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PIXEL Detector Integration mechanical requirements

H. WiemanChristie Integration meeting16-May-2008

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topics

Introduction – parameters and requirements cooling system

space power heat load to wide angle hall

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Pixel detector function

Topological D meson reconstruction

Requires high precision vertex pointing

Critical parameters: very thin, low X/X0 very close to the

interaction point

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Pixel geometry

2.5 cm radius

8 cm radius

Inner layer

Outer layer

End view

One of two half cylinders

20 cm

coverage +-1

total 40 ladders

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Some pixel features and specifications

Pointing resolution (13 19GeV/pc) mLayers Layer 1 at 2.5 cm radius

Layer 2 at 8 cm radiusPixel size 18.4 m X 18.4 m Hit resolution 10 m rmsPosition stability 6 m (20 m envelope)Radiation thickness per layer

X/X0 = 0.28%

Number of pixels 436 M

Integration time (affects pileup) 0.2 msRadiation tolerance 300 kRadRapid installation and replacement to cover rad damage and other detector failure

Installation and reproducible positioning in a shift

criticalanddifficult

(ALICE Pixels 0.9%)

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Pixel air cooling system

Internal duct 2 in diameter X 5 ft

Internal duct 2 in diameter X 5 ft

external duct 6 in diameter X 50 ft

external duct 6 in diameter X 50 ft

chiller

pump

Wide angle hall ISC

Air flow: 400 SCFM

Total pressure drop: 22 inches water

Temperature: 75 deg F/34 deg C or maybe -10 deg C

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Pixel heat load break down

Heat source Power (watts)

detector silicon 160

on ladder signal drivers 80

voltage regulators in ISC 24

heat influx through ducting and ISC if 35 deg C below ambient

600 - 2000

pumping 1000

Total load on chiller 1900 - 3300

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Pump

5 HP motor

11 in 18 in

25 in

Air flow: 400 SCFM (300 SCFM maybe sufficient)

Total pressure drop: 22 inches water

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Chiller

Unit to be investigated Requirements:

2 – 3 kW Temperature: 75 deg F/24 deg C or -10 deg C ? flow 300-400 SCFM

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Infrastructure power load

Heat load to the hall: Up to 2-6 kW if all dumped to air Much less if chiller is cooled by chilled water or has compressor

and radiator outside

AC power: 2-6kW Chilled water: 2-6kW if used