November 16, 2001 C. Newsom BTeV Pixel Modeling, Prototyping and Testing C. Newsom University of Iowa

November 16, 2001 C. Newsom Overview Pixel Vessel & Internal support structures Vacuum Interface Board HDI/Flex Cable tests Pixel Support Module prototypes Materials testing Summary

November 16, 2001 C. Newsom Pixel Vessel and Internal Support Structures Rectangular Model-Integrated Carbon Manifold Carbon Fiber Half Barrel Structure

November 16, 2001 C. Newsom Rectangular Model Integrated Carbon Manifold The Pixel Support Modules mount directly on the carbon manifold Pure carbon joints are not sufficiently robust and need more research Manifold to Chip Module connections unsolved.

November 16, 2001 C. Newsom Carbon Fiber Half-Barrel Design Barrel is double walled laminated carbon fiber. Cables are moved to a side board. Space at bottom now available for motion, pump structures Insufficient space for HDI/daughter boards shown here. Major assembly problems

November 16, 2001 C. Newsom Vacuum Interface Board Carry ~35,000 signals from inside to outside the vacuum Constructed from 6 separate boards each with its own o-ring. Daughter cards have been removed to gain space. Ribbon cables pass through the surface and plug into the back side. Should we join the 6 boards, build a single board, …?

November 16, 2001 C. Newsom Vacuum Interface Board

November 16, 2001 C. Newsom HDI/Ribbon Cable Flexor One end is at -10C, and one at 25C to cool the power lines. Must absorb 2cm motion of half barrel during tuning. The cable must work in a vacuum.

November 16, 2001 C. Newsom Pixel Support Module Prototypes Fuzzy carbon prototypes –Initial Design –Improved Carbon Joints –Current Design Beryllium prototypes –Aluminum Modules (serpentine flow) –Aluminum Modules (parallel flow) –Stainless Steel Module (parallel flow)

November 16, 2001 C. Newsom Fuzzy Carbon Prototypes Thermal Prototype Mechanical Prototype Current Status

November 16, 2001 C. Newsom First Fuzzy Carbon Prototype Temperature drop of ~7 degrees (ok) Mechanically very weak Manifold joint failures

November 16, 2001 C. Newsom Mechanical Prototype This module looks very similar to the first prototype It differs in that the fibers are more randomized so that cross connects can strengthen the coupon Additional reinforcement at ends was added The module was considerably stronger but additional effort is needed Coupon still has joint problems

November 16, 2001 C. Newsom Carbon Carbon Joint Efforts Note effects due to 20% shrinkage Nanotubes added to increase joint strength Still much weaker than conventional epoxy

November 16, 2001 C. Newsom Ovalized Joined Tubing Original DesignOvalized Design Ovalized Glassy Carbon Tube Array

November 16, 2001 C. Newsom Future Fuzzy Ovalized Carbon Modules Ovalized tubing provides thinner cross section Fibers connect more directly to the coolant tubes giving much better heat transfer Connected carbon tubes are considerably stronger The manifold joints clearly need more R&D

November 16, 2001 C. Newsom “Beryllium” Prototype Modules Serpentine flow 2mm channel (aluminum) Parallel flow 2mm channel (aluminum) Parallel flow 0.5mm channel (stainless steel)

November 16, 2001 C. Newsom Prototype Flow Test Results Parallel Channel Al Module Parallel Channel SS Module

November 16, 2001 C. Newsom Thermal Test Setup Measure temperatures using RTD sensors Heat both surfaces with brass heat spreaders on silicon wafers. Variable flow and heat input A vacuum chamber will also be used in future tests

November 16, 2001 C. Newsom Aluminum Module Heat Tests Heating curves at nominal 0.5W/cm2, both sides One liter/min flow

November 16, 2001 C. Newsom Temperature Results

November 16, 2001 C. Newsom Vibration Tests Vibrations perpendicular to the surface. Vibration vs flow from 0 to 1.5L/min Corrected for external vibrations All motions are below 1 micron

November 16, 2001 C. Newsom Pixel Support Module Summary We are on track to a workable solution We are optimistic that this technology will work. This remains our baseline design We are moving toward workable solutions The Si/Be CTE problem is being studied This is a fall-back solution Fuzzy Carbon Beryllium

November 16, 2001 C. Newsom Materials Testing Stress and strain effects Vacuum effects Neutron activation Radiation Damage What should we be worrying about?

November 16, 2001 C. Newsom Sound is a pulse with most components in the 1MHz range. Young’s Modulus Apparatus

November 16, 2001 C. Newsom Epoxy Study Can measure speed of sound to 0.5% from a single measurement. From speed of sound, we can know Young’s modulus Will measure before/after effects of radiation, stresses, etc.

November 16, 2001 C. Newsom Conclusions We have made significant advances in many areas, solving many problems Integration issues are now being studied and solutions incorporated into the baseline design Many design parameters are much better understood There is a lot of remaining work to be done!