Design of a Triode Magnetron Injection Gun for a 1-MW 170-GHz Gyrotron

A triode magnetron injection gun (MIG) is designed for a 1-MW 170-GHz gyrotron, which will be used in an electron cyclotron resonance heating system for the International Thermonuclear Experimental Reactor. The initial design of MIG is performed by using the in-house code MIGSYN. For the electron-beam emission and propagation, the 2-D code EGUN is implemented. The transverse-to-axial velocity ratio α is 1.37, and the transverse velocity spread less than 4% is realized. The results are also validated against two other 2-D and 3-D codes, i.e., TRAK and CST-Particle Studio, respectively, which are in close agreement. From the fabrication and operation point of view, the parametric analysis and misalignment study of electron beam are also performed.