Laser-wakefield acceleration has been demonstrated to be a promising technique for compact electron accelerators. However, it is still challenging to achieve high-quality 100-MeV electron bunches of subfemtosecond duration with current techniques. Here, we present and numerically demonstrate an efficient scheme to produce such high-energy tunable ultrashort electron bunches, which is achieved by the use of a nonlinear wakefield driven by a terawatt few-cycle laser pulse in a tailored plasma channel. With the driving laser pulse energy of 25 mJ only, the resulting electron bunch can reach 101 MeV with 7.8-pC charge, approximately 4 mrad divergence, approximately 3% energy spread, energy efficiency above 3%, and a duration of hundreds of attoseconds. As such laser pulses may be obtained with a kilohertz repetition rate and high stability, our scheme could be interesting for ultrafast science and accelerator community.

中文翻译：

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兆瓦级短周期激光脉冲产生100 MeV阿秒电子束

激光尾场加速已被证明是紧凑型电子加速器的一项有前途的技术。然而，利用现有技术来实现亚飞秒持续时间的高质量100 MeV电子束仍然具有挑战性。在这里，我们提出并数值演示了一种有效的方案，以生产这种高能可调节的超短电子束，这是通过在定制的等离子通道中使用兆瓦级数周期激光脉冲驱动的非线性尾波场来实现的。仅使用25 mJ的驱动激光脉冲能量，所产生的电子束在7.8 pC电荷，大约4 mrad的发散度，大约3％的能量散布，超过3％的能量效率以及数百阿秒的持续时间下可以达到101 MeV。由于可以以千赫兹的重复频率和高稳定性获得这样的激光脉冲，