超强激光与固体靶相互作用能够在靶后鞘层区域自洽地激励太赫兹辐射。该物理现象与超热电子产生与输运、靶后静电鞘层演化以及离子加速等系列物理过程紧密相关。深入理解和掌握其内部物理机制对于加速离子物理过程的诊断分析以及实验室条件下可重复性太赫兹源实现技术具有重要意义。本项目拟运用理论分析、物理建模和数值模拟研究等方法，针对激光驱动固体靶并激励太赫兹辐射物理过程开展深入研究。建立描述鞘层电场作用下相对论电子非线性运动行为和加速辐射场物理特征的理论分析模型，获得太赫兹辐射强度、频谱分布与鞘层电场强度和超热电子温度等物理参数的定标关系；模拟研究激光固体靶相互作用激励太赫兹辐射物理过程，阐明鞘层演化、离子加速以及电子回流振荡等过程对太赫兹辐射行为和特征的影响以及内在的物理规律。在确定靶后辐射太赫兹主要物理机制的基础上，提出优化物理方案并开展有针对性的验证实验研究。

It has been observed in experiments the self-generated strong THz pulses is emitted from the rear surface of a solid target during relativistic laser-solid interaction. It is linked to the acceleration and propagation of hot electrons, the evolution of the target normal sheath and the dynamic of ion acceleration process at the rear surface of the laser-irradiated target. This opens a perspective for the application of THz radiation detection for on-site diagnostics of particle acceleration in laser-produced plasmas and the design of repeatable Thz source in laboratory. In this work, theoretical modeling and particle-in-cell simulations will be used to study the details of the emission originates from a micron-scale plasma sheath at the rear surface of the target, which mostly emitted at large angles to the target normal in experimental results. The strong and intriguing correlation between THz emission and rear-surface ion acceleration will be discussed and derived. The optimized experimental configuration will be proposed and tested in next round of experiments.