将时域传输线模型与漂移扩散模型相结合，提出一种耦合数值计算方法，研究计算了带二极管负载的电缆在X射线辐照下的瞬态响应。该耦合数值计算方法首先利用时域传输线模型计算电缆在X射线辐照下的各节点电参数，然后将得到的终端节点的电压代入漂移扩散模型中求解二极管的内部参数与偏置电流，最后将得到的偏置电流代入到下一时间步的传输线模型中继续进行计算。该方法能够直接反映出电缆在X射线辐照下的瞬态响应与所连接的负载状态改变之间的耦合关系，利用该方法求解X射线辐照简单电子系统的典型算例，计算结果表明，X射线辐照下，同轴电缆上各处的响应电流会随着PIN二极管状态的改变而发生明显变化，与理论分析相符合，耦合模型适用于此类问题。

This paper introduces the transmission line method which is used to calculate the coaxial response to Xray and the driftdiffusion method which is used to calculate the parameters of semiconductor devices. Combining the transmission line method with the driftdiffusion method, we calculated the Xray transient response of coaxial line with PIN diode. The coupled model shows the relation of coaxial line’s response to pulsed Xray and the diode’s status. An example was calculated using the coupled model, the implications of the data were discussed in detail. The coupled model can be used in calculating the responses of coaxial lines with other semiconductor devices to pulsed Xray.