The potential for multipacting exists in waveguides, resonant cavities, and similar structures. It is primarily of interest in high-power devices, although it typically occurs in the relatively low-field regions of the device because multiple particles are only emitted as a result of low energy impacts. There are many applications in particle accelerators, where the design of beamline components such as RF modules and associated high-power feeds must include consideration of multipacting. Microwave feed systems often contain dielectric windows that are used to separate vacuum from normal pressure regions, and windows are susceptible to cracking/failure due to multipacting-induced heating. In superconducting structures, multipacting can cause localized heating that induces a quench, significantly impacting the performance of resonant cavities and related devices.