1 outer barrel, phase 2 mech review 26 aug 2013, indico: 246502 antti onnela, cern tracker phase 2...

1Outer Barrel, Phase 2 Mech Review 26 Aug 2013, indico: 246502 Antti Onnela, CERN

Tracker Phase 2 Mechanics Review, 26 August 2013

Status of the Outer Barrel design

This presentation bases on Outer Barrel design work and inputs during 2012-2013 by

Duccio Abbaneo, 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

2

Design concept

Bases on re-using the current TOB design• 1 support wheel• Rods installed from the two ends

Outer Barrel, Phase 2 Mech Review 26 Aug 2013, indico: 246502 Antti Onnela, CERN

2S module~ 10 cm x 10 cm

Rod with 2S modules~ 120 cm x 15 cm

Outer Barrel (3 layers)

PS modules

2S modules

3

Design concept


2S modules4464 from 6” wafers[3776 from 8” wafers]

Rod with 12 [or 8 / 16] 2S modules372 (186 per end)[376 (188 per end)]

Outer Barrel base-line with 6” wafer modules

Outer Barrel 2nd variantwith 8” wafer modules

4

Design concept


2S modules4464 from 6” wafers[3776 from 8” wafers]

Rod with 12 [or 8 / 16] 2S modules372 (186 per end)[376 (188 per end)]

In the old TOB, with 6 layers5208 modules688 rods (344 per end)

Outer Barrel (3 layers)

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.

6

Rod support and positioning

• Precision support inserts in the Disks• 4 spherical contact surfaces in each rod


7

Rod support and positioning

• Precision support inserts in the Disks• 4 spherical contact surfaces in each rod


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

9

Modules on the Rod


This version misses still the possibly needed 5th cooling contact below the service hybrid

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.


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.

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.

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.

Layer L1 L2 L3 Totals# mod 1152 1488 1824 4464along phi 48 62 76mod/rod 12 12 12W/mod 3.5 3.5 3.5W/rod 42 42 42W one end 2016 2604 3192 7812W total 4032 5208 6384 15624

14

Next tasks 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.


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.


16

Back-up slides


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Earlier studies (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.


Overlaps between modules and rods

Size of DC-DC converter and optical link

18

Rod without modules


1 outer barrel, phase 2 mech review 26 aug 2013, indico: 246502 antti onnela, cern tracker phase 2...

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