• B. Cheymol, E. Bravin, C. Dutriat, A.E. Lokhovitskiy, U. Raich, F. Roncarolo, R. Scrivens, E. Zorin
  CERN, Geneva

LINAC4 is the first step in the upgrade of the injector chain for the LHC and will accelerate H^- ions to 160 MeV. The ion source has initially been installed in a laboratory setup where its commissioning started at the end of 2009. A slit-grid system is used to monitor the transverse emittance at the exit of the source. Measurement results have been compared to analytical and numerical predictions of the system performance, addressing the system resolution, accuracy and sensitivity. This information has been used to improve the design of a new slit-grid system required for commissioning the linac at higher energies.