Development of 10 KW, 352 MHZ solid-state RF power amplifier for buncher cavity of proton accelerator

A 10 kW, 352 MHz solid-state RF power amplifier for a buncher cavity of Low Energy High Intensity Proton Liner accelerator (LEHIPA) has been developed. The power amplifier has been designed using two stage power combiners. Total sixteen power amplifiers of 850 W power output each, have been grouped into two groups with eight modules in each group. Each group of 8 modules have been combined using two 8-way power combiners. In second stage, a 2-way high power (>10 kW) combiner has been designed to combine output power of two groups. The total power gain of SSPA is 87 dB and total efficiency is 62.5% at 10 kW. The SSPA has been tested in both pulse and CW mode for buncher cavity requirement. The second and third harmonic levels are below 42 dBc and 59 dBc respectively. An interlock and protection system has been designed and integrated with the SSPA to monitor, display, and protect the modules against the failure of coolant or exceeding ratings or on reflected power condition. The paper presents the details of design and test results of the developed SSPA. (author)