Picksley A, Stackhouse J, Benedetti C, Nakamura K, Tsai H E, Li R, Miao B, Shrock J E, Rockafellow E, Milchberg H M, Schroeder C B, van Tilborg J, Esarey E, Geddes C G R, Gonsalves A J
<a href="https://ror.org/02jbv0t02">Lawrence Berkeley National Laboratory</a>, Berkeley, California 94720, USA.
<a href="https://ror.org/01an7q238">University of California</a>, Berkeley, California 94720, USA.
Phys Rev Lett. 2024 Dec 20;133(25):255001. doi: 10.1103/PhysRevLett.133.255001.
We measure the high-intensity laser propagation throughout meter-scale, channel-guided laser-plasma accelerators by adjusting the length of the plasma channel on a shot-by-shot basis, showing high-quality guiding of 500 TW laser pulses over 30 cm in a hydrogen plasma of density n_{0}≈1×10^{17} cm^{-3}. We observed transverse energy transport of higher-order modes in the first ≈12 cm of the plasma channel, followed by quasimatched propagation, and the gradual, dark-current-free depletion of laser energy to the wake. We quantify the laser-to-wake transfer efficiency limitations of currently available petawatt-class lasers and demonstrate via simulation how control over the laser mode can significantly improve beam parameters. Using 21.3 J of laser energy, and triggering localized electron injection, we observed electron bunches with single, quasimonoenergetic peaks up to 9.2 GeV with charge extending beyond 10 GeV.
我们通过逐次调整等离子体通道的长度，测量了米级通道引导激光等离子体加速器中高强度激光的传播情况，结果表明，在密度(n_{0}≈1×10^{17} cm^{-3})的氢等离子体中，500太瓦的激光脉冲在30厘米的距离上实现了高质量引导。我们观察到，在等离子体通道的前约12厘米内高阶模的横向能量传输，随后是准匹配传播，以及激光能量逐渐无暗电流地耗尽到尾流中。我们量化了当前可用拍瓦级激光器的激光到尾流的转换效率限制，并通过模拟证明了对激光模式的控制如何显著改善束流参数。使用21.3焦耳的激光能量并触发局部电子注入，我们观察到了电荷延伸超过10GeV、具有高达9.2GeV的单个准单能峰的电子束团。
