Study On Smith-Purcell Effect Free-electron Laser

Smith-Purcell effect free-electron laser (S-P FEL) is an important branch of free-electrons lasers. In the paper we analyze comprehensively this system based on the linear theory of S-P FEL. First we discuss the diffraction theory of the quasi-optical oscillator and induce the self-consistent integration equation and solution of the field distribution. And we develop numerical simulation program to simulate the distribution of the field. The linear theory of S-P FEL is researched in detail. Based on this theory we discuss the characters of Smith-Purcell Oscillator (SPO) and the Smith 桺urcell Amplifier (SPA) respectively . As a special example, we analyze Smith-Purcell FEL with variable grating period parameter in detail. Using the program we simulate the relations between the grating space frequency and the small sign gain, the efficiency, the start-oscillation current and the radiation power. A reference formula as how to choose the change rate of the grating parameter is also given. We can design satisfying Smith 桺urcell oscillator when the change rate is chosen properly. In the last section of the paper, based on the forerunner抯 achievements and my results , the calculation of characteristics and parameters of this sort of device has been formulated and discussed in detail. We try to construct the primary design principle and hope the work could help the successive research.