to use a platform’ are not decide yet. Need further information, discussion and engineering Where our assumptions right? (Push/Pull duration, …) (I hope I have covered Andrei’s wish list: General design of detector, opening and door splitting and why a particular design approach was chosen)

17. MEA Machine and Experiment Assembly Norbert Meyners, MEA 17 ILC IRENG07 WG-A 12. July 2007 End Thank you for your attention

18. MEA Machine and Experiment Assembly Norbert Meyners, MEA 18 ILC IRENG07 WG-A 12. July 2007 Additional Material

19. MEA Machine and Experiment Assembly Norbert Meyners, MEA 19 ILC IRENG07 WG-A 12. July 2007 Feet (If QD0 can not be remove) Solution for air pads. Big platform would be possible too!

20. MEA Machine and Experiment Assembly Norbert Meyners, MEA 20 ILC IRENG07 WG-A 12. July 2007 Cryo Supply (If QD0 can not be remove) Possible cryo supply routing below the detector View from below

21. MEA Machine and Experiment Assembly Norbert Meyners, MEA 21 ILC IRENG07 WG-A 12. July 2007 TPC Exchange (If QD0 can not be remove) The central beam pipe could be taken out after the central detector is move by ~1m.

22. MEA Machine and Experiment Assembly Norbert Meyners, MEA 22 ILC IRENG07 WG-A 12. July 2007 TPC Exchange (If QD0 can not be remove) The TPC can be taken after the central detector is move by >2m.