New injectors: the Linac4 project and the new H− source

Linac4 is a new 160 MeV linear accelerator designed to improve by a factor of 2 the beam brightness out of the LHC injection chain for the needs of the LHC luminosity upgrade. The project started in 2008 and beam commissioning takes place in 2014–2015. The new linac accelerates H− ions that are then stripped at injection into the PS Booster; production of the H− beam takes place in a state-of-the-art ion source of the RF-driven caesiated surface type. Acceleration is provided by four different accelerating sections matched to the increasing beam velocity, including two of novel designs, and focusing is provided by a combination of permanent-magnet and electromagnetic quadrupoles.