Production of a femtosecond X-ray pulse using an electron beam driven by laser-plasma acceleration and its applications to time-resolved X-ray diffraction

我们已经证明了通过激光康普顿散射(LCS)产生X射线脉冲，这是飞秒激光脉冲从准单能电子束(QME)上散射出来的，在激光-等离子体加速的驱动下具有窄的能量分布。用一束能量为60 MeV、含70个pC电子的准分子束产生发散角约为5mrad的准直X射线束。X射线光子数估计为每脉冲2E7，这与使用射频加速器的LCS X射线源所获得的结果相当。利用QME束的测量特性进行了数值模拟，估算出X射线的峰值能量为60keV。还提出了X射线脉冲宽度约为100fS的结论。

We have demonstrated X-ray pulse generation via laser Compton scattering (LCS), which is the scattering of a femtosecond laser pulse off a quasi-monoenergetic electron (QME) beam with a narrow energy spread driven by laser-plasma acceleration. A well-collimated X-ray beam with a divergence angle of approximately 5 mrad is produced using a QME beam containing 70 pC electrons with an energy of 60 MeV in the monoenergetic peak. The X-ray photon number is estimated to be 2E+7 per pulse, which is comparable to that achieved in LCS X-ray sources using rf accelerators. The peak energy of the X-rays is estimated to be 60 keV by a numerical simulation using the measured characteristics of the QME beam. It is also suggested that the X-ray pulse duration is on the order of 100 fs.