CAS course on "RF for Accelerators", 18 June - 01 July 2023, Berlin Germany

In order to maximise the power delivered to the cavity we must minimise reflections. Reflections are minimised when the source and load impedances are equal, however this is difficult when the cavity impedance is orders of magnitude higher than the source. A power coupler acts like a transformer changing the cavity impedance “seen” by the source allowing matching. This lecture looks at what impedance matching means, how to match RF cavities, transient filling behaviour of cavities, power requirements for real cavities with beam, and matching travelling wave structures