Design report of a 1 kW power amplifier for the PS RF 10 MHz system

The ability of the PS 10 MHz RF system to cope with high intensity beams mainly depends on the fast RF feedback loop that drastically reduces the cavity impedance seen by the beam. The present RF loop is built around a multi-stage, vacuum tube based amplifier that went through a long upgrade process to achieve an equivalent cavity impedance as seen by the beam of ∼400 Ω. The aim of further reducing the impedance below 400 Ω in view of the expected higher beam intensities, as well as the possibility of implementing a solid-state solution has triggered the present work. The following design shows that good performances can be achieved with RF MOSFETs, which can deal with high voltages and power and whose characteristics have been tested in a radioactive environment.