Author: Bravin, E.
Paper Title Page
MOPF07 Turn by Turn Profile Monitors for the CERN SPS and LHC 216
  • S. Burger, A. Boccardi, E. Bravin, A. Goldblatt, A. Ravni, F. Roncarolo, R.S. Sautier
    CERN, Geneva, Switzerland
  In order to preserve the transverse beam emittance along the acceleration chain it is important that the optics of the transfer lines is perfectly matched to the optics of the rings. Special monitors capable of measuring the beam profiles with a turn by turn resolution are very helpful in this respect. A new type of matching monitor has been developed at CERN for the SPS and LHC machines. This monitor relies on imaging OTR light by mean of a fast line scan CMOS and an asymmetric optical system based on cylindrical lenses. This contribution describes the design of this monitor, presents the results obtained during the 2012-13 run and outlines the plans for further improving the design.  
MOPF08 Design and Performance of the Upgraded LHC Synchrotron Light Monitor 220
  • A. Goldblatt, E. Bravin, F. Roncarolo, G. Trad
    CERN, Geneva, Switzerland
  The LHC is equipped with two synchrotron radiation systems, one per beam, used to measure the transverse bunch distributions. The light emitted by a superconducting undulator and/or by a dipole magnet (depending on beam energy) is intercepted by an extraction mirror in vacuum and sent through a viewport to the imaging Beam Synchrotron Radiation Telescope (BSRT). The first version of the telescope, used from 2009 to mid 2012, was based on spherical focusing mirrors in order to minimize chromatic aberrations. However, this required a very complicated delay line in order to switch the focus between the two different light sources as a function of beam energy. A new system based on optical lenses was designed and installed in mid 2012 in order to simplify the optical line and thus reduce misalignment and focusing errors. The first results with LHC beam using this new system showed a significant reduction in the correction factor required to match the emittance as measured by wire scanners. This contribution discusses the performance of the new optical system, presenting the LHC results and comparing simulations with measurement performed in the laboratory using a BSRT replica.  
TUCL1 Overview of Imaging Sensors and Systems Used in Beam Instrumentation 331
  • E. Bravin
    CERN, Geneva, Switzerland
  The presentation will give an overview of applicable image sensors and sensor systems for an application in the beam instrumentation. The overview will cover fast imaging cameras as well as sensors and cameras to be used in radiation fields. The critical parameters will be discussed and measurements presented if available. Frame grabbers and digital cameras will also be included in the presentation.  
slides icon Slides TUCL1 [8.924 MB]  
TUPF02 Secondary Emission Monitor for keV Ion and Antiproton Beams 495
  • A.G. Sosa, E. Bravin, A. Jeff
    CERN, Geneva, Switzerland
  • J. Harasimowicz, A. Jeff, A.G. Sosa, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • J. Harasimowicz, A. Jeff, A.G. Sosa, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  Funding: Work supported by the EU within the DITANET and CATHI projects under contracts 215080 and 264330, HGF and GSI under contract VH-NG-328 and STFC under the Cockcroft Institute core grant ST/G008248/1.
Beam profile monitoring of low intensity keV ion and antiproton beams remains a challenging task. A Secondary electron Emission Monitor (SEM) has been designed to measure profiles of beams with intensities below 107 and energies as low as 20 keV. The monitor is based on a two stage microchannel plate (MCP) and a phosphor screen facing a CCD camera. Its modular design allows two different operational setups. In this contribution we present the design of a prototype and discuss results from measurements with protons at INFN-LNF and antiprotons at the AEgIS experiment at CERN*. This is then used for a characterization of the monitor with regard to its possible future use at different facilities.
* Measurements at the AD carried out with the AEgIS collaboration.
poster icon Poster TUPF02 [1.934 MB]  
WEAL3 Diffraction Radiation Test at CesrTA for Non-Intercepting Micron-Scale Beam Size Measurement 619
  • L.M. Bobb, E. Bravin, T. Lefèvre, S. Mazzoni
    CERN, Geneva, Switzerland
  • T. Aumeyr, P. Karataev
    Royal Holloway, University of London, Surrey, United Kingdom
  • M.G. Billing, J.V. Conway
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • L.M. Bobb
    JAI, Egham, Surrey, United Kingdom
  Diffraction radiation (DR) is produced when a relativistic charged particle moves in the vicinity of a medium. The electric field of the charged particle polarizes the target atoms which then oscillate, emitting radiation with a very broad spectrum. The spatial-spectral properties of DR are sensitive to a range of electron beam parameters. Furthermore, the energy loss due to DR is so small that the electron beam parameters are unchanged. DR can therefore be used to develop non-invasive diagnostic tools. To achieve the micron-scale resolution required to measure the transverse (vertical) beam size using incoherent DR in CLIC, DR in UV and X-ray spectral-range must be investigated. Experimental validation of such a scheme is ongoing at CesrTA at Cornell University, USA. Here we report on the test using 0.5 mm and 1 mm target apertures on a 2.1 GeV electron beam and 400 nm wavelength.  
slides icon Slides WEAL3 [2.893 MB]  
WEPF09 Profile and Emittance Measurements at the CERN LINAC-4 3 MeV Test Stand 826
  • F. Zocca, E. Bravin, M. Duraffourg, G.J. Focker, D. Gerard, U. Raich, F. Roncarolo
    CERN, Geneva, Switzerland
  A new 160 MeV H Linac named Linac-4 will be built at CERN to replace the old 50 MeV proton Linac. The ion source, the 3 MeV RFQ and the medium energy transport (MEBT) hosting a chopper, have been commissioned in a dedicated test stand. Wire grids and wire scanners were used to measure the transverse beam profile and a slit/grid emittance meter was installed on a temporary test bench plugged at the RFQ and MEBT exit in different stages. The emittance meter slit was also used as a scanning scraper able to reconstruct the transverse profile by measuring the transmission with a downstream current transformer. On the same measurement bench, a spectrometer in conjunction with a wire grid allowed measuring the energy spread of the particles. This paper summarizes the measurement results that allowed characterizing the 3 MeV beam and discusses the present understanding of monitor performance.