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Welsch, C.P.

Paper Title Page
MOPCH081 FLAIR: a Facility for Low-energy Antiproton and Ion Research 220
 
  • C.P. Welsch, C.P. Welsch
    CERN, Geneva
  • H. Danared
    MSL, Stockholm
 
  To exploit the unique possibilities that will become available at the Facility for Antiproton and Ion Research (FAIR), a collaboration of about 50 institutes from 15 countries was formed to efficiently enable an innovative research program towards low-energy antimatter-physics. In the Facility for Low-energy Antiproton and Ion Research (FLAIR) antiprotons and heavy ions are slowed down from 30 MeV to energies as low as 20 keV by a magnetic and an electrostatic storage ring. In this contribution, the facility and the research program covered are described with an emphasis on the accelerator chain and the expected particle numbers. An overview of the novel beam handling, cooling and imaging techniques as they will be required across the facility is given.  
MOPCH081 FLAIR: a Facility for Low-energy Antiproton and Ion Research 220
 
  • C.P. Welsch, C.P. Welsch
    CERN, Geneva
  • H. Danared
    MSL, Stockholm
 
  To exploit the unique possibilities that will become available at the Facility for Antiproton and Ion Research (FAIR), a collaboration of about 50 institutes from 15 countries was formed to efficiently enable an innovative research program towards low-energy antimatter-physics. In the Facility for Low-energy Antiproton and Ion Research (FLAIR) antiprotons and heavy ions are slowed down from 30 MeV to energies as low as 20 keV by a magnetic and an electrostatic storage ring. In this contribution, the facility and the research program covered are described with an emphasis on the accelerator chain and the expected particle numbers. An overview of the novel beam handling, cooling and imaging techniques as they will be required across the facility is given.  
TUPCH088 High Dynamic Range Beam Profile Measurements 1217
 
  • C.P. Welsch, E. Bravin, B. Burel, T. Lefevre
    CERN, Geneva
  • T. Chapman, M.J. Pilon
    Thermo, Liverpool, New York
 
  In future high intensity, high energy accelerators, beam loss has to be minimized to maximize performance and minimize activation of accelerator components. It is imperative to have a clear understanding of the mechanisms that can lead to halo formation and to have the possibility to test available theoretical models with an adequate experimental setup. Measurements based on optical transition radiation (OTR) provide an interesting opportunity for high resolution measurements of the transverse beam profile. In order to be applicable for measurements within the beam halo region, it is of utmost importance that a high dynamic range is covered by the image acquisition system. The existing camera system as it is installed in the CLIC Test Facility (CTF3) is compared to a step-by-step measurement with a photo multiplier tube (PMT) and measurements with a cooled charge injection device (CID) camera. The latter acquisition technique provides an innovative and highly flexible approach to high dynamic range measurements and is presented in some detail.  
TUPCH089 Investigations of OTR Screen Surfaces and Shapes 1220
 
  • C.P. Welsch, E. Bravin, T. Lefevre
    CERN, Geneva
 
  Optical transition radiation (OTR) has proven to be a flexible and effective tool for measuring a wide range of beam parameters, in particular the beam divergence and the transverse beam profile. It is today an established and widely used diagnostic method providing linear real-time measurements. Measurements in the CLIC Test Facility (CTF3) showed that the performance of the present profile monitors is limited by the optical acceptance of the imaging system. In this paper, two methods to improve the systems' performance are presented and results from measurements are shown. First, the influence of the surface quality of the OTR screen itself is addressed. Several possible screen materials have been tested to which different surface treatment techniques were applied. Results from the measured optical characteristics are given. Second, a parabolic-shaped screen support was investigated with the aim of providing an initial focusing of the emitted radiation and thus to reduce the problem of aperture limitation. Measured and calculated emission distributions are presented.  
TUPLS062 Cooling Rates at Ultra-low Energy Storage Rings 1633
 
  • C.P. Welsch, C.P. Welsch
    CERN, Geneva
  • A.V. Smirnov
    JINR, Dubna, Moscow Region
 
  Electrostatic low-energy storage rings have proven to be a highly flexible tool, able to cover experiments from a variety of different fields ranging from atomic, nuclear and molecular physics to biology and chemistry. Future machines will decisively rely on efficient electron cooling down to electron energies as low as some eV, posing new challenges to the cooler layout and operation. The BETACOOL code has already been successfully applied for the layout and optimization of a number of different electron coolers around the world. In this contribution, the results from calculations of the cooling rates at future low-energy machines equipped with an internal target like the Ultra-low energy Storage Ring (USR) at the Facility for Low-energy Antiproton and Ion Research (FLAIR) are presented.  
TUPLS062 Cooling Rates at Ultra-low Energy Storage Rings 1633
 
  • C.P. Welsch, C.P. Welsch
    CERN, Geneva
  • A.V. Smirnov
    JINR, Dubna, Moscow Region
 
  Electrostatic low-energy storage rings have proven to be a highly flexible tool, able to cover experiments from a variety of different fields ranging from atomic, nuclear and molecular physics to biology and chemistry. Future machines will decisively rely on efficient electron cooling down to electron energies as low as some eV, posing new challenges to the cooler layout and operation. The BETACOOL code has already been successfully applied for the layout and optimization of a number of different electron coolers around the world. In this contribution, the results from calculations of the cooling rates at future low-energy machines equipped with an internal target like the Ultra-low energy Storage Ring (USR) at the Facility for Low-energy Antiproton and Ion Research (FLAIR) are presented.  
TUPLS063 Layout of the USR at FLAIR 1636
 
  • C.P. Welsch, C.P. Welsch
    CERN, Geneva
  • M. Grieser, J. Ullrich, A. Wolf
    MPI-K, Heidelberg
 
  The Facility for Low-energy Antiproton and Ion Research (FLAIR) and a large part of the wide physics program decisively rely on new experimental techniques to cool and slow down antiprotons to 20 keV, namely on the development of an ultra-low energy electrostatic storage ring (USR). The whole research program connected with anti-matter/matter interactions is only feasible if such a machine will be realized For the USR to fulfil its key role in the FLAIR project, the development of novel and challenging methods and technologies is necessary: the combination of the electrostatic storage mode with a deceleration of the stored ions from 300 keV to 20 keV, electron cooling at all energies in both longitudinal and transverse phase-space, bunching of the stored beam to ultra-short pulses in the nanosecond regime and the development of an in-ring reaction microscope for antiproton-matter rearrangement experiments. In this contribution, the layout and the expected beam parameters of the USR are presented and its role within FLAIR described. The machine lattice and the cooler parameters are summarized.  
TUPLS063 Layout of the USR at FLAIR 1636
 
  • C.P. Welsch, C.P. Welsch
    CERN, Geneva
  • M. Grieser, J. Ullrich, A. Wolf
    MPI-K, Heidelberg
 
  The Facility for Low-energy Antiproton and Ion Research (FLAIR) and a large part of the wide physics program decisively rely on new experimental techniques to cool and slow down antiprotons to 20 keV, namely on the development of an ultra-low energy electrostatic storage ring (USR). The whole research program connected with anti-matter/matter interactions is only feasible if such a machine will be realized For the USR to fulfil its key role in the FLAIR project, the development of novel and challenging methods and technologies is necessary: the combination of the electrostatic storage mode with a deceleration of the stored ions from 300 keV to 20 keV, electron cooling at all energies in both longitudinal and transverse phase-space, bunching of the stored beam to ultra-short pulses in the nanosecond regime and the development of an in-ring reaction microscope for antiproton-matter rearrangement experiments. In this contribution, the layout and the expected beam parameters of the USR are presented and its role within FLAIR described. The machine lattice and the cooler parameters are summarized.  
MOPLS101 Beam Dynamics and First Operation of the Sub-harmonic Bunching System in the CTF3 Injector 795
 
  • P. Urschütz, H.-H. Braun, G. Carron, R. Corsini, S. Doebert, T. Lefevre, G. McMonagle, J. Mourier, J.P.H. Sladen, F. Tecker, L. Thorndahl, C.P. Welsch
    CERN, Geneva
 
  The CLIC Test Facility CTF3, built at CERN by an international collaboration, aims at demonstrating the feasibility of the CLIC scheme by 2010. The CTF3 drive beam generation scheme relies on the use of a fast phase switch of a sub-harmonic bunching system in order to phase-code the bunches. The amount of charge in unwanted satellite bunches is an important quantity, which must be minimized. Beam dynamics simulations have been used to study the problem, showing the limitation of the present CTF3 design and the gain of potential upgrades. In this paper the results are discussed and compared with beam measurements taken during the first operation of the system.  
TUPCH083 Time-resolved Spectrometry on the CLIC Test Facility 3 1205
 
  • T. Lefevre, C.B. Bal, H.-H. Braun, E. Bravin, S. Burger, R. Corsini, S. Doebert, C.D. Dutriat, F. Tecker, P. Urschütz, C.P. Welsch
    CERN, Geneva
 
  The high charge (>6microC) electron beam produced in the CLIC Test Facility 3 (CTF3) is accelerated in fully loaded cavities. To be able to measure the resulting strong transient effects, the time evolution of the beam energy and its energy spread must be measured with at least 50MHz bandwidth. Three spectrometer lines were installed all along the linac in order to control and tune the beam. The electrons are deflected by a dipole magnet onto an Optical Transition Radiation (OTR) screen, which is observed by a CCD camera. The measured beam size is then directly related to the energy spread. In order to provide time-resolved energy spectra, a fraction of the OTR photons is sent onto a multichannel photomultiplier. The overall set-up is described, special focus is given to the design of the OTR screen with its synchrotron radiation shielding. The performance of the time-resolved measurements are discussed in detail. Finally, the limitations of the system, mainly due to radiation problems, are discussed.