基于非线性纵向空间电荷振荡的可调窄带太赫兹辐射物理及技术问题研究

项目名称： 基于非线性纵向空间电荷振荡的可调窄带太赫兹辐射物理及技术问题研究

项目编号： No.11475097

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 颜立新

作者单位： 清华大学

项目金额： 120万元

中文摘要： 时间间隔～ps的相对论超短电子束序列，因其可在束团重复频率及若干次谐波频率处产生高能谱强度的窄带相干THz辐射，而成为当前加速器电子源的研究热点，如何产生大电荷量、高峰值流强的超短电子束序列，是提高THz辐射能谱强度的关键，深入开展相关研究，具有重要的科学意义和应用价值。区别于目前基本上只能产生低电荷量或低峰值流强的电子束序列的方法，本项目结合非线性纵向空间电荷振荡效应和束流压缩技术，探索一种新型的大电荷量、高峰值流强电子束序列的产生方法，并针对可调窄带高能谱强度THz辐射的产生，在清华大学基于光阴极微波电子枪的直线加速器平台上，深入开展实验研究。项目将在实验上证实大电荷量条件下（>1nC）的非线性纵向空间电荷振荡效应，实现基于紧凑加速结构的～kA量级高峰值流强的THz重复频率超短电子束序列产生技术，并利用这种电子束序列优化产生高能谱强度的窄带THz辐射，实现1～3THz的频谱可调。

中文关键词： 加速器；非线性纵向空间电荷振荡效应；超短电子束序列；太赫兹辐射

英文摘要： The relativistic ultrashort electron bunch train with ps spacing has attracted much attention as it has great applications in the prodcution of narrow-band coherent THz radiation at its repetition frequency and several harmonics with high spectral intensity. How to obtain high charge high peak current electron bunch trains plays the key role to improve its THz radiation spectral intensity. Unlike current methods which can only produce relatively low charge or low peak current bunch trains, in this proposal we are going to explore a novel approach which combines nonlinear longitudinal space charge oscillation effects with beam compression techniques to achieve high charge high peak current bunch trains. Experiments on tunable narrow-band THz production with such bunch trains will be performed on the photocathode-based linac facility at accelerator laboratory of Tsinghua Uniersity. In the project we will try to show nonlinear longitudinal space charge oscillations under conditions of high charge (>1nC), and realize the technique to achieve THz rep rate bunch trains with high peak current (～kA), with which to produce narrow band THz radiation which can be tuned in 1~3THz.

英文关键词： accelerator;nonlinear longitudinal space charge oscillation;ultrashort electron bunch train;THz radiation