High-altitude electromagnetic pulse (HEMP) generated by the photons from nuclear explosions is a threat to electronic and power systems. During the generation of HEMP, besides the gamma rays released directly by the nuclear devices, the scattered gamma rays can also produce recoil electrons that contribute to the Compton current and further conduction current. Therefore, the gamma-ray model containing both direct and scattered gamma is more accurate to be used in the simulation of HEMP environments. In this article, the modified gamma-ray model based on single-scattering approximation which considers the effects of scattered gamma is presented and the results of the modified model and the traditional prompt-gamma-only model are compared. It is concluded that the scattered gamma rays have little effect on the peak value and rising edge of HEMP. However, the scattered gamma rays influence the electric field at the end of early-time HEMP greatly. This method is also an approach to the scattered gamma component of intermediate-time HEMP.

中文翻译：

---

使用改进的散射伽马模型模拟高空核电磁脉冲

由核爆炸产生的光子产生的高空电磁脉冲 (HEMP) 对电子和电力系统构成威胁。在HEMP的产生过程中，除了核装置直接释放的伽马射线外，散射的伽马射线还可以产生反冲电子，有助于康普顿电流和进一步的传导电流。因此，包含直接和散射伽马的伽马射线模型更适合用于模拟 HEMP 环境。本文提出了考虑散射伽马效应的基于单散射近似的修正伽马射线模型，并比较了修正模型和传统的仅瞬发伽马模型的结果。结论是散射伽马射线对HEMP的峰值和上升沿影响不大。然而，散射的伽马射线对早期HEMP结束时的电场影响很大。该方法也是对中间时间HEMP的散射伽马分量的一种处理方法。