HFT PIXEL Mechanical Progress Strasbourg June-2009 Wieman 1

HFT PIXEL Mechanical Progress

Strasbourg

June-2009

Wieman

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Topics

• Thin support beam• ladder fabrication• Air cooling analysis• Air vibration tests• Full scale cooling

tests• Spatial mapping

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Development of sector beam and ladder fabrication

• Eric Anderssen and Tom Johnson have been working on fabrication methods for:– Sector Beam– and Ladders

• Produced sample beams, 244 m thick, 7 ply, 21 gm

• expected ladder mass 7.5 gm

ladders

sector beam

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prototype design being built

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PIXEL mass breakdown

Sector structures

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ladder fabrication and tooling

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ladder fabrication and tooling

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ladder fabrication and tooling

9finalizing mechanical designs and developing rapid production methods

ladder fabrication and tooling

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ladder withsilicon heaterchips(50 m thick)

wire bonding 50 m silicon to flex PC

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vacuum chuck tosecure flex and siliconflat against solid surfaceto remove bounce

Any bounce then no bond

Good Newsafter a couple of minor modifications to the vacuum chuck wire bonding works well

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ladder to sector bond fixture

ladder to out2 bond fixture.SLDASM

(designed to allow ladder replacement)

ladder to sector tooling fixtures (4 stations)

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Air cooling of silicon detectors – Computational Fluid Dynamics (CFD) analysis

air flow path – flows along both inside and outside surface of the sector

• Silicon power: 100 mW/cm2 (~ power of sunlight)

• 240 W total Si + drivers

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Air cooling – CFD analysis• air flow velocity 9-10 m/s• maximum temperature rise

above ambient: 12 deg C• sector beam surface –

important component to cooling

• dynamic pressure force 1.7 times gravity

stream lines with velocity

silicon surface temperature

velocity contours

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430 mm ID

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vibration modes – preliminary – better composite numbers available

229 Hz

316 Hz

224 Hz

473 Hz

348 Hz

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vibration modes with reinforced end cap

• The message– Lots of complicated modes close in

frequency– End cap raises frequencies a bit

259 Hz

397 Hz

276 Hz

441 Hz

497 Hz

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air velocity probetwo positions shown

capacitance vibration probetwo positions shown

carbon fiber sector beam

wind tunnel setup to test vibration and displacement

adjustablewall for airturn around

air in

air out

C:\Documents and Settings\Howard Wieman\My Documents\aps project\mechanical\PXL phase 1 sept 2008\sector ph1 wind tunnel.SLDASM

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wind tunnel, rapid prototype parts from model air flow control

parts built with3D printer

parts built with SLA, stereolithography apparatus

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wind tunnel

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capacitive probe vibration measurements

air velocity 2.7 m/s

position signal, 25 m/volt

air velocity 9.5 m/s

position signal, 25 m/volt

log FFT, peak at 135 Hz

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Ladder vibration induced by cooling air

30m

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20m

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system resolution limitall errors

desired vibration target

required air velocity18 mph

0 2 4 6 8 10 120

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4

6

8

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measured vibration with negative pressure modemeasured vibration with positive pressure mode

Ladder Vibration

air velocity (m/s)

vibr

atio

n R

MS

(m

icro

ns)

5.77

8.66

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Full sized cooling tests

Thermal camera window not shown

> 300 CFPM air flow for verification of cooling capability

Cooling tests will begin as soon as prototype sectors completed

9 inch diameter tube mocks upMSC

23dust collector for air supply

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development of spatial map procedureBob ConnorsSpiros MargetisYifei Zhang

touch probe 2-3 m (xyz) andvisual 2-3 m (xy) 50 m (z)

active volume: huge

10 gm touchprobe force(could deflect beam)

MEMOSTAR3, 30 m pitch

We need better fiducialson the main pad side that the coordinate machine can find automatically.

The pads will be buried and not visible