• C. Bracco, R.W. Assmann, W. Bartmann, C. Boucly, R. Bruce, E. Carlier, B. Dehning, B. Goddard, E.B. Holzer, M. Meddahi, A. Nordt, S. Redaelli, A. Rossi, M. Sapinski, J.A. Uythoven, D. Wollmann
  CERN, Geneva

A single-sided mobile diluter (TCDQ) and a horizontal secondary collimator(TCSG) are installed in the extraction region of the LHC to protect the downstream elements from damage in case of asynchronous beam dump. These collimators have to be precisely setup to shield the arc aperture at 450 GeV, the triplet apertures and the tungsten tertiary collimators (TCT) at the low-beta collision points. During the LHC beam commissioning, several machine protection tests were carried out to validate collimator setup and hierarchy at different beam energies and intensities. The outcomes of these measurements are presented in this paper together with the results of particle tracking simulations for asynchronous beam dump. These studies allowed to quantify the leakage expected from dump protection collimators to the downstream elements, and to validate the system performance towards higher beam intensity.