UPDATE ON ID INTEGRATION Alice TB, E.Rosso ALICE TECHNICAL BOARD CERN, Ettore Rosso / CERN 1. 3 rd Cone 2. V0_L and Si_3 support 3. TPC & ITS rails

UPDATE ON ID INTEGRATION Alice TB, E.Rosso 3 rd Cone (RB26)

UPDATE ON ID INTEGRATION Alice TB, E.Rosso 3 rd Cone Sharing of responsibility ALICE (NBI team) will take the responsibility of the mechanical design of the 3 rd Cone, which should be approved by the VP team. The VP team will take care of the construction drawings and the fabrication of all elements between the VP and the adjustable beam pipe support (including). ALICE will give formal approval to all the construction drawings provided by the VP team. ALICE will take care of the construction drawings and the fabrication of the 3 rd cone. The VP team will give formal approval to all the construction drawings provided by ALICE.

UPDATE ON ID INTEGRATION Alice TB, E.Rosso, G. Schneider 3 rd Cone

UPDATE ON ID INTEGRATION Alice TB, E.Rosso, G. Schneider 3 rd Cone

UPDATE ON ID INTEGRATION Alice TB, E.Rosso 3 rd Cone Mechanical accuracy As pointed out by the Technical Coordinator, during the last Comprehensive Review, one of the reviewers insisted on the need to understand the mechanical accuracy of this cone in positioning the Si detectors. The FMD team is studying the problem and, in the near future, will provide the information about the spatial accuracy needed to match the expected performances of the Si detectors.

UPDATE ON ID INTEGRATION Alice TB, E.Rosso V0_L and Si_3 support (RB24)

UPDATE ON ID INTEGRATION Alice TB, E.Rosso V0_L and Si_3 support Responsibilities IPNL is considering the possibility to provide the design of the V0_L and Si_3 support, to be made out of C-fibre composite material. The decision should be taken by July 2003.

UPDATE ON ID INTEGRATION Alice TB, E.Rosso, T. Meyer TPC & ITS rails TPC

UPDATE ON ID INTEGRATION Alice TB, E.Rosso, F. Tosello, L. Simonetti TPC & ITS rails ITS

UPDATE ON ID INTEGRATION Alice TB, E.Rosso TPC & ITS rails Present situation The TPC slides tightly along only one of its two rails (mounted inside the Space Frame). The second allows the movement without constraint. ITS and VP slide tightly along only one of their two rails each of which is supported in six points: on RB26 side they are fixed to the muon absorber, on the RB24 to the assembly infrastructure and in between they slide through four supports bolted to the TPC. The second allows the movement without constraint. When moving the TPC inside the space frame, in case of misalignment between the rail guiding the TPC and the rail guiding ITS and VP, a stress would be applied to the system. Due to the tolerances in fabrication and positioning and the gravitational deformations of the various elements of the system, the local misalignment between TPC and ITS rails can reach a few millimeters in x and y.

UPDATE ON ID INTEGRATION Alice TB, E.Rosso TPC & ITS rails Conclusion In the present design, the TPC ITS system is statically over constraint; this would apply dangerous stress to detectors and vacuum pipe during the installation and make impossible to reinstall the ITS rails, once removed, in view of extracting detectors and/or vacuum pipe for maintenance.

UPDATE ON ID INTEGRATION Alice TB, E.Rosso TPC & ITS rails Actions foreseen In order to avoid constraint to the system in y due to the misalignment between the TPC and ITS rails during the TPC movement, L. Simonetti will study the possibility to leave a vertical play of ≥ 3 mm in the four supports of each of the ITS rails bolted to the TPC. In order to avoid constraint to the system in x due to the misalignment between the TPC and ITS rails during the TPC movement, D. Perini will study the possibility to reduce and/or compensate down to <±1 mm the cumulated fabrication and positioning error in x of the TPC rails mounted in the space frame.