We report on the stable and continuous operation of a kilohertz laser-plasma accelerator. Electron bunches with 2.6 pC charge and 2.5 MeV peak energy were generated via injection and trapping in a downward plasma density ramp. This density transition was produced in a specially designed asymmetrically shocked gas jet. The reproducibility of the electron source was also assessed over a period of a week and found to be satisfactory with similar values of the beam charge and energy. Particle in cell simulations confirm the role of the shock and the density transition in the electron injection mechanism. These results show that the reproducibility and stability of the laser-plasma accelerator are greatly enhanced on the long-term scale when using a robust scheme for density gradient injection.

中文翻译：

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演示千赫激光等离子体加速器的长期稳定运行

我们报告了千赫激光等离子体加速器的稳定和连续运行。通过注入和俘获在向下的等离子体密度斜坡中产生具有2.6 pC电荷和2.5 MeV峰值能量的电子束。这种密度变化是通过特殊设计的非对称冲击气体射流产生的。还对电子源的可重复性进行了为期一周的评估，发现在类似的电子束电荷和能量值下令人满意。电池模拟中的粒子证实了冲击和密度转变在电子注入机理中的作用。这些结果表明，当使用鲁棒的密度梯度注入方案时，激光等离子体加速器的重现性和稳定性在长期规模上得到了极大的提高。