ATLAS Upgrade SCT Inner Detector Barrel end region Layout, services, %Xo and space envelopes

1. ATLAS Upgrade SCT Inner Detector Barrel end region Layout, services, %Xo and space envelopes T.J.Fraser UCL, A.Nichols RAL The impact of services off the ends of the SCT is being studied as a continuous task from this early stage so that the design process of the inner detector layout does not overlook important considerations. To this end a Materials spreadsheet has been set up which relates directly to barrel end drawings. Components such as cooling pipes, connectors and manifolds, power bus tapes /cables and optical readout cables/fibres and interface PCBs can be entered onto the spreadsheet and added to the drawings. Both spreadsheet and drawings are updated in parallel as parameters such as lengths, diameters, numbers of units and materials etc change. Initially, all the elements entered are hypothetical but these will be more realistic as R&D in cooling, power and readout progresses. Some major concerns at present, which impact on the barrel end design are: no decision on which services on the cryostat will be reused and which removed. the huge number of module cooling pipes (in comparison with current SCT) the size and location of the readout interface boards. the SS and LS barrel concept (rather than equal length barrel staves)

2. Plots on current Materials Spreadsheet The Spreadsheet at present has cooling pipes and power tapes. Other items will be added as more information becomes available. Parameters such as mass, volume, %Xo, and total %Xo are calculated and some comparisons with the current SCT can be made. Variations on all components at the barrel end will be included in subsequent versions. The Spreadsheet is designed to work with the corresponding drawings (X-sections in Z and A0 R/PHI drawings) and will not be changed without the equivalent changes to the drawings which consist of X-sections in Z and a barrel end drawing In R/PHI.