From Thomas.Hott@cern.ch Thu Dec 15 12:12:45 2005 Date: Tue, 13 Dec 2005 17:09:00 +0100 From: Thomas Hott To: Michel Lefebvre Cc: Martin Aleksa , Luis Hervas , Horst Oberlack , Thomas Hott Subject: Re: LAr End Cap C installation Dear Michel, thanks for the congratulations - to be honest, it wasn't trivial. 2 things turned out: i) It is absolutely necessary to remove the 4 pedestals and their warm cables, i.e. 2 on the left and 2 on the right, because they would block the access to the jacks and the support lenses where shims must to be inserted and bolts opened, resp. tightened. -> Please have a look to the attached photos - I made them to illustrate how difficult it is to access the necessary point even without pedestals and cables. On one photo you can see an allen key sticking in a bolt that is hidden behind a feedthrough. - I had to cut the key to be able to loosen the bolt at least the minimum bit that is required to insert the final support shims. ii) We can't reinstall the pedestals before the Tile Enxtend barrel is mechanically completed because we have to realign the LAR-EC then to the correct in height. This requires again access to the back jacks and support lenses. Unfortunately it can't be done now because we do not yet know where the Tile EB axis will be in height until the assembly is completed (don't forget, the aimed alignment precision is 1 mm and the Tile is still deforming until the last module is inserted representing eventually an ellipse rather than a circle). Cheers for the moment, Thomas >Dear Thomas, >Congratulations! >I hope you did not struggle too much with the space constraints near the >(removed) baseplanes. Following your experience with ECC, do you think it >is still required to disconnect the warm cables that >are on the two feedthroughs the furthest away from the place where you >need access? >Cheers >Michel -- Dr. Thomas Hott E-Mail: Thomas.Hott@cern.ch PH Department Mobile Phone: +41 76 487 49 26 CERN Office: Bdg 40-1D-01 CH-1211 Geneva 23 Phone: +41 22 767 12 32 Switzerland Fax: +41 22 767 83 50 [ Part 2.1, Application/APPLEFILE 74KB. ] [ Unable to print this part. ] [ Part 2.2, Application/OCTET-STREAM (Name: "P1010029.JPG") 615KB. ] [ Unable to print this part. ] [ Part 3.1, Application/APPLEFILE 74KB. ] [ Unable to print this part. ] [ Part 3.2, Application/OCTET-STREAM (Name: "P1010030.JPG") 605KB. ] [ Unable to print this part. ] [ Part 4.1, Application/APPLEFILE 74KB. ] [ Unable to print this part. ] [ Part 4.2, Application/OCTET-STREAM (Name: "P1010031.JPG") 601KB. ] [ Unable to print this part. ] [ Part 5.1, Application/APPLEFILE 74KB. ] [ Unable to print this part. ] [ Part 5.2, Application/OCTET-STREAM (Name: "P1010032.JPG") 584KB. ] [ Unable to print this part. ]