Philippe Grenier (CERN) ATLAS week, CERN October 2001 Cooling performances and tests during the...

ATLAS week, CERN October 2001Philippe Grenier (CERN)

Cooling performances and testsduring the September 2001 calibration period

Fernando Varela / Philippe Grenier (CERN)

ATLAS week, CERN October 2001


Cooling system in H8

water tank

output pipes

fridge unit

control box

return pipes


Monitoring of the cooling system

cooling unit informations (ELMBs)

- input/output temp on each drawer- water output temp

- water flow

drawer informations (HV program)

- also, HV on the PMTs- 7 temp probes located in the drawers

Monitoring PVSSII application Database (web interface)


Low voltages control

Drawer temperatures trends

PMTs HVs


Stability of the systemnormal working conditions: T=18 oC, Flow=60 l/h


Stability of the system during data taking

Tout<Mod2>=19.70.1 oC<Mod5>=19.60.1 oC

<Mod2>=18.30.1 oC<Mod5>=18.40.1 oC

<Cooling>=18.30.1 oC

Tin


Increase of the water temperature in the drawers

(oC)(oC)


Stability of the temperature inside drawer


Cooling tests

1- variation of the water input temperature (16 oC 22 oC)

(180 GeV electrons shooting in cell A14)

PMT gain variation measured with particules

drawer temperatures variations

2- variation of the water flow (10 l/h 60 l/h)

drawer temperatures variations


Water flow variationsCooling Temperature = 18 oC

optimal flow: 60 l/h


Drawer temperatures variationsFlow = 60 l/h

6 oC3 oC

T(PMT) = 1/2 T(cooling)


PMT gain variation versus temperature

E/E = 0.2 % / oC(PMT) E/E = 0.1 % / oC(cooling)

resolution

total energy deposited versus temperature in PMT#22180 GeV electrons


Conclusions

- optimal flow: 60 l/h (without LV in fingers)

- T(output - input) = 1.3 oC, for a flow of 60l/h

- Gain(PMT) = 0.2% / oC(PMT) = 0.1% / oC(cooling)

- cooling water temperature stability: 18.3 0.1 oC


Still to be done

- Effect of room temperature variation with non-isolated pipes (using foreseen tubes)

- ( not yet operating: cooling unit for Cs calibration in blg 185 ready)

- Next year: re-optimize flow with finger LV power supplies

- Pilot Project (see next slide)


Cooling pilot project in blg 185

- budget approved last week (50% financed by EP div JCOV committee)

- real size test (ATLAS): note

- Schedule (Sept 2001 - Sept 2002):- 15m high scaffolding available- components just ordered- start mounting/piping , until end of the year- tests to be done: Jan 02 Sept 02


Cooling pilot project in blg 185: Scaffolding installation

Philippe Grenier (CERN) ATLAS week, CERN October 2001 Cooling performances and tests during the...

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