We show that the properties of the electron beam and bright x-rays produced by a laser wakefield accelerator can be predicted if the distance over which the laser self-focuses and compresses prior to self-injection is taken into account. A model based on oscillations of the beam inside a plasma bubble shows that performance is optimised when the plasma length is matched to the laser depletion length. With a 200 TW laser pulse this results in an x-ray beam with median photon energy of , $>6\times {10}^8$ photons above per shot and a peak brightness of $\unit[3 \times 10^{22}]{photons s^{-1}mrad^{-2}mm^{-2} (0.1% BW)^{-1}}$.

中文翻译：

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来自不断发展的激光尾波加速器中等离子体气泡的明亮X射线辐射

我们表明，如果考虑到激光在自注入之前自聚焦和压缩的距离，可以预测由激光尾波加速器产生的电子束和明亮的X射线的特性。基于等离子气泡内部光束振荡的模型表明，当等离子长度与激光耗尽长度匹配时，性能将得到优化。如果使用200 TW的激光脉冲，则产生的X射线束的光子能量中位数为$>6\times {10}^8$光子高于每次拍摄，峰值亮度为$ \ unit [3 \ times 10 ^ {22}] {photons s ^ {-1} mrad ^ {-2} mm ^ {-2}（0.1％BW）^ {- 1}} $。