• D. Wollmann, O. Aberle, G. Arnau-Izquierdo, R.W. Assmann, J.-P. Bacher, V. Baglin, G. Bellodi, A. Bertarelli, A.P. Bouzoud, C. Bracco, R. Bruce, M. Brugger, S. Calatroni, F. Caspers, F. Cerutti, R. Chamizo, A. Cherif, E. Chiaveri, P. Chiggiato, A. Dallocchio, R. De Morais Amaral, B. Dehning, M. Donze, A. Ferrari, R. Folch, P. Francon, P. Gander, J.-M. Geisser, A. Grudiev, E.B. Holzer, D. Jacquet, J.B. Jeanneret, J.M. Jimenez, M. Jonker, J.M. Jowett, Y. Kadi, K. Kershaw, L. Lari, J. Lendaro, F. Loprete, R. Losito, M. Magistris, M. Malabaila, A. Marsili, A. Masi, S.J. Mathot, M. Mayer, C.C. Mitifiot, N. Mounet, E. Métral, A. Nordt, R. Perret, S. Perrollaz, C. Rathjen, S. Redaelli, G. Robert-Demolaize, S. Roesler, A. Rossi, B. Salvant, M. Santana-Leitner, I. Sexton, P. Sievers, T. Tardy, M.A. Timmins, E. Tsoulou, E. Veyrunes, H. Vincke, V. Vlachoudis, V. Vuillemin, Th. Weiler, F. Zimmermann
  CERN, Geneva
• I. Baishev, I.A. Kurochkin
  IHEP Protvino, Protvino, Moscow Region
• D. Kaltchev
  TRIUMF, Vancouver

The LHC has two dedicated cleaning insertions: IR3 for momentum cleaning and IR7 for betatron cleaning. The collimation system has been specified and built with tight mechanical tolerances (e.g. jaw flatness ~ 40 μm) and is designed to achieve a high accuracy and reproducibility of the jaw positions. The practically achievable cleaning efficiency of the present Phase-I system depends on the precision of the jaw centering around the beam, the accuracy of the gap size and the jaw parallelism against the beam. The reproducibility and stability of the system is important to avoid the frequent repetition of beam based alignment which is currently a lengthy procedure. Within this paper we describe the method used for the beam based alignment of the LHC collimation system, its achieved accuracy and stability and its performance at 450GeV.

Slides