LHC Beam Loss Measurements and Quench Level Abort Threshold Accuracy

The LHC beam loss measurement system is designed to trigger the beam abort in case the magnet coil transition level from the superconducting to normal conducting sate is approached. The predicted heat deposition in the superconducting coils of the magnets has been determined by particle shower simulation codes, while for transient losses the enthalpy has been calculated. The results have been combined to determine the abort thresholds. Transient loss measurements of the energy depositions of lost protons with injected beams in the LHC are used to determine the accuracy of the beam abort threshold settings. The simulation predictions are reviewed and compared with the measurement results. The relative difference between measurements and simulation are between 30 to 50 %.