Thermo-mechanical activities at Valencia

V. Castillo, C. Lacasta, A. Oyanguren, P. Ruiz

8th International Workshop on DEPFET Detectors and applications

(IFIC - Valencia)

21/9/2011

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Outline

8th International Workshop on DEPFET Detectors and Applications

Mock-up status at VLC

Studies of air flow cooling:- Effect of CO2 cooling + air flow at several temperatures on the ladders

Conclusions Plans at VLC

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Mock-up

COCO22 open open systemsystem NitrogenNitrogen

liquid Dewarliquid Dewar(cooled air)(cooled air)

Thermally Thermally isolated boxisolated boxwith dry atmospherewith dry atmosphere

chillerchiller

IR cameraIR camera

Mock-upMock-up

8th International Workshop on DEPFET Detectors and Applications

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Mock-up

Mock-up status:

- Mechanical dummy temporarily fixed in the CrCo sample: (plastic nut + screw ended with a wire embedded in the hole)- Thermal grease for the thermal contact- One resistor sample in the outer layer

- Set voltages: Sensor: 12 V P ~ 1W Switchers: 3V P ~ 0.25 W DCDs/DHPs: 20V P ~2.5 W

It works!(appart from the left switchers)

8th International Workshop on DEPFET Detectors and Applications

Mock-up

Calibration tool for the IR camera: ( depends on the material)

KaptonCu

Al

sensor

DCD/DHP DCD/

DHP

switcher

(broken) mechanical dummy

Tipp-ex

greaseTape 2

Tape 1

Marker

Al box filled with coolant: cooled down with chiller, heated with heaters. Study material

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~ 0.65

~ 0.35

~ 0.18

T= 90ºC

T= -10ºC

8th International Workshop on DEPFET Detectors and Applications

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Air flow studies

- Effect of blowing air at room temperature:

-The air flow (at room T) decreases and homogenizes the temperature along the detector. Decreases T ~ 15 C Max T along the ladder 18C 8C

Camera position

DCD/DHP

DCD/DHP

(corrected emmisivity)DCD/DHP

DCD/DHP

8th International Workshop on DEPFET Detectors and Applications

(vair (inlet) ~ 2m/s)

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Air flow studies

- Cooling down the end flanges with CO2

- Blowing air/N2 at different temperatures (cooled down with N2 liquid atmosphere)

Camera position

T (

ºC)

(corrected emmisivity)

25 ºC

- Bumps ?? (crab legs)- With CO2 + air flow T along the ladder ~ 20ºC (!?)

- Detector on: T ~ 45ºC- Effect of CO2 + air flow : T ~ 20ºC (or below)

Looking at the central region of the sensor:

Looking at the edges:

8th International Workshop on DEPFET Detectors and Applications

(vair (inlet) ~ 2m/s)

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Air flow studies

- Problems of IR transparence due to the thickness of the detector:

left switchers off

(corrected emmisivity)

sensor

switchers

- sensor- switchers

- Tipp-ex marks behind in the Cu inner ladder

Present setup

Previous setup

Tipp-ex marks behind

End flanges

Camera position

T(º

C)

Detector on, CO2 in the end flanges, no air flow

End flanges

Sensor and switchers: expected about same and behaviour

8th International Workshop on DEPFET Detectors and Applications

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Air flow studies

- sensor- switchers

(corrected emmisivity)

- Detector on, CO2 in the endflanges, cooled air flow

Effect of a polycarbonate sheet (IR opaque) behind the mechanical dummy (i.e. between the inner and outer ladders:

A few degrees (~3) difference, not observed for the switchers region, due to the reflexion in the inner ladder, seen by the IR camera through the thick sensor.

Effect of IR transparence due to the thickness of the sensor (?)

T~10ºC

8th International Workshop on DEPFET Detectors and Applications

Camera position

T(º

C)

Arantza Oyanguren 108th International Workshop on DEPFET Detectors and Applications

- More realistic conditions for the detector, set voltages so: Sensor: P ~ 0.5W Switchers: P ~ 0.5W DCDs/DHPs: P ~ 8W

- Inner cupper ladder covered with a polycarbonate dummy, opaque to IR

Camera positionT

(ºC

)(corrected emmisivity)

Sensor

Detector onBackground (room T)

End flanges cooled with CO2

Air flow at room T

Air/N2 flow cooled [-8,-15]C

C. Mariñas simulationAir flow studies

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- Sensor region (P~0.5W):

8th International Workshop on DEPFET Detectors and Applications

- Temperature for the sensor when switching on the detector: ~ 60 C- Cooling the endflanges (CO2): T sensor< 25 C (~ room T to check colder environment)- Blowing air at room T T sensor < 20 C and homogenus - Blowing cooled air (-8,-15) C T sensor < 15 C and homogeneus - Tmax along the sensor ~ 10 C (contact + remaining transparence)- For a proper T estimation from the enflanges one should have all detectors on (but should be ok following the Karlsruhe test

(see next page))

Camera position

T (

ºC)

Sensor Detector onBackground (room T)

End flanges cooled with CO2

Air flow at room T

Air/N2 flow cooled [-8,-15]C

Air flow studies

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From Karlsruhe (S. Heindl, Feb 2011) :

Silicon pieces with resistors (20W each) 120W + CO2 Cooling: Endflange at < -10 C (most probes)

PT1000s

8th International Workshop on DEPFET Detectors and Applications

Air flow studies

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- Switchers region (P~0.5W):

8th International Workshop on DEPFET Detectors and Applications

- Only right switcher was operating - Temperature for the switchers when the detector is switched on ~ 40 C- Cooling the endflanges (CO2): T sensor ~ 20-30 C (room T to check colder environm.)- Blowing air at room T T sensor < 25 C and homogenus - Blowing cooled air (-8,-15) C T sensor < 25 C and homogeneus - Small Tmax along the detector < 10 C

Camera position

T (

ºC)

Detector onBackground (room T)

End flanges cooled with CO2

Air flow at room T

Air/N2 flow cooled [-8,-15]C

Switchers

(corrected emmisivity)

Air flow studies

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Conclusions

- Valencia mockup set up and understood.

- At present, all tests show:

Cooled air flow decreases the ladder temperature below ~20C

Tmax along the ladder less or around 10C

- Valencia activity on thermo-mechanical issues will smoothly decrease in the

next year, but at present this setup may be used for any envisaged thermal test

In particular:

8th International Workshop on DEPFET Detectors and Applications

1.5m pipe coil at the CO2 return to cool down the air:Air flow temperature in the outlet ~ -5 - 0 C

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Mock-up

Until now, air or N2 gaseous cooled by the atmosphere inside the liquid N2 Dewar (-80C) New CO2 exchanged system to cool down the air flow:

8th International Workshop on DEPFET Detectors and Applications

- Test air flow cooling with the CO2 return

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Plans

Al samples

Carbon fibers

8th International Workshop on DEPFET Detectors and Applications

- Test air flow effect in the inner ladders (mainly for the switchers) through carbon fibers

- Set up the new endflanges of aluminium and/or stainless steel (ladders better screwed, better fixed and better thermal contact)

Arantza Oyanguren 8th International Workshop on DEPFET Detectors and Applications

Capacitive Non-Contact Displacement detectors:

ATLAS setup

- Test possible vibrations in the detectors due to the air flow

Plans

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Dummy ladders:

Heaters

Polycarbonate

Al

Cu

Backup

Resistor samples

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Backup

Air flow

20

22

24

26

28

30

32

34

36

0 0,5 1 1,5 2 2,5 3 3,5

Air v (m/s)

T (

ºC)

Inne ladder

Outer ladder

Cooling block

Effect of air velocity

- It is enough to have a very low speed flow air to achieve a proper heat dissipation in the ladder (1WT~ 6-7ºC),

(Expected behaviour from Carlos simulations)

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Inner ladder:

Backup

heaters (3W)

CO2, No air flow

Air flow T~0C*

* entering in the box; T in the CB?

Air flow T~-20C *

Camera positionT

(C

)