An ultrarelativistic electron beam passing through an intense laser pulse emits radiation around its direction of propagation into a characteristic angular profile. Here we show that measurement of the variances of this profile in the planes parallel and perpendicular to the laser polarization, and the mean initial and final energies of the electron beam, allows the intensity of the laser pulse to be inferred in way that is independent of the model of the electron dynamics. The method presented applies whether radiation reaction is important or not, and whether it is classical or quantum in nature, with accuracy of a few per cent across three orders of magnitude in intensity. It is tolerant of electron beams with broad energy spread and finite divergence. In laser-electron beam collision experiments, where spatiotemporal fluctuations cause alignment of the beams to vary from shot to shot, this permits inference of the laser intensity at the collision point, thereby facilitating comparisons between theoretical calculations and experimental data.

中文翻译：

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与模型无关的激光强度推断

穿过强激光脉冲的超相对论电子束沿其传播方向发射辐射，形成特征角轮廓。在这里，我们表明，在平行于和垂直于激光偏振的平面中测量此轮廓的变化以及电子束的平均初始能量和最终能量，使得可以以与电子动力学模型。提出的方法适用于辐射反应是否重要，本质上是经典反应还是量子反应，其强度在三个数量级上的精确度仅为百分之几。电子束具有宽的能量散布和有限的发散度。在激光-电子束碰撞实验中，