高能电子在强激光场中的同步辐射获得超短X射线脉冲

 研究了逆流相对论高能电子与强激光脉冲相互作用的同步辐射过程，当电子具有合适的初速度且传播方向与激光的传播方向相反时，电子在激光脉冲中心作圆周运动。由于电子的运动半径比传统同步辐射环中电子的运动半径小几个数量级，因此电子的辐射能量大大增加。研究发现此过程可以获得阿秒和泽秒X射线脉冲；同时发现随着入射电子初能量的增加和激光能量的增强，获得X射线脉冲脉宽越来越短，强度越来越大。这使得激光同步辐射可以成为一种强大的短波长短脉宽的辐射光源。

Ultrashort X-ray pulses emitted from laser-field synchrotron radiation

Electron with an appropriate initial velocity injected into an oncoming, ultra-intense circularly polarized laser pulse will execute circular relativistic motion at the peak of laser pulse. The circulating electron then radiates in the same manner as that in the storage ring of a conventional synchrotron source. Owing to the extremely small orbit radius, the laser-field synchrotron radiation thus generated is an attosecond or zeptosecond X-ray pulse. The pulse width of the scattered radiation decreases and the power of the scattered radiation increases with increasing the intensity of the laser pulse and the electron’s initial energy. The unique feature makes the laser-field synchrotron radiation a promising synchrotron radiation source with short wavelength and short duration.