• E. Gschwendtner, A. Apyan, K. Elsener, A. Sailer, J.A. Uythoven
  CERN, Geneva
• R. Appleby, M.D. Salt
  UMAN, Manchester
• A. Ferrari, V.G. Ziemann
  Uppsala University, Uppsala

The 1.5TeV CLIC beams, with a total power of 14MW per beam, are disrupted at the interaction point due to the very strong beam-beam effect. As a result, some 3.5MW reach the main dump in form of beamstrahlung photons. About 0.5MW of e⁺e^- pairs with a very broad energy spectrum need to be disposed along the post-collision line. The conceptual design of this beam line will be presented. Emphasis will be on the optimization studies of the CLIC post-collision line design with respect to the energy deposition in windows, dumps and scrapers, on the design of the luminosity monitoring for a fast feedback to the beam steering and on the background conditions for the luminosity monitoring equipment.

• E. Gschwendtner, K. Elsener
  CERN, Geneva
• R. Appleby, M.D. Salt
  UMAN, Manchester
• A. Apyan
  Fermilab, Batavia
• A. Ferrari
  Uppsala University, Uppsala

The 1.5TeV CLIC beams, with a total power of 14MW per beam, are disrupted at the interaction point due to the very strong beam- beam effect. The resulting spent beam products are transported to suitable dumps by the post-IP beam line, which generates beam losses and causes the production of secondary cascades towards the interaction region. In this paper the electromagnetic background at the IP are presented, which were calculated using biased Monte Carlo techniques. Also, a first estimate is made of neutron back-shine from the main beam dump.

• 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.