基于热峰模型的单粒子效应模拟研究

Simulation of Single Event Effect by a Thermal Spike Model

单粒子效应是航天电子器件失效的重要原因,研究其物理过程对航天电子器件寿命预测、器件抗辐照加固有着重要的意义。现有的模型多从线性能量沉积的角度来解释单粒子翻转,因此无法解释单粒子效应地面实验模拟过程中的温度效应。建立了一个新模型,从高能带电离子与材料相互作用的物理过程出发,通过解三维的热扩散方程,计算出能量在材料中沉积、交换、扩散,得到电子和晶格温度的空间分布以及时间演化过程。推断出离子辐照过程中导致的自由电子浓度和收集电荷随LET的变化关系。此模型解释了单粒子效应中随着器件温度升高,单粒子效应截面增加的现象。

Single event effect (SEE) is an important reason that induces failures in space electronic components. Explanations of physical process are important to life evaluation of electronic devices and radiation hardening. Many models, in which cross section of SEE was related to the linear energy transfer (LET)、were presented. However, according those models, temperature effects could not be explained. A new model, which is based on interact ions of high-energy ion with material, is proposed. This model is employed to calculate the energy deposition, exchange and diffusion in material. The temperatures electron and lattice are obtained from thermal diffusion equations. Evolutions of electron and lattice with space and time are presented. The model suggested the concentration of free electrons and total collected charge induced by irradiation of ions were function of LET. The model explained an experimental effect that the cross sections of SEE increased with the temperature of device.