For nonlinear nonstationary theory of two-stream traveling-wave tube amplifier and two-stream amplifier: General equations and some results of calculation

In the work shows a way of developing the theory of nonlinear non-stationary two-beam traveling wave tube with a codirected beams, based on the nonlinear theory of traveling wave tube with a single electron beam.
The need to build a double-beam traveling wave tube theory arose from the study of twostream amplifier. It consists of an input device, an output device and the drift space, where two electron beams interact. In the input device there is a stream of modulation, which interact with each other in the drift space due to the phenomenon of two-stream instability. As input and output device of two-stream amplifier can be used spiral segments, so the input and output devices will be short section of double-stream traveling wave tube. Two-stream amplifier, due to lack of slow-wave system is a promising tool for advancement in terahertz region.
The purpose of this work is to construct a theory of nonlinear nonstationary two-beam traveling wave tube with codirected beams. Currently, there are a lot of works about twostream instability, much less work about a specific two-beam devices, none of them considers the time-dependent model.
The resulting system was solved numerically by the method of particles in cells. A comparison of the test results of the theory with nonlinear equations of two-stream amplifier that showed the correctness of derived equations. The comparison operation TWT and two-stream amplifier in the non-stationary area of operating conditions and in the interference area. The comparison of two-stream amplifier in which the inlet and outlet sections of the device modeled TWT, with dual beam traveling wave tube of the same length.