1. Status on closing operations End cap calorimeter side A Forthcoming operations ATLAS – April 17th, 2009 Prepared by Michel RAYMOND

2. M. Raymond ATLAS – April 17 th, 2009 2 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 6 th & 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 Survey of the position :0.5 day, 3 surveyors April 9th April 14th Position is 3 mm further than nominal in Z EBA movement(1.5 h, 2 persons) Survey of the position : 0.5 day, 3 surveyors April 15thRe-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 Survey of the position :0.5 day, 3 surveyors April 16th EIL4S11 replacement

3. M. Raymond ATLAS – April 17 th, 2009 3 End Cap calorimeter – side A Summary of operations 1.5 to 2 hours of cryogenics preparatory work is needed,  1 st 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. 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 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.

4. M. Raymond ATLAS – April 17 th, 2009 4 4 End Cap A positioning in Z IP HO-A side Z Tile EB-A Lar EC-A 3545.0 mm nominal 3545.8 mm measured 6725.0 mm (as built) 6725.3 mm (2008 measurement) 3249.0 mm nominal without shims 3250.6 mm measured Min = -2.5 Max =+3.0 3206 mm with shims 6528.6 mm measured Min = -3.3 Max =+1.8 Estimated gaps between Barrel tile fingers and Extended Barrel : Min = 2 mm Max =7 mm Average = 4.0 mm Accuracy is 1 mm at one sigma level 3545.1 mm (2008 measurement) 6725.8 mm measured 3250.2 mm(2008) 6528.2 mm (2008)

5. M. Raymond ATLAS – April 17 th, 2009 55 End Cap A positioning in X, Y USA (-X) US (+X) +0.1+0.4 Top View Lar EC-A axis Tile EB-A axis HO side +Y (-0.9) -Y Side View Lar EC-A axis Tile EB-A axis IP side Nominal beam line (+0.7) (+0.6) -2.2 Nominal beam line -0.2 +0.6 +0.8 +0.2 (-0.2) (-1.0) (-1.8) -0.7 (-0.6) (-0.4)

6. M. Raymond ATLAS – April 17 th, 2009 6 Forthcoming operations April 20th/21st SW-A movement April 23rd/24thECT-A movement Beam pipe fixation to JD and survey EIL4 positioning April 27 th Light truck removing April 29 th Compressed truck lowering May 4 th JFC1 installed May 12 th JFC2 installed Work on LUCID May 13 th 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 ? Detectors on side A planned to be closed by the end of next week