ABSTRACT
This chapter looks at several ways of applying electric fields to charged particles to provide efficient and stable acceleration. It examines electrostatic accelerators and their limitations, before moving on to radio-frequency (RF) accelerators. DC power converters operating up to 600 kV are available at GW of power in the electricity industry and have undergone significant development for high-voltage DC transmission. Disk-loaded cavities have issues with multipactor at high gradient with electrons performing cyclotron orbits every half RF period in the magnetic field at the equator. In order to have an efficient accelerator we want the electromagnetic fields transported to the accelerating structure to remain in the accelerating structure, only decaying due to ohmic losses in the walls. Each cavity has a different phase of the RF field and the structure will behave like a transmission line with a phase and group velocity which can be altered by changing the coupling of the RF power through the holes in the disk.
