PHENIX FVTX Status of Mechanical and Thermal Design Work Eric Ponslet, Shahriar Setoodeh, Roger Smith HYTEC Inc. Los Alamos, NM May 2, 2007

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 2 Final Design Package Final Report and Drawing Package –Documents the Preliminary Design of FVTX structures and cooling system –delivered to LANL on 04/24/07 –Available on Twiki at Report: HTN Drawings: 111-PHX to -3012

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 3 Latest Baseline Design Change since last status presentation (UNM, March 12, 2007) –Modules staggered in Z to provide sufficient space on HDI for FPHX chips, wire bonding pads, and decoupling capacitors Modular Design –Sensor module (“wedge”)  Half Station  Half Cage  FVTX Wedge built on a Graphite Fiber/Cyanate Ester Thermal Backplane –Serves as structural support and heat transfer path to edge cooling –0.76mm thick K13CU/CyE Very high thermal conductivity fiber Wedges are Fastened to Support Panel –Two alignment pins (ceramic/glass?) and 3 screws (nylon) per wedge –RT-cured silicone bridge provides thermal interface to cooled support panel –Allows replacement of single defective wedge BUT: requires cutting the Silicone thermal bridge Half-Disk Support Panel and Support Cage –Sandwich construction: Graphite fiber (M55J) faces and aluminum honeycomb Liquid Cooling –Tube embedded in support panel in place of core, near OD of half disk –Single phase coolant at high flow rate (turbulent)

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 4 Two variations: upstream and downstream –HDI tail folded forward or backward Sensor Module Backplane (0.76mm graphite fiber composite) Screw (nylon) Pin hole (for alignment) Pin hole (for alignment) HDI Connectors for extension cables Detector FPHX Chips Screw (nylon) (All bonds use rigid epoxies) HDI Sensor FPHX chips Backplane Rigid, thermally conductive epoxy Rigid epoxy

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 5 Half-Station Sub-Assembly Conductive silicone bond (for heat transfer) HDI Sensor FPHX chip Screw Pin Support Tab Support Panel Support Tab Low-mounted module High-mounted module Not enough space if modules side by side

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 6 Cooling and Support Tab Detail Screw hole (mounting to cage) Pin (alignment to cage) Hose barb for coolant (back side) Screw (holds wedge on disk) Silicon detectors, HDIs, and back-planes made transparent for clarity Pin (aligns wedge on disk) FPHX chip Built-in cooling tube Silicone heat transfer interface (RT-cured, conductive silicone) Sensor CC (TBC) heat transfer bridge

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 7 Support Panel Construction Locating pin Insert for pin (TBD plastic) Insert for screw (TBD plastic) GFRP Face sheet (0.25mm) Honeycomb core (4.76mm, 32 kg/m 3 ) Foam core (TBD mat’l) Core insert for pins and screws (TBD plastic) Cooling tube Hose barb GFRP Face sheet (0.25mm) Standoff plate (TBD Plastic) Mounting tab

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 8 Half Cage Sub-Assembly Cooling hose (silicone) Station 1Station 2Station 3Station 4 Z Y

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 9 FVTX–VTX Interference / Space Allocation VTX Strip Layer (#4) VTX Strip Layer (#3) VTX Pixel Layer (#2) VTX Pixel Layer (#1) Interference! (Wrap FVTX cage behind station 1 Reduce radius of station 1 Possibly move VTX4 out 1cm) FVTX Station 1FVTX Station 2 FVTX Station 3 FVTX Station 4

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 10 Radiation Length Status (1/2) Total RL of Station 2, 3, or 4 (normal incidence) –Area averaged to active area (45mm IR, 170mm OR) = 2.41%

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 11 Radiation Length Status (2/2) Local RL of Station 2, 3, or 4 (normal incidence) –Local extremes range from 1.8% to 9.1% Local values of %RL at normal incidence

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 12 Cooling System Keep FVTX near Room Temperature –Gas enclosure also at room temperature Power Dissipation –8W per half disk (stations #2, 3, 4) Cooling Tube Embedded in 3/16” Support Panel –Square cross section (3/16” by 3/16”) with super-thin (<50μm) nickel wall –Vendor currently under contract for trial fabrication of tube (~ 4 weeks) Coolant –3M Novec HFE-7000 –Completely harmless to (even live) micro-electronics –Environmentally friendly –Dense (1.4 × water) Flow Regime –Single phase –Strongly turbulent Re ~ 10,000 Flow velocity ~ 0.7 m/sec Flow rate ~ 20 g/sec = 14 gallons/hour (per ½ cage) –Flow-induced vibrations? Need testing

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 13 Wedge Analysis Temperature Contour Max Tº = 19.3ºC Warmest FPHX Min Tº = 15ºC (Boundary condition at back side of backplane) Temperature (°C) Warmest FPHX is 4.3ºC Warmer than Back Edge of Backplane –9.3ºC warmer than coolant Thermal stresses are very low –Rigid adhesives are fine Cooling-induced Distortions (assembled at room temperature) Deflection (m) Max deflection 8.1μm

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 14 Coolant to ROC Thermal Path Use Simple Correlations to Evaluate –Pressure drops –Temperature drop from fluid to cooling tube Approximate temperatures with 10°C coolant flowing at Re~10,000 (0.76mm K13CU backplane, 50μm Nickel tube, 0.2 W/mK epoxy, 0.75 W/mK silicone)

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 15 Liquid Cooling Circuit Run 4 Half-disks in Series

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 16 Station- and Cage-Level Modeling Fundamental Vibration ModeDistortion due to Cooling (assembled at room temperature) Max deflection ~ 21μm Max deflection within active area ~ 8μm 138Hz

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 17 Conclusions We have a fairly detailed preliminary design –But not a final design; detailing and some material selections pending Meets key requirements –Dimensional stability –Stiffness –RL Some remaining questions and issues –See next slides More work needed before fabrication phase –See next slides for details –Evolve design (following VTX and system-level evolution) –Resolve pending design issues –Prototype & Test Our FVTX design contract is now closed –No FVTX funding at this time Funding request in place with BNL for R&D funding –Cover minimal manpower level & prototypes through end of CY –What are our chances of getting funded? When?

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 18 Remaining Technical Issues Flow-induced vibrations: –Must insure that vibration level from turbulent flow is low Requires testing Support and cooling of sensor modules at edges of stations –Sensor modules at separation plane (6 and 12 o’clock) are insufficiently cooled and could use better mechanical support HDI tails tool long for Station 4 –Little space available downstream of station 4, within space allocation –Requires tight bend radius –Connectors/backing plate are in the way VTX/FVTX Interference –Solutions have been identified –Will be implemented as soon as funding is available

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 19 Future Work: Before Construction Phase Short-term (before construction phase) –System Design (shared with / largely funded by VTX) Gas enclosure “Big wheel” Routing and support of utilities Initial alignment / surveying approach Other –Effect of radiation on coolant (exposure tests) –Effect of coolant on materials (exposure tests) –Continue evolving FVTX design –Prototyping See next slide Construction phase –Grounding –Final material selections –Detailed design and fabrication drawings

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 20 Prototyping Main focus of R&D funding request Sensor module prototypes –GFRP backplanes + dummy HDI + dummy sensor + resistive heaters –Used to Test assembly tooling Thermal cycling (stresses in bonds and SSD) Heat transfer testing Validate temperature induced deflections (TV Holography?) – insufficient funding Half-Station prototype –One half disk (large) Supported by dummy structure (no cage) Populated with dummy detector modules –Used to Test manufacturing, assembly, and alignment concepts Measure flow induced vibration Heat transfer tests Half-cage prototype –Experiment with manufacturing approach –Double-duty as iFVTX support cage

HPS – FVTX Mechanical/Thermal Design – May 2, 2007 – Slide 21 Program Management Transition Eric Ponslet is leaving HYTEC –Effective May 17 –Personal reasons: going climbing… RJ Ponchione taking over PM role for PHENIX activities at HYTEC –Outstanding design engineer & quick learner –Rest of team remains unchanged: Shahriar Setoodeh: analytical design and simulation Vince Stephens: composite material expertise, PM assistance Roger Smith: CAD modeling and packaging Transition phase in progress –Immediate priority is VTX (stave prototypes) –iFVTX work continues as required –No FVTX funding at this point