SVD IR Mechanics

1. SVD IR Mechanics Immanuel Gfall (HEPHY Vienna) 7th B2GM

2. Status One Month Ago Immanuel Gfall (HEPHY Vienna)

3. Current Status • Parameters from the table stay the same • Added components that fix certain parameters • Interesting concept for end ring cooling • Updated isolation/support shell Immanuel Gfall (HEPHY Vienna)

4. End Rings Cooling Inlet • Split end rings • Outer 3 layers offer openings for service routing • Cooling is implemented into the ring structure • Material: Stainless steel • End rings are glued to the support cone Glueing Surface Cooling Inlet Immanuel Gfall (HEPHY Vienna)

5. Support Cone • Carbon fiber reinforced plastic • Supports end rings • Creates service paths for PXD • Houses patch panels • Fixed to beam mask Backplane Dummy Patch Panel Space Cooling Inlet Immanuel Gfall (HEPHY Vienna)

6. Beam Mask • Provides background shielding • Supports SVD • Mounted to CDC Forward Beam Mask Immanuel Gfall (HEPHY Vienna)

7. Support Assembly • Is built around beam pipe • SVD support structure is split into halves • Beam mask needs to be split End Rings Patch Panel Space Support Cone Beam Mask Immanuel Gfall (HEPHY Vienna)

8. Most Urgent Issues • Service paths • SVD space requirement • PXD space requirement • Beam mask space allocation • Slanted vs. Straight Immanuel Gfall (HEPHY Vienna)

9. Current Concept • PXD services outside of Mask • Masks can be tightly fit around beam pipe Patch Panel Location PXD Service Path Immanuel Gfall (HEPHY Vienna)

10. Service Paths Forward Region • CAD study to show if service space is available • Almost straight cable paths are possible • Study shows that there is still space left • Shown scenario is the worst case Ribbon Cables Immanuel Gfall (HEPHY Vienna)

11. Space Requirement SVD Immanuel Gfall (HEPHY Vienna)

12. Mask Thickness Study Backward • Search for areas < 10 mm • Minimal thickness ~7 mm • Additional 3 mm easily available Immanuel Gfall (HEPHY Vienna)

13. Mask Thickness Study Forward • Thinnest region ~ 5mm • Additional 2mm thickness is manageable • Mask thickness strongly depends on beam pipe shape! Immanuel Gfall (HEPHY Vienna)

14. Barrel Support • SVD 2 had a carbon fiber shell to combine forward and backward support • Belle 2 SVD needs thermal insulation (Airex cover) • Carbon fiber – Airex sandwich • Adds stiffness that protects SVD during installation • Does not add more material as is present in SVD 2 Carbon Fiber Sandwich Carbon Fiber Layer Airex Core Immanuel Gfall (HEPHY Vienna)

15. Installation Support Proposal • SVD will be very heavy • Suitable support for installation required • “Sled” from SVD 2 not sufficient • Oil drill style sliding tube for installation support Flange Oil Drill Style Tube SVD Slide Support Immanuel Gfall (HEPHY Vienna)

16. Mechanical Feasibility of Slanted Design Knee is reinforced by Crossply Conclusion: Plausible but… Immanuel Gfall (HEPHY Vienna)

17. … there are challenges • Production of ribs is difficult because of small applicable forces for clamping • Rib vibrates during routing • Water cutting could also lead to mechanical degradation • Better rib end ring link solution • Twist of sensor plane due to mechanical imperfection • There are even more! • Same problems for both options except for angle precision! • Mask weight is an issue: between 15 kg and 25 kg! Immanuel Gfall (HEPHY Vienna)

18. Conclusion • Simulations do not give conclusive answers if slanted or straight option is better • Mechanics are difficult for either solution • Mechanics do not clearly favor any solution as either solution has its drawbacks • Lets find solutions for the current situation and please stop spending more time on finding a decision! Available time is limited, we need to get going!!!! Immanuel Gfall (HEPHY Vienna)