Summary: Mechanics - Overview of the MFT in ALICE. - Description of the MFT. - Description of a MFT...

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Transcript of Summary: Mechanics - Overview of the MFT in ALICE. - Description of the MFT. - Description of a MFT...

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Mechanics Overview of the MFT in ALICE. Description of the MFT. Description of a MFT detection plane. Environment of the MFT. Procedure and tools for MFT installation. Conclusion, discussion

Cooling Thermal and fluidic studies on the MFT. Preliminaries studies of the impact of cooling on the MFT barrel.

Next steps

MFT WG7Mechanics and cooling ITS-MFT common week 10-13 March 2014 11


MFTThe place of the MFT in ALICEcross section at the beginning of the project (11/2011)beam

MFTITSabsorberBeam pipeIPTPCV0, T0, FIT?C sideA sideDisclaimer: the following presentation is mainly based on the MFT LoIwith some modifications: 6th plane added, planes position versus IP modified2

FITMFT barrelCage fixeBeam pipeBeam pipe supportService roomGeneral view of the MFT in ALICESketch of integration MFT-ITS-FIT-BPrelease MFT 11/2013Version TDR 6 ITS, BP od 19.8 mm

MFTMFTAbsorberITS3MFT coneMFT diskThe dimensions of the beam pipe are crucial for us.They need to be fixed as soon as possible, od 19 mm will be better for MFT


MFTMFT description. LoI release6 detection planes2 sealed half cone (up et down), (almost) symmetric

coneDetection planeBP* gutter*BP : Beam PipeBP support gutterFront diskRear diskKapton sheetRoom needed for the BP support4


Disk 0Disk 1Disk 2Disk 3Disk 4Disk 5IP768569688531493455Proposed distances between each disc and the IPIn accordance with ICD_20140207_MFT_vs_BP-1.ppt and related documents

5D 43.6D 50.4D 54.4D 60.4D 70D 64D 72Diameters values are diameter of the beam pipe or bellow plus safety room of 4 mm given by CERN.


MFTMFTs detection plan descriptionPlan type 04

Beam pipe passageDetection ladderAir cooling nozzleAir inletAir outletOptical fiber6


MFTMFTs detection plan descriptionSpilt view of the plan 04Objects constituting a planFront detection areaRear detection areaLadder supportpcbOptical transceiversAir cooling nozzle7


MFTMFTs detection plan descriptionTechnical proposal for a diskPCBFront detection areaRear detection areaLadder supportLadder supportladders8

MFTHere are the possible sizes of the various zones of every disks

Disc 0 to 3Disc 4 and 520D1D2D3PCB areadetection areammDisc 0Disc 1Disc 2Disc 3Disc 4Disc 5D1380400420440520560D2192200209221260286D349.649.649.660.47078D2 and D3 obtain according to the 3 and 9.4 angles, D1 defined according to ITS positionD3 values defined by adding a conservative safety room of 6 mm (2x3mm) for integration of the MFTs ladders. (less than 2 mm expected).

preliminary data9


MFTMFTs detection plane and ladder descriptionListing of plane component and power consumption for a half MFT10 * 954 sensors @ 325 mW/ASIC => 310 W

* 75 GBT @ 2.5W/GBT => 190 W

* 52 W for optic transceiver

* 252 W for DC-DC converters

about 800 W for a half MFT

C. Renard and S. Bouvier, 19/02/2014

sensorsflexConnector (PCB side)Connector (flex side)stiffener3 sensors ladder


MFTMFT environment

11Beam PipeBP Supportfixe cageC side BP supportwing of the BP supportRemovables rails11


MFTInstallation tools, MFT downAfter the assembly of the MFT detector:MFT mounted on the MFT barrel

12MFT barrelThe half MFT complete is installed inside the MFT barrel.All the services will pass through the MFT barrel, with an exit on the C side.

A sideC sideRoom for optical fiberZone de fixation FIT12


MFT Installation tools, MFT down barrel

Room for electrical and optical servicesMFT fixing areaPassage air/water coolingInlet and outletSketch of the MFT barrelFit fixing area



MFTProcedure and tooling for MFT installation14Insertion of the assembly (MFT, FIT, MFT barrel)

The MFT and its barrel are mounted around the BP,then the assembly is translated along the BP (Y, YZ).

The MFT barrel will move along slider installed on the fixe cage.Fixation of the assembly will be made at the end of the sliding movement.

The same procedure will be made with the MFT up.along Yalong YZ14


MFTProcedure and tooling for MFT installationITS, TPC,

ITS outer and middle layers

ITS inner layers

Rails extractionInternal TPC cage 15


MFTConclusion et discussionArea to be studiedQuestions and interface discussions

Beam pipe dimension need to be fixedOd 19 mm? but also the other od and the BP support?

ITS TDR need to be fixed* Extremity close to MFT of the middle layer* Room needed for MFT services

FIT* Mounted on the MFT barrel, ok* Fully independent from MFT, okbut* Now updated dimensions needed* Design of MFT barrel need information about FITs services

middle et outer layersEnvelope (TDR6)Modification proposalXX




Mechanics Overview of the MFT in ALICE. Description of the MFT. Description of a plan of the MFT. Environment of the MFT. Procedure and tooling for MFT installation. Conclusion, discussion

Cooling Thermal and fluidic studies on the MFT. Preliminaries studies of the impact of cooling on the MFT barrel.

Next step

The estimated model is in accordance with that presented in the LoI (power, geometry), the power coming from the read out is not counted, the change of the geometry of the disk due to BP support and its wing is not taken into account.

Several estimated models, with various materials for the disk supports (TPG, Beryllium, composites), with various modes of cooling (conductive and convective).

Conclusion, first proposal Use of an airflow at room temperature to cool detection planes, on surface and inside the planes. - Simplify the design, simplifies constraints. - allows to limit the quantity of material used (lowering X0).

Proposal of the use of Beryllium for the planes material, good ratio rigidity, X0, thermal conductivity (LoI).Composite cabon/epoxy work also, less costly than Beryllium

MFTAbstract of the MFTs preliminary thermal studies

1,4 mm2 mmFull diskoutsideoutsideinside3 distincts air flux

Air outletAir inlet18

Air 1Air 2Air 3Air 4Air 5Air 6Beam pipeParticulesDetection areaExample of simulation of air flow in the MFT

Air speeds inside the MFT are lower than 10 m/s

Average wall heat transfer are::

50 W/m.K outside the planes

30 W/mK inside the planes




Simple geometry, goal was to test several material and kind of cooling.

ASICinsulationflexsupportASIC:0,18mLength 30 mm, width 8 mm(5 mm active, 3 mm passive)thickness 50mpower deposit: 515 mW/sensor (LoI)Very conservative, actual value is: 325 mW/sensors

Flex: 2 x 57 m aluminum

Insulation: 3 x 50m de Kapton

Support/stiffener: 0,2 mm, Beryllium

convectionWater coolingPower deposit


convectionconvectionExample of thermal simulation of a ASIC group20


Quarter plan description (LoI):13 ladder1 ladder with 1 sensor1 ladder with 2 sensors6 ladders with 3 sensors5 ladders with 4 sensors

41 sensors for the studied quarter plan, about 328 sensors for the full disk (2 plans, recto and verso).

Power deposit on sensor is 515 mW. About 169 w for the full disk.Maximal air flow speed inferior at 10m/s.Wall heat transfer upside the sensors is 40 W/m.KWall heat transfer inside the plan is 25W/m.KAir flow temperature is 22C

Calculated maximum temperature of the ASIC is about 30C.

Thermal simulation on one MFT disk21

MFTThe use of the air at room temperature with a air flow speed lower than 10 m/s on the detection planes allows to obtain temperatures of functioning of the ASIC lower than 30 C,

1/ first cost estimate (170 k) concerning the manufacturing of support disk in Beryllium is too high, the use of composites Carbone-Epoxy should be favored. The Alloy AlBeMet could be an interesting candidate also (46 k). Good to know that the use of one of these three materials cheek few on the results.

2/ assure the cooling of the complete MFT with only of a air flow is not a unique, definitive or settled solution; the final amount of total powers dissipated in the plans as well as other considerations (of geometry, mechanical design) will make that we can be brought to complete the air cooling by a liquid cooling, in the area located out of the zone of detection in particular.In addition, the front end electronic on the PCB will maybe need to be water cooled.

3/ The previous simulation have been made with sensor power consumption of 515mW/sensor, nowthe sensors power deposit last value is 325mW/sensor. This reduction of the power will allow to reduce the speed ofthe air flow, and/or suppress the air cooling inside plan (simplification of the mechanical design).

First conclusion

22Quick estimate of the amount of cooling water to put in the " MFT Barrel "

P = dm*Cp*DT

hypothesis:P = power = 1.6 kW/2 = 800 W = 0.8J/s dm = mass flow rate (kg/s) Cp = heat capacity= 4.2 kJ/kW*K DT = delta T= 3 K 0.8 = dm*4.2*3 dm = 0.063 kg/s roughly 0.06litres/s = 0,06.10-3 m3

Ill take a velocity of 1m/s in order to limit the pressure loss along the pipes.

0,06.10-3/1 = 0,6.10-4 m make 60 mm, the cross section of 8.74 mm diameter pipe, round off at 9mm.

So we have a 9 mm inlet pipe and a 9 mm outlet pipe for each half MFT, that is to say two 9 mm diameter pipe per MFT barrel.

If we want smaller pipe we will mul