真空电子学太赫兹源的三维粒子模拟建模

Modeling of THz Vacuum Electronic Devices in 3D PIC Codes

太赫兹源是太赫兹技术发展应用的关键瓶颈之一,在太赫兹频段的低频一侧,真空电子学太赫兹源具有优势。对真空电子学太赫兹源的粒子模拟是设计和研制这类器件的重要手段,因此,关注粒子模拟的有效性,研究器件三维粒子模拟建模过程中的问题十分必要。本文以两种典型的太赫兹契伦科夫器件--太赫兹返波管和太赫兹行波管为例,讨论了器件粒子模拟模型中网格尺寸和宏粒子权重这两个关键参数对模拟结果的影响,进而给出了两个参数的合理选取方法,以供研究者们在对器件进行三维粒子模拟建模时参考。

THz vacuum electronic devices(VEDs)take advantages in the frequency range of 0.3~1 THz and have great potential in THz technologies and applications.PIC simulation has been essential in the design of THz VEDs.However,inappropriate setting of gird size and acro-particle weight in simulation can result in invalidity.Such invalidity has been observed in the simulation of a THz BWO and a THz TWT.The effects of the invalidity were analyzed and a reasonable modeling method for proper parameter setting was introduced.