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Emery, J. E.

Paper Title Page
FRPMN071 The LHC Beam Loss Measurement System 4192
  • B. Dehning, E. Effinger, J. E. Emery, G. Ferioli, G. Guaglio, E. B. Holzer, D. K. Kramer, L. Ponce, V. Prieto, M. Stockner, C. Zamantzas
    CERN, Geneva
  One of the most important elements for the protection of CERN's Large Hadron Collider (LHC) is its beam loss monitoring system. It aims to prevent the super conducting magnets from quenching and to protect the machine components from damages, as a result of critical beam losses. This contribution reviews the design requirements: a high reliability to insure a safe protection and a high availability, a high dynamic range required by the beam dump trigger generation and beam tuning and finally a high radiation tolerance to be able to install the front-end electronics in the LHC tunnel. Examples of the reliability studies using the reliability ISOGRAPH fault tree software package are shown to explain the particular design. Measurement results from the LHC beam loss system installed at HERA (DESY) and at the SPS (CERN) are given to demonstrate its functionality. The detector design of the ionisation chambers and the secondary emission monitors are summarized and measurements with high and low intensity beams as well as with continuous and pulsed proton, muon and neutron beams are discussed.  
FRPMN072 LHC Beam Loss Detector Design: Simulations and Measurements 4198
  • B. Dehning, E. Effinger, J. E. Emery, G. Ferioli, E. B. Holzer, D. K. Kramer, L. Ponce, M. Stockner, C. Zamantzas
    CERN, Geneva
  The LHC beam loss monitoring system must prevent the super conducting magnets from quenching and protect the machine components from damage. 4000 gas filled ionization chambers are installed all around the LHC ring. They probe the far transverse tail of the hadronic shower induced by lost beam particles. Secondary emission chambers are placed in very high radiation areas for their lower sensitivity. This paper focuses on the signal response of the chambers to various particle types and energies and the simulated prediction of the hadronic shower tails. Detector responses were measured with continuous and bunched proton and mixed particle beams of 30 MeV to 450 GeV at PSI and CERN. Additional test measurements with 662 keV gammas and 174 MeV neutrons were performed on the ionization chamber. The measured signal speed, shape and absolute height are compared to GEANT4 and Garfield simulations. Aging data of SPS ionization chambers are shown. The far transverse tail of the hadronic shower induced by 40 GeV and 920 GeV protons impacting on the internal beam dump of HERA at DESY have been measured and compared to GEANT4 simulations.