Author: Verweij, A.P.
Paper Title Page
THPRB031 Operational Performance of the Machine Protection Systems of the Large Hadron Collider During Run 2 and Lessons Learnt for the LIU/HL-LHC Era 3875
 
  • M. Zerlauth, A. Antoine, W. Bartmann, C. Bracco, E. Carlier, Z. Charifoulline, R. Denz, B. Goddard, A. Lechner, N. Magnin, C. Martin, R. Mompo, S. Redaelli, I. Romera, B. Salvachua, R. Schmidt, J.A. Uythoven, A.P. Verweij, J. Wenninger, C. Wiesner, D. Wollmann, C. Zamantzas
    CERN, Geneva, Switzerland
  
  The Large Hadron Collider (LHC) has successfully completed its second operational run of four years length in December 2018. Operation will be stopped during two years for maintenance and upgrades. To allow for the successful completion of the diverse physics program at 6.5 TeV, the LHC has been routinely operating with stored beam energies close to 300 MJ per beam during high intensity proton runs as well as being frequently reconfigured to allow for special physic runs and important machine developments. No significant damage has incurred to the protected accelerator equipment throughout the run thanks to the excellent performance of the various machine protection systems, however a number of important observations and new failure scenarios have been identified, which were studied experimentally as well as through detailed simulations. In this contribution, we provide an overview of the performance of the machine protection systems throughout Run 2 as well as the important lessons learnt that will impact consolidation actions and the upgrade of the machine protection systems for the LIU/HL-LHC era.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB031  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPTS066 Beam Impact Experiment of 440GeV/p Protons on Superconducting Wires and Tapes in a Cryogenic Environment 4264
 
  • A. Will, A. Bernhard, A.-S. Müller
    KIT, Karlsruhe, Germany
  • Y. Bastian, B. Bordini, M. Favre, B. Lindstrom, M. Mentink, A. Monteuuis, A. Oslandsbotn, R. Schmidt, A.P. Siemko, K. Stachon, M.P. Vaananen, A.P. Verweij, A. Will, D. Wollmann
    CERN, Geneva, Switzerland
  • M. Bonura, C. Senatore
    UNIGE, Geneva, Switzerland
  • A. Usoskin
    BRUKER HTS GmbH, Alzenau, Germany
  
  The superconducting magnets used in high energy particle accelerators such as CERN’s LHC can be impacted by the circulating beam in case of specific failure cases. This leads to interaction of the beam particles with the magnet components, like the superconducting coils, directly or via secondary particle showers. The interaction leads to energy deposition in the timescale of microseconds and induces large thermal gradients within the superconductors in the order of 100 K/mm. To investigate the effect on the superconductors, an experiment at CERN’s HiRadMat facility was designed and executed, exposing short samples of Nb-Ti and Nb3Sn strands as well as YBCO tape in a cryogenic environment to microsecond 440 GeV/p proton beams. The irradiated samples were extracted and are being analyzed for their superconducting properties, such as the critical transport current. This paper describes the experimental setup as well as the first results of the visual inspection of the samples.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS066  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THPTS067 Characterisation of the Radiation Hardness of Cryogenic Bypass Diodes for the HL-LHC Inner Triplet Quadrupole Circuit 4268
 
  • D. Wollmann, C. Cangialosi, C. Cangialosi, F. Cerutti, G. D’Angelo, S. Danzeca, R. Denz, M. Favre, R. Garcia Alia, D. Hagedorn, A. Infantino, G. Kirby, L. Kistrup, T. Koettig, J. Lendaro, B. Lindstrom, A. Monteuuis, F. Rodriguez-Mateos, A.P. Siemko, K. Stachon, A. Tsinganis, M. Valette, A.P. Verweij, A. Will
    CERN, Geneva, Switzerland
  • A. Bernhard, A.-S. Müller
    KIT, Karlsruhe, Germany
  
  Funding: Work supported by the HL-LHC Project.
The powering layout of the new HL-LHC Nb3Sn triplet circuits is the use of cryogenic bypass diodes, where the diodes are located inside an extension to the magnet cryostat, operated in superfluid helium and exposed to radiation. Therefore, the radiation hardness of different type of bypass diodes has been tested at low temperatures in CERN’s CHARM irradiation facility during the operational year 2018. The forward characteristics, the turn on voltage and the reverse blocking voltage of each diode were measured weekly at 4.2 K and 77 K, respectively, as a function of the accumulated radiation dose. The diodes were submitted to a dose close to 12 kGy and a 1 MeV equivalent neutron fluence of 2.2x1014,n/cm2. After the end of the irradiation campaign the annealing behaviour of the diodes was tested by increasing the temperature slowly to 300 K. This paper describes the experimental setup, the measurement procedure and discusses the results of the measurements. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS067  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)