Author: Cheymol, B.
Paper Title Page
MOPME075 Laser Based Stripping System for Measurement of the Transverse Emittance of H Beams at the CERN LINAC4 652
  • T. Hofmann, E. Bravin, U. Raich, F. Roncarolo
    CERN, Geneva, Switzerland
  • B. Cheymol
    ESS, Lund, Sweden
  Funding: LA3NET is funded by the European Commission under Grant Agreement Number GA-ITN-2011-289191
The new LINAC4 at CERN will accelerate H particles to 160 MeV and allow high brightness proton beam transfers to the Proton Synchrotron Booster, via a charge-exchange injection scheme. This paper describes the conceptual design of a laser system proposed for transverse profile and emittance measurements based on photon detachment of electrons from the H ions. The binding energy of the outer electron is only 0.75 eV and can easily be stripped with a laser beam. Measuring the electron signal as function of the laser position allows the transverse beam profile to be reconstructed. A downstream dipole can also be used to separate the laser neutralized H0 atoms from the main H beam. By imaging these H0 atoms as a function of laser position the transverse emittance can be reconstructed in the same way as in traditional slit-and-grid systems. By properly dimensioning the laser power and spot size, this method results in negligible beam losses and is therefore non-destructive. In addition, the absence of material intercepting the H beam allows the measurement of a full power H beam. This paper will focus on the general design and integration of both the laser and H0 detector systems.