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ATLAS – April 17th, 2009. Status on closing operations. End cap calorimeter side A Forthcoming operations. Prepared by Michel RAYMOND. What is done on side A. Dismounting of access to SW-A : 0.5 day, 4 technicians. March 25th.
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ATLAS – April 17th, 2009 Status on closing operations End cap calorimeter side A Forthcoming operations Prepared by Michel RAYMOND
What is done on side A Dismounting of access to SW-A : 0.5 day, 4 technicians March 25th Dismounting of access to EBA : 1 day (0.5 day saved), 4 technicians April 6th Dismounting of round scaffolding : 1.5 day (2 days saved), 5 technicians April 6th & 7th The efficiency in scaffolding dismounting made possible the movement of the end cap calorimeter one day in advance Closing of End cap calorimeter : 0.5 day, ≈ 15 people April 9th Survey of the position : 0.5 day, 3 surveyors Position is 3 mm further than nominal in Z April 14th EBA movement (1.5 h, 2 persons) Survey of the position : 0.5 day, 3 surveyors EIL4S11 replacement April 15th Re-opening of EBA because of FEB problem at sector 9 : 0.5 d, ≈ 15 people Scaffolding installation (4 persons) Replacement of the board (2 persons) Closing of End cap calorimeter : 0.5 day, ≈ 15 people April 16th Survey of the position : 0.5 day, 3 surveyors
End Cap calorimeter – side A • Summary of operations • 1.5 to 2 hours of cryogenics preparatory work is needed, • 1st closing done in 3h15min (overall duration) • Correction of position : 1h35 min • Opening : 2h20min • 2nd closing : 4h10min (-30 min lunch pause) • It is important to take care of these durations regarding the radiation dose (individual and collective). A detailed follow up is done for each of these tasks. All the movements have been done without any trouble or difficulty : it is a good improvement compared to 2008 closing, when the flexible chain in sector 9 was damaged. Bcams are used in order to get a real time estimate of the position Comparison with survey results shows a magnitude of difference of -0.2/+1.1 mm depending on axis and measurements : for each coordinates the difference has a good repeatability that should make reliable the estimate of the position without waiting for the survey results 3
End Cap A positioning in Z 3206 mm with shims 6528.2 mm (2008) 6528.6 mm measured 3249.0 mm nominal without shims Min = -3.3 Max =+1.8 3250.6 mm measured 3250.2 mm(2008) Min = -2.5 Max =+3.0 Tile EB-A HO-A side IP Z 6725.0 mm (as built) 3545.0 mm nominal Lar EC-A 6725.8 mm measured 3545.8 mm measured 6725.3 mm (2008 measurement) 3545.1 mm (2008 measurement) Min = 2 mm Max =7 mm Average = 4.0 mm Estimated gaps between Barrel tile fingers and Extended Barrel : Accuracy is 1 mm at one sigma level 4
End Cap A positioning in X, Y +Y Side View +0.8 (+0.7) Lar EC-A axis +0.2 (+0.6) Nominal beam line -0.7 (-0.9) Tile EB-A axis -2.2 (-1.8) -Y IP side HO side US (+X) +0.6 (-0.2) Lar EC-A axis Tile EB-A axis +0.4 +0.1 (-0.4) (-0.6) Top View Nominal beam line -0.2 (-1.0) USA (-X) 5
Forthcoming operations April 20th/21st SW-A movement Beam pipe fixation to JD and survey EIL4 positioning Detectors on side A planned to be closed by the end of next week April 23rd/24th ECT-A movement April 27th Light truck removing April 29th Compressed truck lowering May 4th JFC1 installed Work on LUCID May 12th JFC2 installed May 13th Start of the optical fibers replacement on BW-A Option : in order to start the work on BW-A 1 week in advance, is it possible to have in parallel activities on BW and LUCID ?