Author: Priebe, A.
Paper Title Page
WEPME044 Generation of Controlled Losses in Milisecond Timescale with Transverse Damper in LHC 3025
  • M. Sapinski, T. Baer, V. Chetvertkova, B. Dehning, W. Höfle, A. Priebe, R. Schmidt, D. Valuch
    CERN, Geneva, Switzerland
  A controlled way of generating of beam losses is required in order to investigate the quench limits of the superconducting magnets in the LHC. This is especially difficult to achieve for losses with millisecond duration. A series of experiments using the transverse damper system has proven that such a fast loss can be obtained even in the case of rigid 4 TeV beams. This paper describes the optimisation of beam parameters and transverse damper waveform required to mimic fast loss scenarios and reports on extensive tracking simulations undertaken to fully understand the time and spatial structure of these losses. The application of this method to the final quench tests is also presented.  
THPEA045 Beam Induced Quenches of LHC Magnets 3243
  • M. Sapinski, T. Baer, M. Bednarek, G. Bellodi, C. Bracco, R. Bruce, B. Dehning, W. Höfle, A. Lechner, E. Nebot Del Busto, A. Priebe, S. Redaelli, B. Salvachua, R. Schmidt, D. Valuch, A.P. Verweij, J. Wenninger, D. Wollmann, M. Zerlauth
    CERN, Geneva, Switzerland
  In the years 2009-2013 LHC was operating with the beam energy of 3.5 and 4 TeV instead of the nominal 7 TeV, with the corresponding currents in the superconducting magnets also half nominal. To date only a small number of beam-induced quenches have occurred, with most being due to specially designed quench tests. During normal collider operation with stored beam there has not been a single beam induced quench. This excellent result is mainly explained by the fact that the cleaning of the beam halo worked very well and, in case of beam losses, the beam was dumped before any significant energy was deposited in the magnets. However, conditions are expected to become much tougher after the long LHC shutdown, when the magnets will be working at near nominal currents in the presence of high energy and intensity beams. This paper summarizes the experience to date with beam-induced quenches. It describes the techniques used to generate controlled quench conditions which were used to study the limitations. Results are discussed along with their implication for LHC operation after the first Long Shutdown.