We theoretically investigate spectra of emitted light in nonlinear Thomson backscattering, which is generated during the head-on collision of the electron and the tightly focused circularly polarized laser pulse. With numerical analysis, a novel approach of generating quasi-monochromatic x-rays is obtained. By properly setting the electron–laser interaction point, limiting the laser intensity, and increasing pulse duration, the emission spectral bandwidth would be effectively narrowed without reducing the radiant energy of the electrons. In the end, the optimal situations for obtaining the quasi-monochromatic x-ray source are presented.

中文翻译：

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电子与紧密聚焦的激光脉冲碰撞产生的准单色辐射的光谱形状

我们从理论上研究了非线性 Thomson 背向散射中发射光的光谱，这是在电子和紧密聚焦的圆偏振激光脉冲正面碰撞期间产生的。通过数值分析，获得了一种产生准单色 X 射线的新方法。通过适当设置电子-激光相互作用点、限制激光强度和增加脉冲持续时间，可以在不降低电子辐射能量的情况下有效地缩小发射光谱带宽。最后给出了获得准单色X射线源的最佳条件。