Last week saw the start of the repositioning of the barrels that will eventually allow for the installation of the ECAL Preshower. This operation can only take place with all barrels in the closed position against the YB0 and both EndCaps in full open position. The first barrel to be closed is the YB+1. Last Tuesday, it was moved towards YB0 as to occupy the postion of the YB+2 when in the closed position. The decision to get into that configuration was driven by the needs from several subsystems:
HCAL: Exchange HO+ HPDs on the non-Interaction Point (non-IP) side of YB+1 Drift Tubes: Work on minicrates on the non-IP side of YB+1 ECAL: Recommissioning of EB supermodules (need to access the IP side of YB+1) Tracker: Work on +Z PP1 patch panels (need to access the inside of the vacuum tank)
Work on minicrates on the non-IP side of YB+1
It was also the opportunity to start the installation of temperature sensors on various places on the yoke including on the IP side of YB+1 & YB+2.
Exchange HO+ HPDs on the non-IP side of YB+1
One great success recorded last week was the completion of the ECAL +Z Super Modules recommissioning. This shows for the future that removing ECAL services to access DT chambers on YB0 is a well understood and well controlled process.
The plan is lock YB+1 by the middle of this week and to leave it in this configuration until next shutdown. This implies that all checks to be done in the YB0-YB+1 gap have to be final.
Meanwhile on the -Z end, repairs of the CSC chambers proceeded. The reinstallation of DT and ECAL LV cables on YB0 was well advanced allowing the recommissioning of the EB- Super Modules to start this week.
With just one month to go before the kick off of the Preshower installation, the Point 5 crew is recording very good progress on the many activities taking place at CMS.
CERN
