Bunch length measurement at Tsinghua Thomson scattering X-ray source

The length of electron beam from a photocathode RF gun is determined by a spectrometer, according to the relative energy spread induced by the bunch length during the acceleration in a linac. For a photocathode RF gun, different laser injected phase and beam charge are studied. The compression is changed for the different laser phases, as from 10° to 30°, and the bunch length is lengthened due to the strong longitudinal space charge force, caused by the increased charge.     

激光聚变冲击点火物理特性研究

冲击点火是一种新型的惯性约束聚变点火方案,该点火方案具有低点火能量阈值、高增益和较好的流体力学稳定性等优点.本文针对冲击点火的物理特性进行理论分析和数值模拟.首先以一维平板模型对冲击波碰撞的物理过程进行理论研究和分析;然后通过辐射流体力学数值模拟对冲击点火的物理特性进行研究,验证理论分析结果,并考察冲击加载时间对点火的影响. 关键词： 冲击点火 冲击波碰撞 辐射流体力学模拟     

Multislit-Based Emittance Measurement of Electron Beam from a Photocathode Radio-Frequency Gun

Measurement of emittance for a space-charge dominated electron beam from a photocathode rf gun is performed by employing the multislit-based method at Accelerator Laboratory of Tsinghua University. We present the design considerations on the multislit system and the experimental results, with special attention to the study of space charge induced emittance growth. The experimental results are in reasonable agreement with the PARMELA simulations.     

太赫兹自由电子激光的受激饱和实验

中国工程物理研究院基于半导体光阴极高压直流电子枪和超导直线加速器的高平均功率太赫兹自由电子激光达到了受激饱和,并实现了太赫兹光输出频率可调.在1.99,2.41和2.92 THz三个频率点上进行测试,测得太赫兹宏脉冲内平均功率大于10 W,最高达17.9 W.本文介绍了太赫兹自由电子激光装置的主要组成部分及受激饱和实验的结果.