• S.S. Gilardoni, F. Arnold Malandain, E. Benedetto, T. Bohl, S. Cettour Cave, K. Cornelis, H. Damerau, F. Follin, T. Fowler, F. Franchi, P. Freyermuth, H. Genoud, R. Giachino, M. Giovannozzi, S. Hancock, Y. Le Borgne, D. Manglunki, G. Metral, L. Pereira, J.P. Ridewood, Y. Riva, M. Schokker, L. Sermeus, R.R. Steerenberg, B. Vandorpe, J. Wenninger
  CERN, Geneva

The Multi-Turn Extraction, a new type of extraction based on beam trapping inside stable islands in the horizontal phase space, has been commissioned during the 2008 run of the CERN Proton Synchrotron. Both single- and multi-bunch beams with a total intensity up to 1.4×10¹³ protons have been extracted with efficiencies up to 98%. Furthermore, injection tests in the CERN Super Proton Synchrotron were performed, with the beam then accelerated and extracted to produce neutrinos for the CERN Neutrino to Gran Sasso experiments. The results of the extensive measurement campaign are presented and discussed in details.

• A.C. Butterworth, M. E. Angoletta, L. Arnaudon, P. Baudrenghien, J. Bento, T. Bohl, O. Brunner, E. Ciapala, F. Dubouchet, G. Hagmann, W. Höfle, T.P.R. Linnecar, P. Maesen, J.C. Molendijk, E. Montesinos, J. Noirjean, A.V. Pashnin, V. Rossi, J. Sanchez-Quesada, M. Schokker, E.N. Shaposhnikova, D. Stellfeld, J. Tuckmantel, D. Valuch, U. Wehrle, F. Weierud
  CERN, Geneva
• R. Sorokoletov
  JINR, Dubna, Moscow Region

Hardware commissioning of the LHC RF system was successfully completed in time for first beams in LHC in September 2008. All cavities ware conditioned to nominal field, power systems tested and all Low level synchronization systems, cavity controllers and beam control electronics were tested and calibrated. Beam was successfully captured in ring 2, cavities phased, and a number of initial measurements made. These results are presented and tests and preparation for colliding beams in 2009 are outlined.

• E.N. Shaposhnikova, T. Bohl, T.P.R. Linnecar
  CERN, Geneva

Diagnostic techniques based on the Schottky spectrum of the peak detected signal have been used at CERN for a long time to study the behaviour of bunched beams. In this paper it is shown how the measured spectrum is related to the particle distribution in synchrotron frequency. The experimental set-up used and its limitations are also presented together with examples of beam measurements in the SPS and LHC.

• E.N. Shaposhnikova, T. Bohl, H. Damerau, K. Hanke, T.P.R. Linnecar, B. Mikulec, J. Tan, J. Tuckmantel
  CERN, Geneva

First reference measurements of the longitudinal impedance were made with beam in the SPS machine in 1999 to quantify the results of the impedance reduction programme, completed in 2001. The 2001 data showed that the low-frequency inductive impedance had been reduced by a factor 2.5 and that bunch lengthening due to the microwave instability was absent up to the ultimate LHC bunch intensity. Measurements of the quadrupole frequency shift with intensity in the following years suggest a significant increase in impedance (which nevertheless remains below the 1999 level) due to the installation of eight extraction kickers for beam transfer to the LHC. Microwave instability is still not observed up to the maximum bunch intensities available from injector. The experimental results are compared with expectations based on the known longitudinal impedance of the different machine elements in the SPS.