• E.H.M. Wildner, F. Cerutti, A. Ferrari, A. Mereghetti, E. Todesco
  CERN, Geneva
• F. Broggi
  INFN/LASA, Segrate (MI)

Recent studies show that the energy deposition for the LHC phase one luminosity upgrade, aiming at a peak luminosity 2.5 10³⁴ cm^-2s^-1, can be handled by appropriate shielding. The phase II upgrade aims at a further increase of a factor 4, possibly using Nb3Sn quadrupoles. This paper describes how the main features of the triplet layout, such as quadrupole lengths, gaps between magnets, and aperture, affect the energy deposition in the insertion. We show the dependence of the triplet lay-out on the energy deposition patterns in the insertion magnets. An additional variable which is taken into account is the choice of conductor, i.e. solutions with Nb-Ti and Nb3Sn are compared. Nb3Sn technology gives possibilities for increasing the magnet apertures and space for new shielding solutions. Our studies give a first indication on the possibility of managing energy deposition for the phase II upgrade.

• L. Lari
  EPFL, Lausanne
• R.W. Assmann, M. Brugger, F. Cerutti, A. Ferrari, L. Lari, V. Vlachoudis
  CERN, Geneva
• Th. Weiler
  KIT, Karlsruhe

Due to the known limitations of Phase I LHC collimators in stable physics conditions, the LHC collimation system will be complemented by additional 30 Phase II collimators. The Phase II collimation system is designed to improve cleaning efficiency and to minimize the collimator-induced impedance with the main function of protecting the Super Conducting (SC) magnets from quenching due to beam particle losses. To fulfil these requirements, different possible innovative collimation designs were taken in consideration. Advanced jaw materials, including new composite materials (e.g. Cu–Diamond), jaw SiC insertions, coating foil, in-jaw instrumentation (e.g. BPM) and improved mechanical robustness of the jaw are the main features of these new promising Phase II collimator designs developed at CERN. The FLUKA Monte Carlo code is extensively used to evaluate the behavior of these collimators in the most radioactive areas of LHC, supporting the mechanical integration. These studies aim to identify the possible critical points along the IR7 line.

• F. Cerutti, F. Borgnolutti, A. Ferrari, A. Mereghetti, E.H.M. Wildner
  CERN, Geneva

While the Large Hadron Collider (LHC) at CERN is starting operation with beam, aiming to achieve nominal performance in the shortest term, the upgrade of the LHC interaction regions is actively pursued in order to enhance the physics reach of the machine. Its first phase, with the target of increasing the LHC luminosity to 2-3 10³⁴ cm^-2 s^-1, relies on the mature Nb-Ti superconducting magnet technology and is intended to maximize the use of the existing infrastructure. The impact of the increased power of the collision debris has been investigated through detailed energy deposition studies, considering the new aperture requirements for the low-beta quadrupoles and a number of other elements in the insertions. Effective solutions in terms of shielding options and design/layout optimization have been envisaged and the crucial factors have been pointed out.