RF phasing of the Duke linac

The injector of Duke storage ring is a 295 MeV S-band linear accelerator (linac) which consists of 3 klystrons and 11 accelerator sections. The phase adjustment between klystrons is achieved by means of 2 commercial coaxial phase shifters in the klystron drive line. The phase between accelerator sections is balanced on the low power level after the waveguide installation. A mechanical high power waveguide phase changer has been developed and installed for each accelerator section. During the high power operation, the waveguide phase can be changed remotely by driving gearmotor to deform the waveguide cross section. The test results and high power performance are reported.