Operating Parameters of High Power RF Systems in Particle Accelerators based on Equivalent Circuit Analysis.

This tutorial style publication covers elementary design and performance of high power RF systems in particle accelerators. It reviews the basics and presents an analysis of inductive and capacitively coupled systems leading to the commonly used simplified circuit equivalent model of power source, coupling, cavity and beam. The transformation of the various ’real’ circuit parameters such as current, voltage and impedance to the circuit equivalent is presented and frequency shifts due to coupling calculated. Power requirements as function of RF voltage and beam intensity are derived. The influence of parameters such as impedance, detuning, coupling and matching are described. The differences between superconducting and conventional room temperature cavitiy systems are highlighted. Some specific topics are discussed: stability with high beam loading, the operation of systems with multiple cavities sharing a common power source and for high power linacs power requirements in low and high beta sections.