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Agenda

Agenda. Movements during transport ReFiducialisation at CERN Alignement in the tunnel Conclusions. The fiducialisation is done at FNAL with the SSW CERN has received all files with the fiducialisation values

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Agenda

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  1. Agenda • Movements during transport • ReFiducialisation at CERN • Alignement in the tunnel • Conclusions

  2. The fiducialisation is done at FNAL with the SSW • CERN has received all files with the fiducialisation values • At CERN, only a verification was foreseen to check the position of the cold mass(blocks)/cryostat(fiducials) • It was done on 10 first magnets • No important vert. and trans. movements • Some important long. movements OVERVIEW Movement during transport

  3. Movement during transport

  4. OVERVIEW AT CERN between SMI2 and tunnel The HCLQXC_001-FL000006 in position Q3R8 • was measured in the tunnel and a movement of the CM/cryostat of 6mm in the long. direction was detected wrt the last measurement in SMI2 • It was put back to its nominal position just by pushing the CM against the cryostat. No mechanical modification was done • The question was araised by TS/SU : What will happen during a cool down if it moves so easily ? No answer Movement during transport

  5. Because of • deviations between FNAL and CERN measurements • Uncertainties due to the stability of the spiders • it was decided to remeasure/recalculate the fiducialisation of all the magnets using : • measurements inside the cold bore tubes to determine Y axis (CERN) • The roll angle for the xy plane (FNAL) • The long. origine (FNAL)with an accuracy of +- 5mm • And in some cases to make complementary • Magnetic measurements with AC mole (CERN) • Magnetic measurements with SSW (CERN) • Determination of a new set of parameters for all the magnets • This new geometry was used by MEB to approve them OVERVIEW Re-Fiducialisation at CERN

  6. During the fiducialisation operation, the position of the tubes at each extremity are measured and the position determined in the new co-ordinate system • The docs were put in MTF • if we were to apply the tolerances used for Arc dipoles/SSSs, there would have been a lot of NCs to open • But we were told not open them because • a new interface spec. was in preparation • The FNAL people were to realise the interconnection work themselves and supposed to cope with their NCs • Effectively, the new spec. LHC-LQX-ES-0012 was established and almost all the NC disappeared. The remaining ones were opened in MTF. Angles of flanges out of tolerance. OVERVIEW Re-Fiducialisation at CERN

  7. Longitudinal position OVERVIEW Cartography at CERN

  8. OVERVIEW Longitudinal problem : • The longitudinal errors of the CBT was solved by giving shifts • But in several cases , the physics people are not happy with the long.position chosen • The problem is more difficult to solve when the offset is NOT the same for CBT and cryostat : in this case we are not in the middle of the range for the jacks once the magnet is aligned Cartography at CERN

  9. OVERVIEW Modification of design of spiders : • It has to be check that there is no movement of the cold mass/cryostat • A new fiducialisation is no longer possible because the magnets are equipped with beam screens (and BPM fro Q2) • A check of the cold mass/cryostat could be done in situ but there are not enough references on the cold mass (only two blocks and in some cases 0). Temporary blocks must be installed and measured before and after the modification Re-Fiducialisation at CERN

  10. Specifications of the alignment are in LHC-G-ES-0016 • Inner triplet mean line wrt LHC (LSS) line : 0.3mm(rms) in X, 0.1mm(rms) in Z • One magnet wrt the inner triplet mean line in stability : several microns • Inner triplet mean line wrt inner triplet on the other side : • 0.2mm(rms) in X, 0.1mm(rms) in Z for IR2 and 8 • 0.1mm(rms) in X, 0.1mm(rms) in Z for IR1 and 5 Sequence of the operations : • The first alignment takes place while the magnets are NOT connected to their neighbours • Installation of the Survey monitoring equipment : HLS + WPS+ motors • Smoothing operation done when the magnets are connected and cold. Realignment could be done manually or automatically OVERVIEW Alignment in the tunnel

  11. Specifications for the motors : • The spec is LGC-GIJ-CI-0003 • There is no possibility to align in the long.(Y) direction. No constraints should be present in this direction. No test was done for this situation • Possibility to realign in the vertical (Z) and transversal direction(X) in a range of +- 2mm. The transverse force induced by slope, tilt and the interconnect should not exceed 1T • Therefore the new design of tie rods should NOT transfer the efforts into the jacks OVERVIEW Alignment in the tunnel

  12. No mvt of jack/floor Mvt of jack/cryostat => long. constraint in the jack Movement during vacuum pumping Alignment in the tunnel due to tie rod • This has to be avoided

  13. Check fiducialisation after modification • To take into consideration for design modification • The reinforcement of the tie rods should not rigidify the interconnect so that the transverse force exceeds 1T • The modification should not transfer the long. efforts into the jacks which are not designed for that purpose OVERVIEW Conclusions

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