The effects of self-fields on the electron trajectory and gain in a two-stream electromagnetically pumped free-electron laser with axial guiding field

作     者：H.Mehdian S.Saviz 

作者机构：Department of Physics and Institute for Plasma ResearchTarbiat Moallem University Plasma Physics Research CenterScience and Research CampusIslamic Azad University 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2010年第19卷第1期

页      面：366-371页

核心收录：

学科分类：080901[工学-物理电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080401[工学-精密仪器及机械] 0804[工学-仪器科学与技术] 0803[工学-光学工程] 

主　　题：free electron laser two-stream 

摘      要：A theory of a two-stream flee-electron laser in a combined electromagnetic wiggler （EMW） is developed, in which we use an axial-guide magnetic field and take into account the effects of the self-fields. The electron trajectories and the small signal gain are derived. The stability of the trajectories, the characteristics of the linear-gain, and the normalised maximum gain are studied numerically. The results show that there are nine stable groups of orbits in the presence of self-fields instead of seven groups reported in the absence of the self-field. It is also shown that the normalised gains of four groups of the orbits are decreasing and those for the rest of them are increasing with growing J20. Furthermore, it is found that the two-stream laser with seff-field enhances the maximum gain in comparison with the single stream case.