Consequences of RF Cavities

RF cavities are used to accelerate particles in particle accelerators. They work by storing energy in an oscillating electric field, which then accelerates the particles as they pass through the cavity. However, there are a number of consequences for RF cavities, including the emission of field electrons, the excitation of higher order modes, and the absorption of power from the beam.

Questions

• What are the consequences of field emission for RF cavities?
• What are higher order modes, and how do they affect RF cavities?
• How does the beam absorb power from RF cavities?

Answers

• Field emission is the emission of electrons from a conductor due to an intense electric field. This can be a problem for RF cavities, as it can lead to the formation of dark current, which can damage the cavity.
• Higher order modes (HOMs) are electromagnetic waves that can exist in RF cavities. HOMs can cause beam instabilities and can also lead to the absorption of power from the beam.
• The beam absorbs power from RF cavities through the interaction of the beam with the electric field in the cavity. This can lead to the heating of the cavity and can also reduce the efficiency of the cavity.