Chapter 3: High-gradient RF structures and systems

Radio frequency (RF) systems are the workhorse of most particle accelerators and achieve high levels of performance and reliability. Despite five decades of improvement the community is still advancing RF performance with several novel developments. The next generation of particle accelerators will likely be still based on RF technology, but will require operational parameters in excess of state of the art, requiring an advanced R&D program. The R&D covers superconducting RF (SRF), normal conducting RF (NC RF) and ancillary systems such as RF sources, couplers, tuners and the systems that control them.