Transverse Profile and Emittance Measurements With a Laser Stripping System During the CERN LINAC4 Commissioning at 3 and 12 MeV

The CERN LINAC4 beam commissioning at 3 MeV was completed in early 2014 and the one at 12 MeV is ongoing. A novel system for measuring the transverse beam profile and emittance, based on low power laser stripping and H0 detection using a diamond detector, was successfully tested at these two energies. The measurement results agree with the operational slit-grid method within a few percent in terms of both transverse profile and emittance. After describing the general system setup, this remarkable achievement is discussed in detail together with the present limitations, which will be addressed in order to design a laser based emittance monitor for the LINAC4 top energy of 160 MeV.