Quantum electrodynamics predicts x-ray diffractions under a high-intensity laser field via virtual charged particles, and this phenomenon is called as vacuum diffraction (VD). In this paper, we derive a new formula to describe VD in a head-on collision geometry of an XFEL pulse and a laser pulse. A wavefront curvature of the XFEL pulse is newly considered in this formula. With this formula, we also discuss the curvature effect on VD signals based on realistic parameters at SACLA XFEL facility.

中文翻译：

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强激光场引起的 X 射线真空衍射曲率效应的新估计

量子电动力学通过虚拟带电粒子在高强度激光场下预测 X 射线衍射，这种现象称为真空衍射 (VD)。在本文中，我们推导出了一个新公式来描述 XFEL 脉冲和激光脉冲正面碰撞几何中的 VD。该公式中新考虑了 XFEL 脉冲的波前曲率。使用这个公式，我们还讨论了基于 SACLA XFEL 设施的实际参数对 VD 信号的曲率影响。