• B. Dehning, D. Bocian, T.T. Boehlen, E. Effinger, J. Emery, F. Follin, V. Grishin, E.B. Holzer, H. Ikeda, S. Jackson, D.K. Kramer, G. Kruk, P. Le Roux, J. Mariethoz, M. Misiowiec, L. Ponce, C. Roderick, M. Sapinski, M. Stockner, C. Zamantzas
  CERN, Geneva
• A. Priebe
  Poznań University of Technology, Poznań

The LHC beam loss monitoring system (BLM) consists of about 4000 monitors observing losses at all quadrupole magnets and many other likely loss locations. At the first LHC operation in August and September 2008 all monitors were active and used to observe the losses during the initial beam steerings, at collimators, at the LHC dump and during aperture scans. The different loss patterns will be discussed and compared with the expectations originating from simulations. The observed signals of the BLM system will be analysed in terms of response time, sensitivity cross talk between channels and noise performance.