Development and testing of 37.8 MHz, 3.0 kW RF amplifier system for Radioactive Ion Beam facility at VECC Kolkata

This paper reports the design, development and testing of a 3.0 kW, 37.8 MHz radio frequency (RF) amplifier system that has been built by combining four solid-state amplifier modules of 1.0 kW each. The design philosophy and test results of individual components such as driver amplifier, final amplifier modules, power divider/combiner, dual directional coupler (DDC) with system control and interlocks are discussed in detail. Compact 4-way Wilkinson power divider and combiner have been implemented using combination of 50 omega coaxial cables at this lower frequency of 37.8 MHz. It provides better isolation between the ports and also have high power handling capability. The amplifier has been tested with existing 37.8 MHz quarter-wave resonator type re buncher in the Radioactive Ion Beam (RIB) facility. The performance test results of developed RF system with Re buncher cavity have been presented in this report.