1. Antti Onnela CERN – EP – Detector Technologies group
ECFA High Luminosity LHC Experiments Workshop Technology progress and R&D on mechanics
Antti Onnela CERN – EP – Detector Technologies group

2. ECFA 2016: Technology progress and R&D on mechanics / A. Onnela
Outline
Focus on mechanics of the LHC Tracker upgrades.
Substantial efforts on mechanics also in other projects, e.g. LHCb VELO, CMS HGCAL, not covered in this talk.
Development of local support structures: Staves, truss- structures, I-beams, disks, …
Thermal interface materials
Development of tilted detector geometries
Sources for further information
Closing remarks: Common developments, sharing of efforts?
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

3. ECFA 2016: Technology progress and R&D on mechanics / A. Onnela
Development of local support structures: Staves, truss-structures, I-beams, disks, …
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

4. ALICE ITS Upgrade STAVES
Now in production phase
Inner Barrel STAVE
Flexible PCB
9 sensors
Cold Plate
Space Frame
Connector
Fitting
Space Frame
Cold Plate
0,3m
Pixel operation temperature < 30°C
Pixel max temperature non-uniformity < 5°C
Cooling: Mono-phase H2O leak-less
Outer Barrel STAVE
Power bus
Space Frame
Cold Plate
2x7 sensors
FPC
1.5m
Space Frame
Cold Plates
Inner Barrel
Outer Barrel
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

5. ECFA 2016: Technology progress and R&D on mechanics / A. Onnela
Light-stiff
mechanical support
ALICE ITS Upgrade Inner Barrel STAVE
Positioning
Cooling
Mechanics
0.3 m, 1.7gr
Light-high thermal conductive
Cold plate
Light-stiff mechanical Spaceframe
Stave Precise positioning
end pieces
Coldplate
Spaceframe
Leak-less water cooling
Pipe Burst 51bar
Manual Layup
Filament winding
High-conductivity (brittle) carbon-fibres and carbon sheet
High-modulus carbon-fibres (less brittle)
Amec FGS_003
K13D 2U
Pyre M.L.
fleece
M60J
Embedded polyimide pipes
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

6. ECFA 2016: Technology progress and R&D on mechanics / A. Onnela
ALICE ITS Upgrade Outer Barrel STAVE
Positioning
Positioning
Mechanics
Cooling
1.5 m, 40 g
1.5m, 21g
Connection between
Spaceframe and Cold plate
Stave Precise positioning
End Pieces
Light-stiff mechanical Spaceframe
Light-high thermal conductive
Cold plate
Manual layup
M55j thread
Polyimide pipes
Filament deposition
Carbon paper (FGA)
Carbon fleece
Carbon PEEK machined end piece
M55j prepreg
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

7. On-going development of local support structures
Ref: ATLAS Phase2 Pixel (CERN)
Self-mass ~40 g/m
Supports at 1 m distance
2 kg load  0.3 mm displ.
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

8. ECFA 2016: Technology progress and R&D on mechanics / A. Onnela
I-beam concept
Ref: ATLAS Phase2 Pixel (Berkeley)
Alternating 4x2 and 4x4 I-beams
4x2 I-beams
Measured flatness on final module mounting surface < 0.1 mm
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

9. Sandwich plate structures
Ref: LHCb UT (Syracuse)
High-conductivity carbon-fibre/ polymer skins
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

10. Sandwich plate structures
Ref: CMS Tracker Upgrade (Fermilab)
Ref: Atlas Tracker Upgrade (DESY)
End-cap petals
Barrel ‘planks’ with PS modules
Allcomp K9 graphite foam
End-cap disks with PS modules (modules mounted on disk surface) 2S modules (modules mounted on aluminium inserts)
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

11. Thermal interface materials
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

12. Module mounting with Thermal Interface Material
Ref: LHCb UT (Syracuse)
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

13. Selecting of phase-change Thermal Interface Materials
A. Mussgiller, DESY
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

14. TIM handling and radiation resistance
A. Mussgiller, DESY
Manufacturers advice to use pressure when applying the TIM. With thin silicon sensor modules this cannot be done, therefore tests done with self-weight of the ‘module’.
Further tests and development of work-methods needed to confirm use with real, large-size (5 x 10 cm) modules.
Experience with smaller pixel modules now being gained e.g. in CMS Pixel Phase 1 upgrade.
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

15. Development of tilted detector geometries
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

16. ECFA 2016: Technology progress and R&D on mechanics / A. Onnela
Tilted geometries
ATLAS Tracker Upgrade
CMS Tracker Upgrade
In these cut views the tilted geometries appear as rather simple.
The challenges are in the 3D integration and in the mechanics…
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

17. ECFA 2016: Technology progress and R&D on mechanics / A. Onnela
Tilted geometries
Ref: ATLAS Phase2 Pixel ALPINE concept (Annecy & Grenoble)
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

18. ECFA 2016: Technology progress and R&D on mechanics / A. Onnela
Tilted geometries
Ref: ATLAS Phase2 Pixel SLIM concept (Geneva & CERN)
Another option under study: a spiralling cooling pipe
Cooling block in porous graphite
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

19. ECFA 2016: Technology progress and R&D on mechanics / A. Onnela
Tilted geometries
Carbon-fibre/Airex sandwich ring
Red: CMS Phase 2 Tilted TBPS (CERN)
Tilt angle and connection to cooling pipe with pieces in aluminium/carbon-fibre composite. Properties in fibre-plane:
CTE: 4 ppm
Thermal cond.: 230 W/mK
out of fibre-plane:
CTE: 24 ppm
Thermal cond.: 120 W/mK
Module support/cooling plate (seen from back-side)
Diam: 600 mm (layer 1) – 1100 mm (layer 3)
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

20. From physics layout model to 3D CAD
Ref: CMS Phase 2 Tilted TBPS (CERN)
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

21. Sources for further information on current mechanics developments
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

22. Sources for further information
ECFA High Luminosity LHC Experiments Workshop 2014:
C. Gargiulo, Lightweight thermomechanical structures
E. Anderssen, Integration and Environment for Upgrade Trackers in High Luminosity LHC
Composites Workshop at Berkeley, Feb-March 2016:
Composites design, manufacture and applications.
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

23. Sources for further information
Forums on Tracking Detector Mechanics
2012, CERN
2013, Oxford (UK)
2014, DESY (DE)
2015, NIKHEF (NL)  
2016, Bonn (DE)
2017, Marseille (FR) 3 days in late May – early July, exact dates to be confirmed. Announcements will be sent to LHC experiment distribution lists.
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela

24. ECFA 2016: Technology progress and R&D on mechanics / A. Onnela
Closing remarks
Are there areas for common developments and sharing of efforts?
Choice of thin-walled cooling pipes and qualification of their joining techniques.
Qualification of adhesives and thermal interface materials for HL-LHC radiation doses (beyond 1 MGy levels)
We are missing new CERN Yellow books for HL-LHC, to complement those of the 80’s and 90’s…
Grouped procurements of high-end, expensive carbon-fibre prepregs with limited storage life (typically 6 months) and fairly big minimum procurement quantities (beyond usual R&D needs within one team).
CERN EP-DT Composites lab can help in procurement coordination and technical matters. Contact persons:
Feed-back, suggestions … and contributions are welcome!
ECFA 2016: Technology progress and R&D on mechanics / A. Onnela