High peak power test of S-band waveguide switches

The injector and source of particles for the Advanced Photon Source (APS) is a 2856-MHz S-band electron-positron linear accelerator (linac) which produces electrons with energies up to 650 MeV or positrons with energies up to 450 MeV. To improve the linac RF system availability, an additional modulator-klystron subsystem is being constructed to provide a switchable hot spare unit for each of the five existing S-band transmitters. The switching of the transmitters will require the use of SF6-pressurized waveguide switches at a peak operating power of 35 MW. A test stand was set up at the Stanford Linear Accelerator Center (SLAC) Klystron-Microwave laboratory to conduct tests characterizing the power handling capability of these waveguide switches. Test results are presented.