1. Considerations on integration, mechanics and cooling R. Santoro, D. Perini ITS Upgrade plenary meeting, 29-May 2011

2. Outlook ITS upgrade plenary meeting  ITS integration before the upgrade  Upgrade requirement  Upgrade conceptual design  Basic ideas on cooling and thermal coupling structures R. Santoro2

3. ALICE Detector ITS upgrade plenary meeting Inner Tracking System (ITS)  Three different silicon detector technologies, two layers each  Pixels (SPD), Drift (SDD), double side Strips (SSD) Side C SSD SDD SPD SSD SDD SPD Side A 3

4. 4 Silicon Pixel Detector (SPD) ITS upgrade plenary meeting 2 layers of silicon pixel detector grouped in 2 half barrels to be mounted face to face around the beam pipe Half-barrel Outer surface Half-barrel Inner surface Half-barrel and services R. Santoro

5. SPD positioning R. Santoro ITS upgrade plenary meeting 5 Beryllium Beam pipe 1 st half-barrel SPD Internal mean radius  3.9 cm Beam pipe radius  3 cm 1 st half-barrel in place 2 nd half-barrel in place

6. Positioning of the rest of ITS and TPC ITS upgrade plenary meeting SDD+SSD moved over the SPD to form the ITS SDD + SSD SPD fully connected on side C ITS fully connected on side C TPC TPC moved over the ITS R. Santoro6

7. ITS: side view R. Santoro ITS upgrade plenary meeting 7 Absorber Forward Detectors Drift and Strip Silicon detectors Side ASide C Silicon Pixel Detectors and mechanical structure Beam Pipe

8. ITS upgrade under discussion ITS upgrade plenary meeting  Main requirements  Low material budget (less than 0.5% X/X0)  First layer as closer as possible to the interaction point to improve the impact parameter  Radius of the new beam pipe will be 20mm  Fast insertion / extraction of the inner layers: winter shut down (less than 10 weeks)  Services routed only on side A. The absorber blocks the access on the other side  New tracker in the forward region: end caps between ITS and absorber  Conical beam pipe is requested to reduce the material budget for tracks at high η  Operating at room temperature  First scenario under study: insertion of 1 extra layer of pixel detector  Reduced effort, but incompatible with the conical beam pipe  Second scenario under study: 3 new layers of silicon pixel detectors  Compatible with the conical beam pipe and the Muon Forward Tracker (MFT)  Further improvement wrt the 1 st scenario in terms of impact parameter  Third scenario under study: 7 new layers of silicon detectors  3 (or 4) layers of pixels  4 (or 3) layers of strip  End cups on both sides R. Santoro8

9. Absorber Drift and Strip Silicon detectors Side ASide C Beam Pipe Space for the new pixel detector ITS: side view

10. Absorber Drift and Strip Silicon detectors Side ASide C Beam Pipe ITS: side view Space for the conical beam pipe and the Muon Forward Tracker

11. 11R. Santoro Requirements for the Scenario 2 ITS upgrade plenary meeting 3 insertable new pixel layers + SDD + SSD and space for MFT Beam pipe20 mm Drift constrain100 mm Number of staves (#S) / layerFree Mean sensors radial position (3 layers)23mm (1st), 47mm (2nd), 90mm (3th) Detector area (rphy x z)15 x free mm2 Dead area (rphy) 2.5 mm (hybrid option) 2 x 2.5 mm in opposite sides (MALICE option) Stave length (z) if |η| = 1 and σ z =7.94cm 220mm (1st), 270mm (2nd), 365mm (3th) Power consumptionAs low as possible: reasonable range 0.25 - 0.5 W/cm2 Services 2 x #S flat cables for the power (200 mu thick?) 1 x #S optical links (1 or 2 fibers per optical link) 2 x #S cooling tubes (not needed in case of air cooling) Total material budget (X/X0) per layerAs low as possible: upper limit 0.5 % Hybrid option material budget contribution Total = 0.5% - Detector (sensor = 100 um + FEE = 50 um) = 0.16 % - Bus (half of the actual bus or even better) < 0.24 % - Mechanics/cooling = 0.1 % (200µm carbon fiber equivalent) Monolithic option material budget contribution Total = 0.39 % - Detector (50 um) = 0.055 % - Bus (half of the actual bus or even better) < 0.24 % - Mechanics/cooling = 0.1 % (200µm carbon fiber equivalent)

12. R. Santoro12 ITS upgrade plenary meeting New pixel detector: first conceptual design  3 layers of SI-pixel sensors: 1 st layer at 23 mm from the IP  Full structure divided in 2 half, to be mounted around the beam pipe and to be moved along the beam pipe towards the final position  Modules fixed to the 2 carbon fiber wheels  All the services on side A Carbon Fiber skin 3 Si-pixel Layers Carbon fiber support wheel Cooling tubes Options under discussion  rφ ermeticity  Cooling:  Water, CO2 and fluorocarbons  Single and double phase  Thermal coupling structures  Carbon foam (used in this draw)  Polyimide micro-channel  Silicon micro-channel

13. Muon Forward Tracker R. Santoro ITS upgrade plenary meeting 13 Side C Conical beam pipe Free space for the MFT Requirements  6 planes of pixel detectors between the ITS and the muon absorber (MFT)  3°- 9° of acceptance with respect to the beam line (range @ -3η)  Conical beam pipe is required to reduce the beam pipe material budget at these angles Under study  Mechanical integration  Feasibility of such a beam pipe  Coexistence of Barrel (|η| < 1) and forward acceptance

14. Carbon Foam: Conceptual design ITS upgrade plenary meeting Inspired on ATLAS and PANDA design R. Santoro14 Single module Side view Carbon fiber support skin Carbon foam Inlet / outlet Cooling tube Volume indicating sensor + electrical bus  Suitable for all the coolant options: water, CO2 and fluorocarbons  Suitable for single and double phases cooling  Studies are needed to select the material and to optimize thickness / geometry for the optimal rigidity Layout details  Carbon fiber skin 200µm thick (x/x0 ≈ 0.1%)  Carbon foam  1st layer: 500µm thick in the central part (x/x0 ≈ 0.07%)  2nd and 3rd layers: 900µm thick in the central part (x/x0 ≈ 0.125%)  Peek tube: Øext 1.2mm / Øint 1mm (x/x0 ≈ 0.12 %) Estimated material budget:  1st layer  Central part (≈0.17 %)  Along the tubes (≈0.26 % + liquid)  2nd and 3rd layers:  Central part (x/x0 ≈ 0.225%)  Along the tubes (≈0.275 % + liquid)

15. Polyimide micro-channel R. Santoro ITS upgrade plenary meeting 15 Pyralux® LF7001 (Kapton®) 24µm Pyralux® PC 1020 (polyimide) 200µm Pyralux® LF110 (Kapton®) 50µm Material budget considerations with single phases cooling  Water or C 6 F 14 Fabrication process  Starting point: sheet 50 µm of LF110  lamination 200 µm of Photo imageable coverlay  4 layers of PC1020  Creation of the grooves by photolithography process @ 180°C  glue by hot pressing the sheet 24 µm LF7001 on top of the structure  Cure all the object @ 180°C for 10 Hours.

16. Polyimide Micro-channel Layout optimization R. Santoro ITS upgrade plenary meeting 16 Analytic evaluation with simplified geometry (inlet and outlet in opposite sides) to optimize the micro- channel dimension

17. CFD analysis: water R. Santoro ITS upgrade plenary meeting 17 Outlet section channel Inlet section channel Middle section channel Axonometric view single channel L = 20 cm W= 1.6 cm T water in 15°C T water out 18°C IN OUT 16.65 °C 20.62 °C T water in 15°C T water out 18°C Upper surface N° 16 channels 800 X 200 µm

18. R. Santoro ITS upgrade plenary meeting 18  The prototype with the optimized geometry has been delivered  House made connectors for test purpose have been produced  Characterization tests are on the way:  Geometrical measurements  Ducts area: CNC Machine (Mitutoyo)  surface roughness: NTEGRA platform (atomic force microscope)  Mechanical test  Leak test  Mechanical resistance  Strain –stress behavior  Thermo fluid dynamic test  Cooling performance Vs fluid dynamic at working condition Polyimide micro-channel: on-going activities

19. Si-Micro-channel: Conceptual design  Micro-channels made on silicon plates by etching and covered with Si-plate by fusion bonding  no CTE mismatch and high pressure resistance  Two layouts are under discussion  Distributed micro-channels: material budget equally distributed below the sensitive area  Sideline micro-channels: micro-channels confined at the chip’s border, where there is the major power consumption (first prototype in July) Distributed micro-channels x/x0 < 0.16% x/x0 = 0.05% (no liquid inside) x/x0 = 0.08% (C4F10) Further considerations  Suitable with double-phases cooling (C02 or fluorocarbons)  Simulation and R&D are needed  Limitation: the length of the wafer is presently <= 100 mm  Layout optimization and services to be studied Sideline micro-channels hole %X0 = 0 in the sensitive area !! Common Inlet pipe Module n Module n+1 Common return pipe

20. Summary R. Santoro ITS upgrade plenary meeting 20  The ITS upgrade requirements has been discussed  Main focus was on the 2 nd scenario: 3 new layers of pixel detectors with the possibility to allocate a conical beam pipe  A first mechanics conceptual design was shown  Big effort in the integration is now needed  Material budget of the order of 0.1% for mechanical support and cooling is the goal at least for the first layer  The different options concerning cooling and thermal coupling were discussed  Carbon foam: simulation and material procurement for tests are needed  Polyimide micro-channel: simulation is progressing well and the prototype has been delivered. The tests are on the way  Silicon micro-channel: discussions on prototype design is started

21. Spare R. Santoro ITS upgrade plenary meeting 21

22. R. Santoro ITS upgrade plenary meeting 22 1 st layer 2 nd layer 1,5 x/x0 Skin0,1 Foam 0,3000,042 Tube0,12 Total0,262 1,6 x/x0 Skin0,1 Foam 0,4000,056 Tube0,12 Total0,276

23. CFD analysis: C 6 F 14 R. Santoro ITS upgrade plenary meeting 23 Outlet section channel Inlet section channel Middle section channel Axonometric view single channel IN OUT 17.16 °C 26.01 °C T C 6 F 14 in 15°C Upper surface T C 6 F 14 out 18°C L = 20 cm W= 1.6 cm T water in 15°C T water out 18°C N° 16 channels 800 X 200 µm Power consumption 0.5 W/cm2

24. Outlet section channel Results CFD analysis [H 2 O vs C 6 F 14 ] Cosimo Pastore & Irene Sgura ( Politecnico di Bari & INFN Bari) 20-04-2011 16 Assonometric view single channel Outlet section channel H2OH2O C 6 F 14 IN OUT CONSIDERATIONS A) @ height channel 200  m the thermo-fluid dynamic H 2 O behavior IS MORE EFFICIENT then C 6 F 14. B) WATER doesn’t allow (very difficult) to reduce the height of the channel minor then 200  m due to the pressure drops (no leak- less mode)

25. μ -channels in NA62 R. Santoro ITS upgrade plenary meeting 25 Channels 100 µm deep Manifolds 280 µm deep Interface to the connector First prototypes tested successfully! IN OUT flow Pictures taken from NA62 GTK WG meeting presentation - P. Petagna NA62 requirements: Acceptable DT over sensing area ~ 5 °C Dimensions of sensing area: ~ 60 x 40 mm Max heat dissipation: ~ 2 W/cm 2 Target T on Si sensor ~ -10 °C

26. Forward spectrometer – conceptual design Conceptual design – Highly segmented calorimeter at small angles Electromagnetic front section – Sandwich silicon-tungsten – 30 longitudinal layers – Sensitive layers: MAPS technology, e.g. MIMOSA/ULTIMATE (20  m x 20  m) Hadron section – Sandwich tungsten/iron-scintillator – 60 longitudinal layers – Sensitive layers: scintillators (3cm x 3cm) read out by Multi- Pixel Avalanche Photodiodes (ala PSD @ NA61) – Rebuilt (wide gap) and relocated compensator magnet – Low mass beam pipe – Silicon pixel tracker close to the IP R. Santoro26