1. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand LHCb Vertex Detector System: Status Report J.F.J. van den Brand Subatomic Physics Group, VUA - NIKHEF Review of TP design mechanics, vacuum system, cooling system. Requirements more cooling power, intermediate Y positions of two halves Milestones

2. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Mechanics: “TP” design Side flange Bending hinges Detector support and cooling Bellows (22000 signal wires) Support frame Si detector moves by 30 mm only two positions: open or closed !! See LHCb 99-042/VELO top half = bottom half

3. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Requirements on VD design VELO workshop in Amsterdam (April ‘00): Top/bottom halves should have intermediate steps (not only open/closed), with `relaxed’ overall position accuracy (0.3 mm). Only useful if we can acquire meaningful data in intermediate positions !  trigger algorithm Higher cooling power required (20 W/module  40 W/module) to accommodate for backup solution SCTA/velo. Should be no problem for CO 2 cooling system, but is it realistic at all ?  thermal modeling needed

4. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Modified design VELO Design: Single flange XY table CO 2 cooling WF suppressors Second. vacuum Studied assembly alignment To do further design FEA

5. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Vacuum tank new FEA required (probably additional ribs are needed) flange will be on inside of LHC ring solves lack of space issue on outside of ring all feedthroughs on the same big flange all cables and repeater cards on same side (present choice of feedthrough limits total number of pins to about 25,000 !!)

6. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Detector Modules Number of planes: 25 Discuss Liverpool delivers modules 40 W, 1 m cable, 50 % isolation thickness, 10 - 15 K  T, radiative cooling 44 pins, 440 / module

7. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Detector Mounting Install Modules 3D alignment Mount References

8. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Wake field Suppressor Central cooling line Temperature sensors (2 per station, 4 wires per measurement

9. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Wake field Suppressor Welding tests: 250  m Al FEA: Beryllium

10. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Foil design options (continued)

11. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Foil design options (continued)

12. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Foil design options (continued)

13. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand CO 2 Cooling Tubes Cooling tubes 1.1 (0.9) mm S.St. Welding and brazing

14. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand CO 2 Cooling Tests Cooling system -30 o C 40 W/module

15. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Detector Assembly External reference marks Wires fed through 7 bellows Structure connects to frame

16. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Support frames No more problems of bending: stiff, stable structure XY-table can move down enough to allow insertion of complete detector (tilting mechanism no longer needed) frames not any longer `in our way’ (more accessibility to critical items of VD)

17. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Support frames FEA studies ongoing Connect to outside Allows vacuum tests

18. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Support frames How to mount? How to align? Vacuum testing? Cabling? Rigidity?

19. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Support frames Wake field screens 3-point support Alignment XY table  5 mm, - 25 mm Reset switches LVDTs Step motors

20. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Support frames S.St. vacuum vessel Exit foil by CERN RICH conflict? Mounting RF shield? Coating - Au,.. z = 970 mm Acceptance  300 mrad (hor.)  250 mrad (vert.) from IP zero bunchlength

21. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Support frames Steel frame Fill with sand Dimensions 1630 mm 1500 mm 1200 mm Align frame within 1 - 2 mm Fix frame

22. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Detector and support frame both halves on same side VD easier to mount and position in the tank install complete VD at once the two halves are no longer interchangeable

23. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Vacuum Tests

24. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Vacuum Tests

25. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand TP design center frame New design Sideways accessibility (1) Side wake field suppressors Ti evaporator No room on the sides !

26. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Sideways accessibility (2) More access to critical WF suppressor Much room left on one side of the tank  2ary vacuum pumps (pumping on the detector boxes is more efficient)  if required, a Ti eva- porator with much more favorable design conditions

27. vrije Universiteit amsterdam Milan, September 25, 2000 VELO System J.F.J. van den Brand Cooling system with mixed-phase CO 2 *