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Koopman, J.

Paper Title Page
CT07 Excitation of Large Transverse Beam Oscillations without Emittance Blow-Up Using the "AC-Dipole" Principle 82
 
  • O. Berrig, W. Höfle, R. Jones, J. Koopman, J.-P. Koutchouk, F. Schmidt
    CERN, Geneva, Switzerland
 
  The so-called "AC-Dipole" principle allows the excitation of transverse oscillations to large (several σ) excursions without emittance blow-up. The idea was originally proposed and tested at BNL for resonance crossing with polarized beams, using an orbit corrector dipole with an excitation frequency close to the betatron tune, hence "AC-Dipole". This method of beam excitation has several potential applications in the LHC, such as phase advance and β-measurements, dynamic aperture studies and the investigation of resonance strengths. The technique was recently tested in the CERN-SPS using the transverse damper as an "AC-Dipole" providing the fixed frequency excitation. results from this experiment are presented, along with an explanation of the underlying principle.  
PM15 Sensitivity Studies with the SPS Rest Gas Profile Monitor 201
 
  • G. Ferioli, C. Fischer, J. Koopman, M. Sillanoli
    CERN, Geneva, Switzerland
 
  During the SPS run in the year 2000 further test measurements were performed with the rest gas monitor. First, profiles of single circulating proton bunches were measured and the bunch charge progressively reduced, in order to determine the smallest bunch intensity which can be scanned under the present operating conditions. The image detector in this case was a CMOS camera. Using a multi-anode strip photo-multiplier with fast read-out electronics, the possibility to record profiles on a single beam passage and on consecutive turns was also investigated. This paper presents the results of these tests and discusses the expected improvements for the operation in 2001. Moreover, the issue of micro channel plate ageing effects was tackled and a calibration system based on electron emission from a heating wire is proposed. The gained experience will be used for the specification of a new monitor with optimised design, to be operated both in the SPS and in the LHC.