• C. Yin Vallgren, G. Arduini, J. Bauche, S. Calatroni, P. Chiggiato, K. Cornelis, P. Costa Pinto, E. Métral, G. Rumolo, E.N. Shaposhnikova, M. Taborelli, G. Vandoni
  CERN, Geneva

Amorphous carbon coatings with low secondary electron yield have been applied to the liners in the electron cloud monitors and to vacuum chambers of three dipole magnets in the SPS. The electron cloud is completely suppressed for LHC type beams in these monitors even after 3 months air venting and no performance deterioration is observed after more than one year of SPS operation. Upon variation of the magnetic field in the monitors the electron cloud current maintains its intensity down to weak fields of some 40 Gauss, where fast conditioning is observed. This is in agreement with dark traces observed on the RF shields between dipoles. The dynamic pressure rise has been used to monitor the behavior of the magnets. It is found to be about the same for coated and uncoated magnets, apart from a weak improvement in the carbon coated ones under conditions of intense electron cloud. Inspection of the coated magnet is foreseen in order to detect potential differences with respect to the coated monitors. Measurements of the stray fields outside the dipoles show that they are sufficiently strong to induce electron cloud in these regions.

• M. Giovannozzi, E. Benedetto, A. Blas, T. Bohl, S. Cettour Cave, K. Cornelis, D.G. Cotte, H. Damerau, M. Delrieux, J. Fleuret, F. Follin, T. Fowler, P. Freyermuth, H. Genoud, S.S. Gilardoni, S. Hancock, O. Hans, Y. Le Borgne, D. Manglunki, E. Matli, G. Metral, E. Métral, M. Newman, L. Pereira, F.C. Peters, Y. Riva, F. Roncarolo, L. Sermeus, R.R. Steerenberg, B. Vandorpe, J. Wenninger
  CERN, Geneva
• F. Franchi
  ESRF, Grenoble

Following the analysis of the results obtained during the first year of beam commissioning of the CERN multi-turn extraction, a number of changes have been introduced in the beam manipulations performed in the CERN Proton Synchrotron. This includes a different control of the linear chromaticity, the setting of the non-linear magnets used to split the beam, and the longitudinal structure in the PS. The results obtained during the 2009 run are presented and discussed in detail, including the beam performance in both the PS and the SPS, as well as the optics measurements in the transfer line between the two circular machines.

Slides

• E. Gschwendtner, K. Cornelis, I. Efthymiopoulos, A. Ferrari, A. Pardons, W. Treberspurg, H. Vincke, J. Wenninger
  CERN, Geneva
• D. Autiero
  IN2P3 IPNL, Villeurbanne
• A. Guglielmi
  INFN/LNL, Legnaro (PD)
• P.R. Sala
  Istituto Nazionale di Fisica Nucleare, Milano

The CNGS facility (CERN Neutrinos to Gran Sasso) aims at directly detecting muon to tau neutrino oscillations. An intense muon-neutrino beam (10¹⁷ muon neutrinos/day) is generated at CERN and directed over 732km towards the Gran Sasso National Laboratory, LNGS, in Italy, where two large and complex detectors, OPERA and ICARUS, are located. CNGS is the first long-baseline neutrino facility in which the measurement of the oscillation parameters is performed by observation of the tau-neutrino appearance. The facility is approved for a physics program of five years with a total of 22.5·10¹⁹ protons on target. Having resolved successfully some initial issues that occurred since its commissioning in 2006, the facility had its first complete year of physics in 2008. By the end of the 2009 physics run the facility will have delivered in total more than 5·10¹⁹ protons on target corresponding to ~2-3 tau neutrino events in the OPERA detector. The experiences gained in operating this 500 kW neutrino beam facility along with highlights of the beam performance in 2008 and 2009 are discussed.