Abstract:

An upgrade of the Advanced Photon Source 352MHz rf systems is underway that involves phasing out the existing APS klystron vacuum tube rf power amplifiers and replacing them with state-of-the-art solid state rf amplifier (SSA) technology. Laterally-diffused metal oxide semiconductor (LDMOS) transistors are used to produce approximately 1.25kW of cw rf power per device, followed by a series of rf power structures that combine the module outputs to achieve 160kW cw final output power per system.  This SSA upgrade eliminates the need for high voltage dc power, reduces noise on the rf power, provides built-in power redundancy, and improves system reliability.  The APS solid state rf system topology will be discussed, along with R&D efforts in solid state, implementation plans for the 160kW SSA systems, and a brief review of klystron performance and operating history at APS.