Local Supports for Inclined Layout: CERN Update

1. Local Supports for Inclined Layout: CERN Update D. Alvarez Feito CERN EP-DT-EO CERN, November 2016

2. Local Support Designs for Inclined Layouts • Stave/Longeron Approach • Conservative approach (two pipes per module) • Intermediate approach (single pipe per module, soldered interfaces) • Aggressive approach (single pipe, glued interfaces) • Tilted Rings (e.g. CMS)

3. Aggressive approach: Curly Pipe Design • Design solution developed for SLIM v3.0 • Compatible with common inclined effort (“Aggressive Version”) • Main Objectives: • Radical reduction of the cell mass while meeting TFM requirements • Eliminate the need for solder interfaces • Minimise the effect of the Ti pipe on the positioning of the modules (e.g. introduce local CFRP supports) • Minimise ΔT within the module • Facilitate module loading in “flat” configuration • Allow for re-workability/replacement of defective modules (i.e. modularity).

4. Inclined Section: Principle (I) • Thermal Management • Curly Pipe (i.e. smooth 3D loops in the cooling line) • Increase usable pipe surface • Reduce distance from pipe to sensor • Introduce flexibility in pipe • Independent of “tilt” angle • Cooling plate • “Machined” graphite plate • Flat TPG (reinforced if needed) • Loading on flat surface • Local CFRP support for positioning and stability • DOES NOT PLAY ANY THERMAL ROLE (thus, not included in thermal FEA) • Support two adjacent tilted modules (minimise #parts, increase stiffness) • Define positioning of cooling plate (locator system, e.g. pins, ruby balls) • Constrain the pipe (epoxy glue, not conductive)

5. Inclined Section: Principle (II) Support Structure (Longeron + Tilted Support + Curly Pipe) Module Cell (Module + cooling plate) Cooling Plate (TPG, graphite) Silicon Sensor (Includes machined holes/locators) Conductive glue Loop Pipe (glued to support/longeron) CFRP Support (glued to longeron) CFRP support includes locators for module cell (pins, ruby spheres) Longeron

6. Inclined Section: Principle (III) Final Assembly (Support Structure + Module Cell) Gap Filler/TIM (Thermal contact between pipe & plate) • Module cell fixed to support structure: • Gap filler/TIM for thermal contact • Removable glue (e.g. SE4445) for securing positioning /pressure (NO THERMAL ROLE) • Matching locator system between cooling plate and CFRP local support Removable glue for positioning (e.g. SE4445, no thermal role) Module Cell (Cooling plate + Sensor assembly)

7. Inclined Section: Thermal Performance Global TFM (˚C∙cm2∙W-1) • Graphite plate (porous or iso-graphite) • Example: Porous graphite plate (ρ=1000kg/m3, K=86Wm-1K-1, 0.36g) • Flat TPG plate (see next slides) • No machining required • High in-plane thermal conductivity → Lower ΔT within the module Module ΔT~7˚C

8. Thermal Performance: TPG Cooling Plate • FEA Assumptions: • Module size: 40 x 19 x 0.35 mm • TPG Size: 38x19 mm (thickness between 0.1-0.6mm) • Heat flux: 0.7W/cm2 • HTC inside the pipe: 8000 W∙m-2∙˚C-1 • Thickness of Gap filler/TIM between pipe and TPG plate: 0.25mm • No environmental convection/radiation • No thermal contact losses • No contribution from local support or additional CFRP reinforcement • Material properties:

9. Thermal Performance: TPG Cooling Plate Global TFM (˚C∙cm2∙W-1) • Full contact with the pipe loop: TPG 0.3mm thick

10. Thermal Performance: TPG Cooling Plate α • Partial contact with the pipe loop: • Section of the gap filler removed to reduce ΔT within the module

11. Thermal Performance: TPG Cooling Plate α • Partial contact with the pipe loop: • Section of the gap filler removed to reduce ΔT within the module

12. Local CFRP Support • Glued to truss • Incorporate groove to position and glue the pipe (“buried” pipe) • Incorporates locator system (e.g.pins,ruby balls) to position module cell • Ideally, it would support two tilted modules from adjacent rows • Ongoing design optimisation (geometry, layup, longeron compatibility) • Prototyping to follow (3D printed mould) Not realistic geometry (shown only for illustration purposes)

13. Local CFRP Support • Glued to truss • Incorporate groove to position and glue the pipe (“buried” pipe) • Incorporates locator system (e.g.pins,ruby balls) to position module cell • Ideally, it would support two tilted modules from adjacent rows • Ongoing design optimisation (geometry, layup, longeron compatibility) • Prototyping to follow (3D printed mould) Not realistic geometry (shown only for illustration purposes)

14. Local CFRP Support • Open design + stiffening rib • Tubular design (N.Geffroy) Not realistic geometry (shown only for illustration purposes)

15. Flat Section: Principle (I) • Thermal Management: • Single, straight pipe • Cooling TPG Plate (machined with longitudinal groove) • “Machined” TPG plate (reinforced if needed with thin CFRP plies) • Thermal contact with pipe via removable interface (gap filler /TIM) • NO soldered interface • Loading on flat surface • Local carbon support for positioning and stability • DOES NOT PLAY ANY THERMAL ROLE (thus, not included in thermal FEA) • Support two adjacent flat modules (minimise #parts, increase stiffness) • Define positioning of cooling plate (locator system, e.g. pins, ruby balls) • Constrain the pipe (epoxy glue, not conductive) • CFRP “Ribbon” or “Graphite Block”

16. Flat Section: Principle (II) Module Cell (Module + cooling plate) Module Machined TPG Support Structure (Longeron + Tilted Support + Pipe) Conductive glue (TIM) CFRP Supports (glued to longeron) Ti Pipe (glued to CFRP supports)

17. Flat Section: Principle (II) Gap filler/Phase Change TIM (thermal contact Ti-TPG) Removable glue for fixation (e.g. SE4445, no thermal role) Module Cell (positioning via locator system in supports/cold plate)

18. Thermal Performance: TPG Cooling Plate Global TFM (˚C∙cm2∙W-1) • Example (0.4mm thick plate): Module ΔT (˚C)

19. Thermal Performance: TPG Cooling Plate • TPG dimensions can be selected to match the TFM requirements for each layer while minimising the cell mass and the ΔT within the module. • Parametric study Module Size (W,L): 38x40mm

20. Thermal Performance: TPG Cooling Plate • TPG dimensions can be selected to match the TFM requirements for each layer while minimising the cell mass and the ΔT within the module. • Parametric study Module Size (W,L): 38x40mm

21. Thermal Performance: TPG Cooling Plate • TPG dimensions can be selected to match the TFM requirements for each layer while minimising the cell mass and the ΔT within the module. • Parametric study Module Size (W,L): 38x40mm

22. Thermal Performance: TPG Cooling Plate • TPG dimensions can be selected to match the TFM requirements for each layer while minimising the cell mass and the ΔT within the module. • Parametric study Module Size (W,L): 38x40mm

23. Prototyping Activities

24. ‘Curly’ Pipe: Initial Thermal Tests • Very preliminary thermal tests (stainless steel pipes) • Comparison between straightpipe and line with loops (same length) • Homogenously distributed heat load using pipe resistivity (50W) • CO2 inlet temperature set to -20°C N. DIXON -15.3°C -15.1°C -14.8°C -15.4°C -16.0°C

25. ‘Curly’ Pipe: Latest Thermal Tests • Assess performance of the ‘curly’ pipe for different phi positions and identify potential problems • Stainless steel pipe with 5 loops and simplified module cells: • Al cooling plate with machined groove (gap filler + clamp) • Kapton heater • NTC at the furthest corner N. DIXON; R. GOMEZ Seehttps://indico.cern.ch/event/571640/ for the results

26. Curly Pipe: New Prototypes • 4 new prototypes produced by external company (stainless steel, OD4mm/ID2mm) • Modified geometry proposed by the company to ease manufacture • Plan: • Assess new geometry from the fluidic standpoint (i.e. CO2 behaviour) in different Φ positions • Measure Δp to validate CO2 simulations (COBRA) • Measure HTC? • If results are positive, we will launch prototyping campaign with Ti pipes (new jigs will be required, so we should converge to a suitable pipe size beforehand!!!)

27. EP-DT Thermal Set-up: Upgrade • Monitor CO2 vapour quality

28. Support Structures: Longerons • Truss Longeron: • Four new 1m-prototypes of the truss longeron (“hybrid” construction) • Production rate: 1/day (including all preparation steps) • Shell Longeron: • In-house production of shell longeron following procedure developed at Composite Design F. BOYER