Local Supports for Inclined Layout: CERN Update D. Alvarez Feito CERN EP-DT-EO CERN, November 2016 04/11/2016

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)

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).

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)

Inclined Section: Principle (II) Module Cell (Module + cooling plate) Support Structure (Longeron + Tilted Support + Curly Pipe) 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

Inclined Section: Principle (III) Final Assembly (Support Structure + Module Cell) Gap Filler/TIM (Thermal contact between pipe & plate) Removable glue for positioning (e.g. SE4445, no thermal role) Module Cell (Cooling plate + Sensor assembly) 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

Inclined Section: Thermal Performance 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 Global TFM (˚C∙cm2∙W-1) Module ΔT~7˚C

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: Ti (Pipe) TPG-to-Pipe Interface (Gap Filler/Phase Change TIM) TPG Loaded Glue (Sensor Interface material) Silicon (Sensor) Density (kg/m3) 4620 3400 2260 1200 2330 K (W/mK) 16.4 5 1500 (//) 10 (┴) 1 124

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

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

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

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)

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)

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

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”

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)

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)

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

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

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

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

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

Prototyping Activities

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

‘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 See https://indico.cern.ch/event/571640/ for the results

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!!!)

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

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