University of AthensATLAS BIS

MDT assembly http://www.phys.uoa.gr/Atlas/MDT

HEP 2001 Presented byHeraklion, 6-8 April 2001 D. Fassouliotis

• D. Fassouliotis• P. Ioannou• C. Kourkoumelis• V. Pancheluga• D. Pappas• E. Stefanidis• V. Birioukov (engineer from Protvino)

Physics Requirements of ATLAS Muon Spectrometer

•Acceptance•Efficiency•Momentum Resolution

H μμμμ

SM/SUSY Higgs New Vector Bosons

B+ J/ψK+

Beauty PhysicsCP violation

OUR AIM:Wire/Wire/checkcheck all the Monitored all the MonitoredDrift Tubes for the ATLASDrift Tubes for the ATLASBIS chambersBIS chambers

30,000 !! Tubes – 128 chambers

With Construction specifications…:

Wire position ± 25 μmWire tension 350 ± 15 grGas leak rate < 10-8 bar*l/s at 3 barLeak at 3.4 kV (gain 1.6*105) < 2nA/mFinished tube length 1671.50 ± 0.25 mm

…necessary to achieve the physics results

TO ACCOMPLISH AIM:

Build a clean room•20±1 oC•Class 50,000

Develop a wiring table+wiring tools•Flat top•Tube holders•Alignment of two end-plug-holders•End-plug insertion (coaxility tube/end-plug)•Tube pressure crimping•Speed of wire threading•Wire tensioning

Develop on-line QA of tube construction parameters•Length check•End-plug/tube axis coaxiality•Wire tension

SITE WAS CERTIFIED ON MAY 1999

End-plug assembly procedureVisual inspectionMeasure end-plug diameter Clean all components in ultrasonic bath with 100% ethyl alcohol.Insert twister / stopperInsert springInsert/crimp copper pinInsert O-ring

Daily operational tasksCheck of air-condition system Verification of 200 and 8 Atm pressures ActionsCalibration of mechanical tension meterCalibration of Tube Length fixing systemCalibration of Tube length measurement system Packing / Unpacking Tubes Check of alignment

Wiring procedure Place tube to first position / scan bar code Thread wire in tube Insert wire through the endplugsCrimp wire on the left hand side Move to second position / respect clockingPass wire through right hand side tube crimperFix length (choosing gaps) with movable LHS crimper Secure and Crimp tube Perform pretension / tension Crimp wire on the right hand side Tube is ready

QA/QC procedureFinished tube Length measurementCoaxiality measurementWire tension measurementDark Current measurement

Tube verification Measure wall thicknessVisual inspectionClean if needed

Wire verification Visual inspectionThrow part if needed

SINCE THEN

Several Improvements with the aim •Minimize failures (rejected tubes)•Increase Production Rate•Reach Production Stability•Decrease Maintenance Operations

Wiring table reinforcement / expansion freedom

End-Plug Preparation go/no-go gauge / copper pin crimper

Wiring Tooling Wire crimpers + base / tube clamps / pressure valves

Automatization See E. Stefanides presentation

QA/QC Tooling Tube length meas./ coaxiality meas. / tension meas.

Operational Details

Upper: View of the wiring table during Module 0 production.Lower: View of the wiring table after the reinforcement upgrade.

Go/no-go gauge

Tooling for copper pin crimping on the brass sleeve.

The wire crimper holder

The micrometric adjustable mount of the tube clamp

Novel wire tensionmeter in use

low-cost compact reliable

Finished Tube Length

Wire Tension

Some Results

Tube Assembly as a function of time

As a summary …

Minimize failures

Dramatic decrease of accidental incidents

Decrease of failures due to tolerances

Increase Production Rate

5 min /tube + 2 min end-plugs

Reach Production Stability

Average of ~45 tubes /day

5800 MDTs assembled so far !!!

Decrease Maintenance Operations

Finance providing Our commitments will be fulfilled

M D T P ro d u ction - S ta tu s 28 F eb .01

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Glued Chambers

Chambers with Services

Plan Glued Chambers