Mechanical Integration Issues

1. Mechanical Integration Issues Bill Wisniewski

2. Integration for TDR • Technical questions to be resolved: • Reuse of BaBar steel yoke: • The steel can be reused for the IFR. • Better coverage for outermost barrel layer if the suspension of the sextants is modified. • Engineering on supporting sextants at corners instead of multiple flats at the ends of the sextants is ongoing: • Are the changed deflections harmful? The plate deflections in the sextants may increase and pose a limit on detector thickness/installation. • Need to understand the added load from filling additional gaps as well. • Is the support provided to DIRC, EMC compromised? • Needs to be resolved by year’s end. Massimo is modeling the steel and alternatives. • BaBar construction of little help here, since most of history is lost, but searching continues.

3. Integration for TDR • More on the steel: plug changes • DCH exploring option of thinning the electronics on the chamber, moving processing off the backward end of the chamber. • BaBar (left): 4 holes are 130mm in diameter: 2 used for DCH cables, 1 for DCH services, 1 for support tube. • SuperB: DCH would need 3+ holes to carry the cables. Enough space. But…

4. The Plugs • Though there is enough space for the cables in existing holes, there will be insufficient space for services. Could add extra holes. But… • The holes are poorly located: the backward EMC will block the holes. • We also need to take out the backward EMC cables. • Forward endplug will need to be modified to accommodate beam pipes. • Particular geometry of the existing forward and backward plugs was chosen to limit the field on PEPII Q2 magnets. This constraint is gone. Backward plug, with compensating coil and steel cylinder shield also limited field on DIRC SOB PMTs. • Change in needs at forward and backward ends means that design of plugs needs to be reinvestigated. Forward plug may only need to be ‘shaved’. Backward EMC design and channel count pushes for a monolithic annulus. DCH and EMC cables push for slots distributed in phi? Mechanical stability of altered plug in field? • Concern to be kept in mind when considering redesign: effects on central field (expect little); effects of unbalanced forces on the solenoid coil. • Overall understanding of the field may be very time consuming. Bill Wisniewski

5. Integration for TDR • More details of the steel: • Plug redesign consequences need to be done in time for detector design finalization (DCH, BEMC) • Would be best to have detailed plug design by TDR, but likely to be OK if it slips later. • Cryo Plant: • Credible cryo plant solution. Needed for costing more than as a technical issue. Conservative estimate for the TDR may suffice. • Weisend, before he left, did an evaluation of the existing plant at Frascati…..

6. Cryogenics Plant • Does the DAΦNE Frascati plant have sufficient capacity for the superconducting IR magnets and the detector solenoid? • Weisend asked to look at this. Data gathered from Tomassini and Monarche (thanks!). Bill Wisniewski

7. Cryogenics Plant 1st Look Personnel issue: Weisend left SLAC for MSU. May have some cycles before September to refine the evaluation, but we need a long term solution. Perhaps Craddock, but better if a local engineering takes this on. Bill Wisniewski

8. Integration for TDR • Technical questions to be resolved: • Transport of detector components: • Coil can clearly be transported via air. Frame exists, but part is damaged and needs to be re-made. Will be done as part of D&D. • Sufficiently mature for TDR now. • EMC barrel: engineering analysis that transport of the barrel as a monolith is possible. Credible scheme for transport (credible preliminary design needed). Issue: Do we need to disassemble EMC? • Needs ~6 engineer months? Needed for costing and if not possible, may have schedule implications. • Finding the lost: CAD files found, includes reasonably detailed 3D… • Needs to be done ~quarter year before the TDR is complete.

9. Integration for TDR • Technical questions to be resolved: • Transport of detector components: • Steel: cost estimate for transport needed for TDR. • White paper estimate will be crude. • Needs perhaps purchasing agent + engineer time. • DIRC bar box support frame transport analysis and design of support frame cradle for transport. • Needs a few months of engineering. Would be good to have for the TDR, but this is a less pressing issue than EMC transport.

10. Integration for TDR • Technical questions to be resolved: • Preliminary design for the support of the SVT and final focus. • Needs settled IR. • Cryostats define the inner radius of DCH. Cryostat design is preliminary. Firm up. • Credible design for cantilever support, installation scheme needed (push-pull).

11. Integration for TDR • Technical questions to be resolved: • Support of tungsten shields • Need exploration/analysis of different support points: • EMC? But will the flexible supports bear this new load at the forward end? • DIRC SST at rear? Backward bridge/plug? Effects on detector as a whole? • DCH? End wall thickness? • Newer item, not clear how much engineering time this nightmare needs. Need a credible conceptual design for the TDR, a quarter year in advance of the TDR. This one is hard.

12. Integration for TDR • Technical questions to be resolved: • Support of Backward EMC: • Off the backward plug? A separate spider? • Concept needed for TDR.