Electron rf Oscillator Based on Self-Excitation of a Talbot-Type Supermode in an Oversized Cavity

Powerful terahertz masers are required for various important applications, such as heating and current drive in controlled nuclear fusion. Traditional relativistic electron masers are based on emission of a fixed transverse mode of the operating cavity; at terahertz frequencies, oversized cavities are obviously needed, and it is difficult to provide single-mode generation. This study proposes a fresh strategy for solving this problem, based on excitation of a supermode formed by a fixed set of partial transverse cavity modes. The approach is interesting as a means to realize high-power sources of coherent terahertz radiation.