5 MW 805 MHz SNS RF System Experience

The RF system for the 805 MHz normal conducting linac of the Spallation Neutron Source (SNS) accelerator was designed, procured and tested at Los Alamos National Laboratory (LANL), and then installed and commissioned at Oak Ridge National Laboratory (ORNL). The RF power for the room temperature coupled cavity linac (CCL) of the SNS accelerator is generated by four, pulsed 5 MW peak-power klystrons operating with a pulse width of 1.25 ms and a 60 Hz repetition frequency. The RF power from each klystron is divided and delivered to the CCL through two separate RF windows. The 5 MW RF system advanced the state of the art for simultaneous peak and average power. This paper summarizes the problems encountered, lessons learned, and results of the high power testing at LANL of the 5 MW klystrons, 5 MW circulators, 5 MW loads, and 2.5 MW windows.