november 12, 2001 c. newsom btev pixel modeling, prototyping and testing c. newsom university of...
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C. Newsom November 12, 2001
BTeV Pixel Modeling, Prototyping and
Testing
C. Newsom
University of Iowa
C. Newsom November 12, 2001
Overview
• Vacuum Vessel Models
• Internal support structures
• Vacuum Interconnect Board
• HDI/Flex Cable tests
• MultiChip Module prototypes
• Materials testing
C. Newsom November 12, 2001
Cylindrical Model
• Shown here are cables from both front and back sides of the pixel module.
• Side cables must twist, stressing the pixel module non-symmetrically.
• Insufficient space for side cables
C. Newsom November 12, 2001
Rectangular Model• Rectangular model has
more space for side cables
• Cannot plug cables into the sides since there is a magnet pole behind it.
• Cooling manifold interferes with horizontal cables from the back of the module.
C. Newsom November 12, 2001
Internal Support Structures
• Integrated carbon support/manifold
• Carbon Half Barrel Structure
C. Newsom November 12, 2001
Integrated Carbon Support/Manifold• The MultiChip
Modules mount directly on the carbon manifold
• Pure carbon joints are not robust and need more research
• Manifold to Chip Module connections unsolved.
C. Newsom November 12, 2001
Carbon Half Barrel Design• Barrel is double walled
laminated carbon.• 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
C. Newsom November 12, 2001
Vacuum Interconnect 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, …?
C. Newsom November 12, 2001
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.
C. Newsom November 12, 2001
MultiChip Module Prototypes
• Beryllium prototypes– Aluminum Modules (serpentine flow)– Aluminum Modules (parallel flow)– Stainless Steel Module (parallel flow)
• Fuzzy carbon prototypes– Initial Design– Improved Carbon Joints– Current Design
C. Newsom November 12, 2001
“Beryllium” Prototype Modules
Serpentine flow 2mm channel (aluminum)
Parallel flow 2mm channel (aluminum)
Parallel flow 0.5mm channel (stainless steel)
C. Newsom November 12, 2001
Prototype Flow Test Results
Coupon v3 channel flow position vs. time (0.2 L/min)
0
2
4
6
8
10
12
14
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
time(seconds)
12cm/s
17
1919
17 4.6
Parallel Channel Al Module
Parallel Channel SS Module
C. Newsom November 12, 2001
Thermal Test Setup
• Measure temperatures using RTD sensors
• Heat both surfaces with brass heat spreaders on silicon wafers.
• Variable flow and heat input
C. Newsom November 12, 2001
Aluminum Module Heat Tests
• Heating curves at nominal 0.5W/cm2, both sides
• One liter/min flow
C. Newsom November 12, 2001
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
C. Newsom November 12, 2001
Fuzzy Carbon Prototypes
• Thermal Prototype
• Mechanical Prototype
• Current Status
C. Newsom November 12, 2001
First Fuzzy Carbon Prototype
• Temperature drop of ~7 degrees (ok)• Mechanically very weak• Manifold joint failures
C. Newsom November 12, 2001
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
C. Newsom November 12, 2001
Carbon Carbon Joint Efforts
• Note effects due to 20% shrinkage
• Nanotubes added to increase joint strength
• Still much weaker than conventional epoxy
C. Newsom November 12, 2001
Ovalized Joined Tubing
Original Design Ovalized Design
Ovalized Glassy Carbon Tubes
C. Newsom November 12, 2001
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
C. Newsom November 12, 2001
Materials Testing
• Stress and strain effects
• Vacuum effects
• Neutron activation
• Radiation Damage
C. Newsom November 12, 2001
H2O
SourceReceiver Sample
Sound is a pulse with most components in the 1MHz range.
Young’s Modulus Apparatus
C. Newsom November 12, 2001
Epoxy Study
• Can measure speed of sound to 0.5%
• From speed of sound, we can know Young’s modulus
• Will measure before/after effects of radiation, stresses, etc.
4 Hour Epoxy
Velocity Studies
-0.15
-0.10
-0.05
0.00
0.05
0.10
0.15
0.00 5.00 10.00
Time ( μ )s
Water Signal
10 mm Epoxy
3 mm Epoxy
Initial Pulse
2H O
3mm10mm
T h ic k n e s s ( m m ) 3 . 2 4 5 . 1 7 6 9 . 3 7 3
T r a n s i t T im e ( ? s ) 0 . 8 5 1 . 3 5 2 . 7 2
V e l o c i t y ( m m / ? s ) 2 . 4 6 5 2 . 4 5 6 2 . 4 7 7
A v e r a g e 2 . 4 6 6 + / - 0 . 0 0 8
s t d e v 0 . 4 %
4 H o u r E p o x y