1 Energy Science Laboratories, Inc. Materials & Processing ESLI Cooled Carbon Support BTeV Pixel Detectors Development Recommendations for 2001 T R Knowles 3/7/01

2 Energy Science Laboratories, Inc. Materials & Processing ESLI FY00 Progress Cooled carbon structure demo articles (full-scale) –Lightweight –Rigid –Shingled surface –Porous chip mount –Al manifolds Issues –Resistance at tube wall is high Need to increase thermal conductance –Tubing cracked, leaked Need to increase toughness and assure leak-tightness Fibrous surface for shingling with high contact conductance Vertical high-k fibers with in-plane discrete fiber reinforcements Tubes cemented in grooves

3 Energy Science Laboratories, Inc. Materials & Processing ESLI Increase Thermal Conductance “Fintubing” Concept –Improved fiber orientation –Issues: Precision? Manifolds? “Tubewall” Concept –Complete layer of tubing Tubing height < 1 mm –Issues: Precision, Rigidity? Manifolds

4 Energy Science Laboratories, Inc. Materials & Processing ESLI Graphite Header Tubing Sealed POCO graphite tube –Tube machined from POCO –Pyrocarbon CVD seal coat Helium leak test –Light CVD seal reduced He permeation to <5e-9 mL/s (most sensitive scale on leak detector) –Expect heavier coat to seal even better (no helium leak signal) Good candidate for headers –May reinforce with carbon braid to improve strength and toughness POCO graphite rod CVD POCO tube, (unreinforced – 8 ksi)

5 Energy Science Laboratories, Inc. Materials & Processing ESLI Tube Manifolding Carbon carbon construction –Tubular elements Large-gauge headers Small-gauge lines –Carbon joining Carbonize bonding resin Seal by pyrocarbon CVD Reinforcement options –Integral boss on graphite header for larger tube/header interface –Fabric reinforcements

6 Energy Science Laboratories, Inc. Materials & Processing ESLI FY01 Task 1 Review Issues and Options THERMAL “fintube” and “tubewall” options –Fabricate small comparison articles STRUCTURALfibercore; carbon fiber frame –Fabricate small comparison articles MANIFOLDINGaluminum vs carbon –Fabricate carbon-carbon T-joint to test hermiticity TOUGHNESSreliable tube/manifold connection –Fabricate stress-relieved joints with velvet or fabric

7 Energy Science Laboratories, Inc. Materials & Processing ESLI FY01 Task 2 Fabricate Prototypes Fabricate two (2) Cooled-Carbon Supports –Incorporate design features selected from Task 1 Assure leak-tightness by monitoring throughout fabrication Mount on aluminum frames; attach inlet and outlet lines Preliminary heat exchanger performance test at ESLI –Measure flow impedance –Measure heat exchanger performance T heater - T coolant when symmetrically 1 W/cm 2

8 Energy Science Laboratories, Inc. Materials & Processing ESLI FY01 Task 3 Superstructure Options Work together with FNAL engineering to draft design of support superstructure based on –Lightweight sandwich structures –Carbon tubing –Carbon truss superstructures carbon rod space framebulkheads

9 Energy Science Laboratories, Inc. Materials & Processing ESLI Carbon Truss Structure Concept Carbon sheet (100 µm) bulkheads Carbon-fiber rods in tension Carbon tubing & manifolds Carbon fibercore thermal area

10 Energy Science Laboratories, Inc. Materials & Processing ESLI Cost/Schedule