RF POWER GENERATION IN LINAC4

Linac4 is a lin­ear ac­cel­er­a­tor for neg­a­tive Hy­dro­gen ions (H-) which will re­place the old Linac2 as lin­ear in­jec­tor for the CERN ac­cel­er­a­tors. Its high­er en­er­gy of 160 MeV will give in­creased beam in­ten­si­ty in the down­stream ma­chines. Linac4 is about 100 m long, nor­mal-con­duct­ing, and will be housed in a tun­nel about 12 m below ground. The Linac4 tun­nel will be con­nect­ed to the ex­ist­ing chain of ac­cel­er­a­tors and can be ex­tend­ed to the new in­jec­tion chain. The high RF power for the Linac4 ac­cel­er­at­ing struc­tures will be gen­er­at­ed by thir­teen 1.3 MW klystrons, pre­vi­ous­ly used for the CERN LEP ac­cel­er­a­tor, and six new 2.8 MW klystrons of all op­er­at­ing at a fre­quen­cy of 352.2 MHz. The in­te­gra­tion of the RF power sys­tem in the build­ing is pre­sent­ed. The tech­ni­cal spec­i­fi­ca­tions and the per­for­mance of the var­i­ous high-pow­er el­e­ments are dis­cussed, with em­pha­sis on the re­quired re­tun­ing of the LEP klystrons. The power dis­tri­bu­tion sys­tem in­clud­ing the power split­ting re­quire­ments are also de­scribed.