Linear accelerator 4 (Linac 4) is designed to boost negative hydrogen ions to high energies. It is scheduled to become the source of proton beams for the Large Hadron Collider (LHC) after the long shutdown in 2019-2020.Linac 4 will accelerate ions to 160 MeV to prepare them to enter the Proton Synchrotron Booster, which is part of the LHC injection chain. Negative hydrogen ions are pulsed through the accelerator for 400 microseconds at a time.Linac 4 accelerates negative hydrogen ions, which eventually approach the speed of light.Ultra clean vacuum conditions are needed in order for the ions to travel freely . Agilent Ion Pumps have been selected as the main pumping for Linac 4 at CERN , as well as for most of the other particle accelerator at CERN and other laboratories all over the worldLinac 4 is 80 metres long and located 12 metres below ground. ,and it is an important milestone in the project to increase the luminosity of the LHC during the next decade.