Gyrotron
Gyrotrons are high powered electron tubes which emit a millimeter wave beam by bunching electrons with cyclotron motion in a strong magnetic field. Typical output powers range from 10s of kilowatts to 1–2 megawatts. Output frequencies range from about 20 to 200 GHz. Gyrotrons can be designed for pulsed or continuous operation. Gyrotron manufacturers include CPI (USA), Gycom (Russia), Thales (EU), and Toshiba (Japan). A prevalent application of gyrotrons is as a source of plasma heating in nuclear fusion research experiments.