利用2TW激光器产生具有超小归一化发散角的准单能电子束团的实验和模拟研究

Experiment and Simulation Study on Generation of Monoenergetic Electron with Ultra-small NDA from 2 TW Laser Facility

利用2TW、80fs激光脉冲和等离子体相互作用,产生了能量为(23.0±0.8)MeV、电量为6pC的准单能电子束。该电子束的归一化发散角只有92mrad,较之前激光等离子体加速领域所获得的实验结果至少小了5倍以上。二维数值模拟结果显示,此结果的产生归功于加速机制上从自调制激光尾场加速向激光尾场加速的平稳过渡。

Monoenergetic electron beams with the energy of （23.0±0.8） MeV and the charge of 6 pC were generated by using 2 TW and 80 fs laser pulses interacting with underdense plasmas. The beam＇s normalized divergence angle is merely 92 mrad, which is at least 5 times smaller than the published laser plasma acceleration experiment results. 2D simulation and experiment data analysis results show that the significant improvement is due to the smooth transfer from self modulated laser wakefield accelera- tion to laser wakefield acceleration.