1. MICE Collaboration Meeting at Frascati, Jun 26~29, 2005 Diffuser Mounting Design Stephanie Yang

2. S Yang, 26-Jun-20052 Positional requirement of Diffuser

3. 1046 mm 1224.5 mm z=0 -5951 mm End Coil 120 mm -6011 mm -6014.8 mm 7.6 mm -7758.5 mm Diffuser position (relative to the centre of MICE in stage VI). Q9 Diffuser 17-Jan-2005 5891 mm 250mm Iron Shield Patch panel 163mm -6173mm Courtesy of Paul Drumm

4. S Yang, 26-Jun-20054 Clearance envelop for the diffuser assembly approx. 150 mm Diffuser envelop when fully withdrawn Patch panel Tracker solenoid Iron shield Clearance gap = 250mm Patch panel Tracker solenoid Iron shield Clearance gap = 250mm 163 mm from flange face The space constraint & positioning requirement for the diffuser 95 mm Diffuser fully extended The design as it was Now it has changed!

5. S Yang, 26-Jun-20055 The task To design a mechanism that allows the insertion and mounting of the lead diffuser into the inner bore of the tracker module without having to disturb the mounting arrangement of the PID components; The tight space (about 140mm gap) between the fibre tracker patch panel and the Iron shield is such that it makes the mounting operation awkward and unreliable; This design employs a mechanism that is user friendly and guarantees the positioning of the diffuser to the required tolerance level Lets look at the design principle of that mechanism

6. S Yang, 26-Jun-20056 Insertion of diffuser assembly caused the main arm to be rotated, thereby extending the arm mechanism See animation in the next 9 pages on how this works

7. S Yang, 26-Jun-20057

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11. S Yang, 26-Jun-200511

12. S Yang, 26-Jun-200512

13. S Yang, 26-Jun-200513

14. S Yang, 26-Jun-200514

15. S Yang, 26-Jun-200515

16. S Yang, 26-Jun-200516 The Knife edge flange mounted on the top of the patch panel cover plate The original arrangement

17. S Yang, 26-Jun-200517 NO NO NO! You are not serious! Nothing can touch my Patch Panel. Imperial College Confirmation was sought from our collaborator on Fibre Tracker…………and…

18. S Yang, 26-Jun-200518 Patch Panel module Drawing received from Geoff Barber in Imperial Collage on 23 rd Jun, 2005 Courtesy of Geoff Barber

19. S Yang, 26-Jun-200519 Adaptive Knife-edge flange mounting on the end plate of the tracker module

20. S Yang, 26-Jun-200520 The need to feed the fibres from the fibre tracker out to the patch panel requires extra radial space. As a result, we have to modify the top-hat design to accommodate both the diffuser and the extra room for the fibre feed through. Radial space needed by the diffuser Space needed by the fibre

21. S Yang, 26-Jun-200521 One of the solution for fixing the diffuser mounting problem:

22. S Yang, 26-Jun-200522 3D exploded view

23. S Yang, 26-Jun-200523

24. S Yang, 26-Jun-200524 Summary We believe the diffuser works well. We have made two prototype (a scaled model and a full model) to demonstrate how the mechanism works; The need to liaise with other component supplier is essential. In the case of the patch panel we are pleased that we have identified the problem at this early stage which saved us having to redesign the diffuser mechanism although minor modification was needed to keep both sides happy; Further improvement is still possible to ease the handling of the diffuser if and when the lead plate needs replacing