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Bravin, E.

Paper Title Page
MOO1A02 High Resolution Transverse Profile Measurement 1
 
  • E. Bravin
    CERN, Geneva
  
  In many cases the performance of a particle accelerator is in large part defined by the transverse emittance of the beams. In most cases, like colliders and light sources (Synchrotrons or Free Electron Lasers), the quality of the final product, i.e. luminosity and brilliance, is directly linked to this parameter. For this reason many techniques and devices have been developed over the years for monitoring the transverse distribution of particles along accelerator chains or over machine cycles. Moreover modern designs of accelerators allow smaller size and/or higher current beams. New, more demanding, emittance measurement techniques have to be introduced and existing ones expanded. This presentation will review the different methods and the different instruments developed so far.  
TUPB28 A Large Scintillating Screen for the LHC Dump Line 132
 
  • T. Lefèvre, C. B. Bal, E. Bravin, S. Burger, B. Goddard, S. C. Hutchins, T. Renaglia
    CERN, Geneva
  
  7 TeV proton beam from the LHC is ejected through a long transfer line to a beam dump block. Approximately 100 m downstream of the ejection septa, a series of dilution kicker magnets provide a sweeping deflection spreading the extracted beam over a 40 cm diameter area on the face of the beam dump core. During normal operation, the quality of each dump event must be recorded and verified. The so called “Post-Mortem” data-set will include information from the beam dumping system as well as from the beam diagnostics along the extraction line. For this purpose, a profile monitor in front of the dump block is permanently available during machine operation. With more than 1014 protons stored in LHC, the thermal properties of the screen have to be considered as beam energy deposition becomes an issue. This paper presents the design of this device, which is original due to its very large size. We introduce the different technical considerations involved in the design of the system and present the complete layout of its installation with a special emphasis on the mechanical design, the screen assembly and the choice of the radiation-hard video camera used to capture the image.  
WEO1A03 Instrumentation for Longitudinal Beam Gymnastics in FEL's and in the CLIC test facility 3 215
 
  • T. Lefèvre, H.-H. Braun, E. Bravin, S. Burger, R. Corsini, S. Döbert, L. Søby, F. Tecker, P. Urschütz, C. P. Welsch
    CERN, Geneva
  • D. Alesini, C. Biscari, B. Buonomo, O. Coiro, A. Ghigo, F. Marcellini, B. Preger
    INFN/LNF, Frascati (Roma)
  • P. Craievich, M. Ferianis, M. Veronese
    ELETTRA, Basovizza, Trieste
  • A. E. Dabrowski, M. Velasco
    NU, Evanston
  • A. Ferrari
    UU/ISV, Uppsala
  
  Built at CERN by an international collaboration, the CLIC Test Facility 3 (CTF3) aims at demonstrating the feasibility of a high luminosity 3TeV e+-e- collider by the year 2010. One of the main issues to be demonstrated is the generation of a high average current (30A) high frequency (12GHz) bunched beam by means of RF manipulation. At the same time, Free Electron Lasers (FEL) are developed in several places all over the world with the aim of providing high brilliance photon sources. These machines all rely on the production of high peak current electron bunches. The required performances put high demands on the diagnostic equipment and innovative longitudinal monitors have been developed during the past years. This paper gives an overview of the longitudinal instrumentation developed at ELETTRA and CTF3, where a special effort was made in order to implement at the same time non-intercepting devices for online monitoring, and destructive diagnostics which have the advantage of providing more detailed information.  
WEPC14 Segmented Beam Dump for Time Resolved Spectrometry on a High Current Electron Beam 340
 
  • T. Lefèvre, H.-H. Braun, E. Bravin, C. Dutriat, C. P. Welsch
    CERN, Geneva
  
  In the CLIC Test Facility 3, the strong coupling between the beam and the accelerating cavities induces transient effects such that the head of the pulse is accelerated twice as much as the rest of the pulse. Three spectrometer lines are installed along the linac with the aim of measuring energy spread versus time with a 20ns resolution. The major difficulty is due to the high power carried by the beam which imposes extreme constraints of thermal and radiation resistances for the detector. This paper presents the design and the performances of a simple and easy-to-maintain device, called ‘segmented dump’. In this device, the particles are stopped inside metallic plates and the deposited charge is measured in the same way as in faraday cups. Simulations were carried out with the Monte Carlo code ‘FLUKA’ in order to evaluate the problems coming from the energy deposition and find ways to prevent or reduce them. The detector resolution has been optimized by choosing the adequate material and thickness for the plates. The overall layout of the monitor is described with a special emphasis on its mechanical assembly. Finally, limitations arising at high beam energies are discussed.