强激光脉冲中高能电子辐射的时间演化研究

Time Evolution of High-Energy Electron Radiation in Intense Laser Pulses

为了研究圆偏振强激光脉冲中高能电子辐射随时间的演化,在拉格朗日方程和电子能量方程的基础上,构建了高能单电子与强激光脉冲相互作用的模型,采用MATLAB对此过程进行模拟和计算,得到了电子辐射的空间分布随时间演化的仿真图像。结果表明,受圆偏振紧聚焦强激光脉冲作用的电子所发出的电磁辐射能量会随时间由外而内呈现涡旋状的空间分布,且在约1000 fs后集中在中心;辐射向内集中的速度会随时间逐渐放缓。此外,单位立体角辐射能量的最大值也会随时间递增,且变化速度先增大后减小。在450 fs附近,辐射能量到达平台期,此后继续缓慢增加,直至1000 fs后稳定在1.18×10^(-12)J/cm^(2)。此结果表明,可以通过控制电子与激光相互作用的时间,更快得到符合实验要求特性的电子辐射。

In order to study the time evolution of the high-energy electron radiation in the circularly polarized intense laser pulse,a model of the interaction between the high-energy single electron and the intense laser pulse is constructed on the basis of the Lagrangian equation and the electron energy equation.Simulations and calculations are carried out through MATLAB to obtain simulated images of the time evolution of the spatial distribution of electron radiation.The results show that the electromagnetic radiation energy presents a vortex-like spatial distribution with time,and concentrates in the center after about 1000 fs;the speed of the radiation concentrating inward gradually slows down over time.In addition,the maximum value of the radiant energy per unit solid angle will also increase with time,and the rate it changes first increases and then decreases.Around 450 fs,the radiation energy levels off,then continues to climb slowly until it stabilizes at 1.18×10^(-12)J/cm^(2)after 1000 fs.Thus,ideal electron radiation can be obtained more easily by controlling the interaction time between electrons and laser light.