RF Power Amplifier for the CERN SPS Operating as LEP Injector

To permit electron-positron acceleration in the SPS, a new 200 MHz RF system will be installed. The system consists of 32 single-cell, high Q accelerating cavities, providing a total peak accelerating voltage of 30 MV. Each cavity will be equipped with an RF power amplifier, capable of delivering 60 kW CW or 110 kW pulsed power (pulse length up to 1 second, duty cycle up to 20 %). The power amplifier will be mounted directly on top of the cavity. Since the space in the existing SPS tunnel is very limited, a compact amplifier is needed, requiring special RF circuitry design. Also the choice of material is restricted due to the presence of ionizing radiation in the tunnel. This paper describes the design of the amplifier and presents the test results, obtained on a prototype version.