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 optimized 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 a median photon energy of 20 keV, $>6\times {10}^8\mathrm{photons}$ above 1 keV per shot, and a peak brightness of $3\times {10}^{22}\text{photons}{\mathrm{s}}^{-1}\mathrm{mra}{\mathrm{d}}^{-2}{\mathrm{mm}}^{-2}$ $(0.1\%\mathrm{BW}{)}^{-1}$.

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，可以预测由激光尾场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射线束的中值光子能量为20 keV，$>6\times {10}^8\mathrm{光子}$ 每次拍摄高于1 keV，峰值亮度为 $3\times {10}^{22}\text{光子}{\mathrm{s}}^{-\mathrm{1个}}\mathrm{姆拉}{\mathrm{d}}^{-2}{\mathrm{毫米}}^{-2}$ $（0.1％\mathrm{体重}{）}^{-\mathrm{1个}}$。