University of Athens ATLAS BIS MDT assembly HEP 2001 Presented by Heraklion, 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 Physics CP violation

OUR AIM: Wire/ check all the Monitored Drift Tubes for the ATLAS BIS chambers 30,000 !! Tubes – 128 chambers With Construction specifications…: Wire position ± 25 μm Wire tension 350 ± 15 gr Gas leak rate < bar*l/s at 3 bar Leak at 3.4 kV (gain 1.6*10 5 ) < 2nA/m Finished tube length ± 0.25 mm …necessary to achieve the physics results

TO ACCOMPLISH AIM: Build a clean room 20±1 o C 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 procedure  Visual inspection  Measure end-plug diameter  Clean all components in ultrasonic bath with 100% ethyl alcohol.  Insert twister / stopper  Insert spring  Insert/crimp copper pin  Insert O-ring Daily operational tasks  Check of air-condition system  Verification of 200 and 8 Atm pressures Actions  Calibration of mechanical tension meter  Calibration of Tube Length fixing system  Calibration 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 endplugs  Crimp wire on the left hand side  Move to second position / respect clocking  Pass wire through right hand side tube crimper  Fix 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 procedure  Finished tube Length measurement  Coaxiality measurement  Wire tension measurement  Dark Current measurement Tube verification  Measure wall thickness  Visual inspection  Clean if needed Wire verification  Visual inspection  Throw 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