ALICE PRR TRD COOLING P.Gl

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ALICE PRR TRD COOLINGP.Glässel,
A.Marín, V.Petracek, J.Stachel, M.R.Stockmeier,
J.P.Wessels
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PRR of the TRD Cooling

• The TRD detector in ALICE
• Cooling plant
• Heat generated by the detector
• Map of heat sources
• Routing of pipes
• Test measurements
• Construction and tests during assembly
• List of materials used

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The TRD detector in ALICE

• 18 SuperModules in f
• 30 chambers/SM in 6 layers
• 6/8 Readout Boards/ chamber
• 16 MCMs/RB
• 1.18x106 channels

TRD
RB24
RB26
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Readout Board in a chamber
Test room
MCMs
Readout board
TRD chamber
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Map of heat sources in TRD
Readout board
Stack of chambers
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Heat sources in TRD (I)
Source Power (W) Amount Total Amount (SM) Total Power per SM (W)
0 (VR) 0.21 2/RB 456 96
1 (VR) 0.88 2/RB 456 401
2 (VR) 0.066 2/RB 456 30
3 (VR) 0.352 2/RB 456 161
4 (VR) 0.009 1/RB 228 2
5 (VR) 0.044 1/RB 228 10
6 (MCM) 0.52 16/RB 3648 1897
7 (DCS) 5 1/chamber 30 150
8 (bars) 16 2/layer 12 192
The total dissipated power is 53kW
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The TRD cooling plant (CERN-ST/CV)

• 18 cooling circuits (1/SM)
• Inlet RB26/ Outlet RB24

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The TRD cooling plant (CERN-ST/CV)

• Flow rate
• TRD 18? 1.5m3/h
• Total flow 27 m3/h
• Total heat to be removed 55kW
• Total Volume of water in the installation 2000L
• Range of available water temperature at the
  Heaters outlet
• Super-modules 1618ºC

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Routing of services inside SM
Power bars 16 W
Main water supply in each layer 250 l/h
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Voltage regulators (VR)

• Temperature in VR test board seen by IR camera
• No cooling is applied

1
3
1
3
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VR temperature profile (IR camera)
60 0 C reached without cooling
Size of VR6x3mm2
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Desing of Cooling Pads

• MCM 0.520 W
• 40x40x0.4 mm3 Al pad (minimize radiation length)
• 2(3) mm inner (outer) diameter Al pipe of length
  9 cm
• 3M heat conductive tape (9890,5506)

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Cooling meander

• Cooling circuit across f ( 456 per SM)
• Type A (0)8x(6)(0)(1) 5.45 W
• Type B (1)(2)(3)(4)(5)8x(6)(2)(3)
  (4)(5)5.9W
• Water flow 3.4 l/h
• DT1.50C

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Test cooling system, MCM

• Tap water
• Needle valve
• Pressure meter

Tin 14.60C
Tout 15.60C
Readout board
MCM
TMCM 21.30C 19.60C
20.50C
dTglob-top 4.10C 3.20C
4.40C
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Optimization VR
(a) (b)
dTVR1 8.50C /9.30C dTVR3
4.40C dTVR0 3.50C/5.40C
foam
(a) 2 Al pipes over VR
(b) 1/2 Al pipes over VR Heat bridges
1 Al pipes touching RB
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IR camera
2 Al pipes over VR
1/2 Al pipes over VR Heat bridges
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Long term test using VR setup

• Power dissipated 5.2W (equivalent to a cooling
  meander)
• All pipes in series
• Air gap 15 mm
• Good thermal insulation pipes, air volume
• Pipes touching VR (no heat bridges), pipe over RB
  in both sides

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Results of long term test

• DTwater out1.3-1.50C
• (expected 1.50C)
• DTair6.70C
• Tair stable over 4 days

Heat on
3.4-3 l/h
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DCS cooling test
Flash
VR
FPGA/EPXA1
TTCrx

• Pipes over main heat dissipation components

Tin 18.70C Tout 200C TVR1
33.70C TVR2 35.80C TTTCrx 33.70C TFPGA
36.80C Tair 290C
Ethernet
New DCS ,VR in parallel!
SDRAM
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Grounding scheme

• Cooling pipes along f electrically insulated from
  electronics (MCM) and Supermodule
• Cooling pipes along f can be electrically
  insulated from cooling pads or electrically
  connected
• To be decided based on noise measurements
• Possibility of connecting cooling pipes to RB (or
  SM) ground
• To be decided based on noise measurements

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Assembly and tests

1. Meander construction in a company
2. Measure pressure drop in each meander
3. Glue Al plates in each cooling meander.
   Electrically insulating material between pipe and
   plate if needed for noise requirements.
4. Put heat conductive tape on top of each component
5. Glue cooling meanders to RB in a flat table using
   Al-filled epoxy.
6. Inspect visually that all Al plates are touching
   the heat sources. Mark each checked component.
7. Power electronics and measure the temperature
   underneath each heat source using a plate
   equipped with Pt100 at given positions.
8. Check that all electronics is still working.
   Avoid damage during gluing
9. Position the RB preequipped with cooling meanders
   in the chambers. Connect the cooling meanders
   between the two RB and between RB and the main
   water supply using Viton connectors. Fix RB to
   chambers
10. Once every layer is fully equipped test for leak
    tightness by pumping with vacuum pump

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Material used

1. Al tube of 2(3) mm inner (outer) diameter.
2. Al plates of 40x40x0.4 mm3
3. 3M tape (5506,9890) for thermal conductivity and
   electrical isolation
4. Al powder and epoxy