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

Vacuum Vessel Models

• Cylindrical Model

• Rectangular Model

C. Newsom November 12, 2001

Cylindrical Model

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

Vacuum Interface 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

Temperature Results

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

MCM Vacuum Test Vessel

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

C. Newsom November 12, 2001

Neutron Activation

• Will modify an 80gram Pu/Be neutron source for activation studies

• Source is available indefinately

• Must test all materials and the products used to clean them!