Gerasimov Michael, Dyunin Egor, Gerasimov Jacob, Ciplis Johnathan, Friedman Aharon
Department of Electrical and Electronic Engineering, Ariel University, Ariel 40700, Israel.
Sensors (Basel). 2021 Dec 29;22(1):240. doi: 10.3390/s22010240.
The construction of a transmission line (TL) for a wide tunable broad-spectrum THz radiation source is not a simple task. We present here a platform for the future use of designs of the TL through our homemade simulations. The TL is designed to be a component of the construction of an innovative accelerator at the Schlesinger Family Center for Compact Accelerators, Radiation Sources and Applications (FEL). We developed a three-dimensional space-frequency tool for the analysis of a radiation pulse. The total electromagnetic (EM) field on the edge of the source is represented in the frequency domain in terms of cavity eigenmodes. However, any pulse can be used regardless of its mathematical function, which is the key point of this work. The only requirement is the existence of the original pulse. This EM field is converted to geometric-optical ray representation through the Wigner transform at any desired resolution. Wigner's representation allows us to describe the dynamics of field evolution in future propagation, which allows us to determine an initial design of the TL. Representation of the EM field by rays gives access to the ray tracing method and future processing, operating in the linear and non-linear regimes. This allows for fast work with graphics cards and parallel processing, providing great flexibility and serving as future preparation that enables us to apply advanced libraries such as machine learning. The platform is used to study the phase-amplitude and spectral characteristics of multimode radiation generation in a free-electron laser (FEL) operating in various operational parameters.
构建用于宽可调谐广谱太赫兹辐射源的传输线（TL）并非易事。我们在此展示一个平台，通过自制模拟来供未来使用传输线设计。该传输线被设计为施莱辛格紧凑型加速器、辐射源及应用家族中心（FEL）创新加速器构建的一个组件。我们开发了一种用于分析辐射脉冲的三维空间频率工具。源边缘的总电磁场在频域中以腔本征模表示。然而，任何脉冲均可使用，无论其数学函数如何，这是此项工作的关键所在。唯一的要求是原始脉冲的存在。通过维格纳变换，该电磁场可在任何所需分辨率下转换为几何光学射线表示。维格纳表示使我们能够描述未来传播中场演化的动力学，从而使我们能够确定传输线的初始设计。用射线表示电磁场可采用射线追踪方法并进行未来处理，在线性和非线性区域中运行。这允许利用图形卡进行快速工作和并行处理，提供极大的灵活性，并作为未来的准备工作，使我们能够应用机器学习等先进库。该平台用于研究在各种运行参数下工作的自由电子激光（FEL）中多模辐射产生的相位 - 幅度和光谱特性。
