Atlas status report

LHC Cooldown Status LHC is proceeding with the cooldown and the hardware commissioning L.Evans is asking the experiments to close the cavern by the 11 th of August

Today installation status Detector closed, mechanical installation ended with the positioning of the last shielding element on side A

Beam Pipe (including LUCID) Closed and on vacuum Bake out at 200C planned for the last week of July when Pixel cold again LUCID connected and being commissioned

Inner Detector All installed, but the TRT wheel C (2004 staging plan) TRT today is operational and in test mode SCT/PIXEL need to be cold again, before resuming full commissioning. This means that in the next few months they will be mostly in stand alone mode and will be always under the pressure to join the integrated ATLAS data taking setup

Solenoid Fully tested BT possible interference ruled out with a dedicated test Ready to go, we will not be allowed to have it on during beam tuning and first injections The mapping done last year has given us confidence that we will reach the necessary precision Recent Solenoid test with Barrel Toroid on

LAr Calorimeters Detector is closed. LAr fully installed, cryogenics working fine, damage on cryo line repaired, front end electronics and LV power refurbishing finished. HV problems are stable (hospital suppliers). A new problem came to the surface a few weeks ago. About half of the LV power suppliers of the end caps have a problem with the Barrel Toroid field. For some reason the dedicated B-shielding is not as effective as it was anticipated

Tile Calorimeter All installed, including MBAS scintillators All drawers have been refurbished, all LV powers repaired After closing a few drawers have experience failures and lost of communication, some of it was recovered : o 1 LVPS/HV side problem forces to operate with no HV control Need to correct for different gains offline. o One EB super drawer sends corrupted data always. The count of non usable for physics CELLS is 20 today: 14 in one EB SD and the rest 6 scattered randomly in the drawers There is for sure interest to open and get access during the shutdown to fix these problems

Muon spectrometer All muon chambers installed, a part the staged EE chambers All wheels in final position. The number of problematic channels is very small Still finishing up the connections in the barrel RPCs and the final alignment of a few EO chambers Most alignment rays are operational, showing excellent results

Muon spectrometer next RPCs still have to finish their commissioning before beam arrives Several gas inlets/outlets on the chambers have proven now to be fragile and a campaign of repairs will need to be planned for the next shutdown, which will imply some chambers movement and special access The readout fibers on the MDT big wheels need to be changed for radiation reasons. So the wheels need to be open and access. It is a major enterprise. We have now to plan a realistic scenario for the installation of the EE chambers during the next 2 shutdowns.

Toroids Repair on the He line of ECT-A done. Cooling process started. Still on track for testing the system starting in the last week of July The final balance of forces between end caps and barrel toroids still to be finalysed. In the worse case we might need access to the AFT brackets in July / August, by moving the big wheels back temporarily by few meters

Shieldings All shielding elements in place. We decided non to install the octagonal piece of the JF, to easy the opening during the next shutdown. This component will become important when we go over in luminosity Many and different radiation monitors have been deployed on the detector.

Infrastructure Ventilation: First indications show a temperature gradient of about 3C inside the detector with the maximum on top around 21C. This should be ok for the RPCs. The electrical network is now converging. A lot of debugging was necessary to be able to get the correct behavior in case of problems (see UPS). The gas system is converging, it is stable and performing in recycling mode (see RPC). The flammable gas system is the next in line for debugging. The various safety systems are converging.

What remains critical to be done before starting Bake out of all beam pipes at 200C to bring down pressure from mbar to mbar  need pixel cooling running stable Restart the Pixel/SCT commissioning with the detectors on Fix in sector 13 LAr LV power B-shielding. This probably means running at 15KA field …. Impact on mu-spectrometer trigger system to be understood Once the End-cap Toroid A is cool, test it and then start the overall magnets tests, including force balancing between barrel and end-caps Get TGCs to run stable with n-pentane Have the RPC connection work in the cavern finished Do an overall ventilation test which establishing the final pressure conditions everywere. Lower the temperature by 2-3C General clean up and UX15 in restricted access mode, LHC access system tests 11/15/2007M.Nessi 14

To be done before next shutdown Prepare an improved version of the round scaffolding to access calo region Do an full engineering study for a fast removal/substitution of the Be pipe in case of a major problem. Start preparing the tools Make a plan for consolidation/substitution of the present evaporative cooling proximity plant Prepare a plan for fixing all B-problems related to the LV Lar endcap power Make a plan for changing the MDT BW fibers. When? (barrel must be closed) Plan and preassemble for EE chambers insertion. When? Prepare a few new EIL4 TGC chambers to substitute the broken one 11/15/2007M.Nessi 15

During the next shutdown Open and test the new improved access/scaffolding system Before opening get all radiation protection procedures/tools operational Open calo to fix LV-Lar B-shielding, to fix tiles drawers, to check id-endplate leaks + ….. Open ID-shielding to eventually gain few cm in Z for the next closing (change shims on top fingers) Open MDT BW to change radiation resistant fibers ? Fix and substitute EIL4 TGC broken chambers Start installation of the EE chambers ? 11/15/2007M.Nessi 16