摘要
在2维小信号模型的基础上,分析了均匀和周期永久聚焦磁场对抑制返波自激振荡的影响。研究结果表明:改变聚焦磁场的幅值或周期来增加起振长度是可能的,而且不会改变基波的互作用条件。与此同时,对起振长度、初始非同步速度参量随皮尔斯增益参量、空间电荷参量、损耗参量等的变化,以及在超宽带行波管中当存在两个或多个角向非对称空间谐波时,起振长度、初始非同步速度参量随周期永久聚焦磁场的变化进行了研究。优化设计聚焦磁场、电子注和螺旋线慢波系统的参量可以对螺旋线行波管的稳定性分析提供必要的依据。
The influence of uniform magnetic field or PPM (periodic permanent magnetic) field on suppressing BWO (back-wave oscillation) is analyzed on the basis of the 2-D small signal model. It shows that it is possible to increase the start oscillation length by tailoring magnetic field's amplitude and its period without changing the synchronous condition of the fundamental wave; in the meantime, when there are two or more azimuthally asymmetric space harmonics in the high power broad-band helix TWT (traveling wave tube), the influences of the Pierce's gain parameter, space charge parameter, and loss parameter on the start oscillation length and real starting asynchronous velocity parameter are also analyzed. Thus the optimum values of the focusing magnetic field, electron beam and helical slow wave system can be obtained. The theory presented here can provide a strong basis for design of the helix TWT.
出处
《强激光与粒子束》
EI
CAS
CSCD
北大核心
2004年第7期918-922,共5页
High Power Laser and Particle Beams
基金
国家自然科学基金资助课题(10276011)
霍英东青年基金资助课题(81007)
关键词
螺旋线行波管
返波自激振荡
起振长度
聚焦磁场
Computer simulation
Differential equations
Magnetic fields
Magnetic flux
Microwave oscillators
Runge Kutta methods