Author: Bosco, A.
Paper Title Page
TUPF15 Overview of Laserwire Beam Profile and Emittance Measurements for High Power Proton Accelerators 531
 
  • S.M. Gibson, G.E. Boorman, A. Bosco
    Royal Holloway, University of London, Surrey, United Kingdom
  • G.E. Boorman, A. Bosco, S.M. Gibson
    JAI, Egham, Surrey, United Kingdom
  • C. Gabor
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • T. Hofmann
    CERN, Geneva, Switzerland
  • A.P. Letchford
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • J.K. Pozimski
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • J.K. Pozimski, P. Savage
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
 
  Laserwires were originally developed to measure micron-sized electron beams via Compton scattering, where traditional wire scanners are at the limit of their resolution. Laserwires have since been applied to larger beam-size, high power H ion beams, where the non-invasive method can probe beam densities that would damage traditional diagnostics. While photo-detachment of H ions is now routine to measure beam profiles, extending the technique to transverse and longitudinal emittance measurements is a key aim of the laserwire emittance scanner under construction at the Front End Test Stand (FETS) at the RAL. A pulsed, 30kHz, 8kW peak power laser is fibre-coupled to motorized collimating optics, which controls the position and thickness of the laserwire delivered to the H interaction chamber. The laserwire slices out a beamlet of neutralized particles, which propagate to a downstream scintillator and camera. The emittance is reconstructed from 2D images as the laserwire position is scanned. Results from the delivery optics, scintillator tests and particle tracking simulations of the full system are reviewed. Plans to deploy the FETS laser system at the Linac4 at CERN are outlined.  
poster icon Poster TUPF15 [9.196 MB]  
 
TUPF14 Description of Laser Transport and Delivery System for the FETS Laserwire Emittance Scanner 527
 
  • A. Bosco, G.E. Boorman, S. Emery, S.M. Gibson
    Royal Holloway, University of London, Surrey, United Kingdom
  • C. Gabor
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • T. Hofmann
    CERN, Geneva, Switzerland
  • A.P. Letchford
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • J.K. Pozimski, P. Savage
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
 
  A beam emittance monitor for H beams based on laser-induced ions neutralization is being developed at the Front End Test Stand (FETS) at the Rutherford Appleton Laboratory (RAL). The laser system that will be used for the photo-neutralization of the H beam is a fiber laser emitting 110 ns pulses at λ=1064nm, with a repetition rate of 30 kHz and peak power of 8 kW. The laser will be conveyed to the interaction area over a distance of 70 m via an optical fiber. An assembly of two remotely controlled motorized translation stages will enable the system to scan across the H beam along its vertical profile. A motorized beam expander will control the output size of the collimated laser beam in order to enable the system to operate with different spatial characteristics of the ions beam. In this paper we present a full account of the laser characteristics, the optical transport system and the final delivery assembly. All the relevant measurements such as power, spatial and temporal characteristics of the laser, fiber transport efficiency and final delivery laser beam parameters will be reported.  
poster icon Poster TUPF14 [4.081 MB]