Design concept

1. Tracker Phase 2 Mechanics Review, 26 August 2013Status of the Outer Barrel designThis presentation bases on Outer Barrel design work and inputs during 2012-2013 by DuccioAbbaneo, Giovanni Bianchi, Aleksis Chávez Niemelä, Antonio Conde Garcia, Jordan Degrange, Tristan Falcy, Alan Honma, Riikka Häsä, Luc Kottelat, Nick Lumb, Stefano Mersi, Andreas Mussgiller, Antti Onnela Antti Onnela, CERN

2. Design concept Bases on re-using the current TOB design • 1 support wheel • Rods installed from the two ends Outer Barrel (3 layers) 2S modules PSmodules 2S module ~ 10 cm x 10 cm Rod with 2S modules ~ 120 cm x 15 cm Antti Onnela, CERN

3. Design concept Outer Barrel base-line with 6” wafer modules Outer Barrel 2nd variantwith 8” wafer modules 2S modules 4464 from 6” wafers [3776 from 8” wafers] Rod with 12 [or 8 / 16] 2S modules 372 (186 per end) [376 (188 per end)] Antti Onnela, CERN

4. Design concept Outer Barrel (3 layers) 2S modules 4464 from 6” wafers [3776 from 8” wafers] Rod with 12 [or 8 / 16] 2S modules 372 (186 per end) [376 (188 per end)] In the old TOB, with 6 layers 5208 modules 688 rods (344 per end) Antti Onnela, CERN

5. Wheel + Rods • Wheel = 4 disks joined together by 3 inner and 3 outer cylinders • Rods are half length of the barrel, with overlap in middle. • Rods inserted from the two ends. Each rod supported by two disks. Antti Onnela, CERN

6. Rod support and positioning • Precision support inserts in the Disks • 4 spherical contact surfaces in each rod Antti Onnela, CERN

7. Rod support and positioning • Precision support inserts in the Disks • 4 spherical contact surfaces in each rod Antti Onnela, CERN

8. Critical: Rod cross-sectional size 4 mm more than in the old TOB, due DC-DC converters. Reducing converter height would be very useful to gain assembly clearances. C-profile needs to be 2 mm narrower than in old TOB, to make rod fit Just enough, but with no margin Antti Onnela, CERN

9. Modules on the Rod This version misses still the possibly needed 5th cooling contact below the service hybrid Antti Onnela, CERN

10. Critical: Module cooling • In old TOB and our first upgrade studies: Cooling pipe on the outside of the Rod C-profile • Now studying cooling pipe inside Rod C-profile, as close as possible to the modules. Tight space inside the Rod, but does not seem impossible.Geometrically different from the old version, strength of insert glue joints needs to be carefully re-studied. Antti Onnela, CERN

11. Cooling pipe next to the modules? • Thermally attractive. • Very small clearances, but possibly enough. • Cooling pipe diameter becomes critical. In this study pipe diameter 2.0 mm, target range 1.5 – 2.0 mm. • Recent design idea, integration not proven yet. Antti Onnela, CERN

12. Services arrangement Power cables and optical fibres, two options: • Connectors at the end of each rod. Services installed, connected and routed outwards after Rod installed inside the Wheel. • Connectors inside the rod (at each module), rod installed with services pigtail, which need to be long enough to reach TK Bulkhead or PP1. Antti Onnela, CERN

13. Cooling Two rods in series gives “CO2-suitable” cooling circuits: • 2 x 2.5 m = 5 m pipe length with 1.5 - 2 mm pipe diameter. • 84 W per line • 186 lines in total (93 per end) • 186 supply capillaries from manifolds at TK Bulkheads • Return pipes (size?) to manifolds at TK Bulkheads. Alternative: Return manifolding at the TOB end. Antti Onnela, CERN

14. Nexttasks with TOB design • Verify the 3D integration with the ‘inside-Rod’ cooling pipe concept • Add 5th cooling contact for each module. • Does everything fit correctly? • Study more in detail the new type of module support/cooling inserts • Module positioning • Cooling performance, contact area to cooling pipe • Strength of the glue joints under thermal and mechanical loading • Study the cooling pipework more in detail:pipe diameters, connections, manifolding. Antti Onnela, CERN

15. Outer Barrel design work in summary Strengths: • Wide reuse of existing and proven solutions allows fast and efficient progress in the design, and helps a lot in the planning and cost estimates. Specific challenges: • In order to fit in the Wheel the Rods can have only a limited thickness + width. • Dimensions of service board electrical and optical components are critical for success. • Need to design and build strong, stable, and geometrically precise Rods. • We know how to do that, providing that the Rod design stays reasonably similar to the old one. Bigger changes will need more attention in the design and R&D phase. • Efficient and reliable (!) cooling for every module. • Moving the cooling pipe inside the Rod is step towards improvements, but also adds space complications. • Cooling pipes and their connections must be of top quality, and of conservative design ‘not optimised for last gram’. • Access to the Modules and Rods in the assembled Wheel is very difficult and time-consuming. • Assembled Rods must be rigorously pre-tested to minimize risks of later discovery of problems. Antti Onnela, CERN

16. Back-up slides Antti Onnela, CERN

17. Earlierstudies (year 2012) • Module + Rod integration • Tight clearances (like in the original TOB…), but seem solvable • Module positioning concepts and precision. • Thermal contacts between Modules and cooling pipe • Mechanical properties of adhesives used in cooling pipe contacts. • Adaptors for holding 2S modules on existing spare TOB rods. Size of DC-DC converter and optical link Overlaps between modules and rods Antti Onnela, CERN

18. Rod without modules Antti Onnela, CERN