飞秒脉冲激光辐照典型电子器件的径迹演化规律及单粒子效应

The physical essence of single event effects induced by high energy particle radiating electronic devices of spacecraft in orbit is a key and outstanding problem that has not been solved completely in the international aerospace field. In the process of high energy particle radiating electronic devices, the track evolution of charge and particle in the packaging of electronic device is the microscopic manifestation of photoionization and thermal effect, and revelation of the physical process will provide a breakthrough for solving the aforementioned problem. The method of combining experiment with theoretical analysis will be adopted and evolutionary process of charge track and laser incident track generated by the femtosecond pulsed laser irradiating packaging of typical electronic devices will be studied systematically by using femtosecond pulsed laser as a radiation source to simulate high energy particles source. The key point is to revealing correlation laws of laser irradiation condition, thickness of device packaging and track evolutionary characteristics of charge and laser in the packaging. By measuring single event effects induced by laser irradiating packaging with the same irradiation condition and packaging thickness of corresponding device, the mathematical and physical models on laser irradiation condition，packaging thickness of corresponding device, evolutionary characteristics of charge migration, laser tracks and single event are established, and then the influence laws of irradiation condition of femtosecond pulsed laser, track evolution of packaging of electronic devices and single event effects which are measured with the same packaging thickness of corresponding electronic device are revealed, the research results will provide valuable references for improving anti radiant ability of typical electronic devices in spacecraft and the risk assessment for spacecraft in orbit.

高能粒子辐射在轨航天器电子器件诱发单粒子效应的物理本质是国际航天界仍未很好解决的关键突出问题。高能粒子入射电子器件过程中电荷和粒子在器件封装中的径迹演化是光致电离和热效应的微观表现，该物理过程的揭示必将为该问题的解决提供突破口。本项目采用实验和理论分析相结合的方法，利用飞秒脉冲激光作为模拟高能粒子的辐射源，系统研究飞秒脉冲激光辐照典型电子器件封装过程中电荷径迹和激光入射径迹的演化过程。重点揭示激光辐照条件、器件封装厚度与电荷和激光在封装中径迹演化特征的关联规律。通过对相同辐照条件、对应封装厚度下典型电子器件诱发单粒子效应的实验测量，建立激光辐照条件、对应器件封装厚度与电荷迁移和激光径迹的演化特征及单粒子效应的数理模型，进而揭示飞秒脉冲激光辐照条件、电子器件封装的径迹演化与对应器件封装厚度下典型电子器件单粒子效应的关联规律，为航天器典型电子器件的抗辐射能力提升和在轨风险评价提供有价值的参考。

为阐明空间高能粒子辐射航天器电子器件诱发单粒子效应的物理本质，利用飞秒脉冲激光辐照模拟空间高能粒子辐射，开展了飞秒脉冲激光辐照航天器典型电子器件的电荷径迹、激光入射径迹以及单粒子效应研究。通过构建飞秒脉冲激光辐照电子器件产生的电荷径迹以及激光入射径迹测量系统、激光辐照电子器件温度分布测量系统、应力应变测量系统、热电效应以及单粒子效应测量系统，对不同激光辐照条件下电子器件外部封装及核心区典型材料（单晶硅）辐照产生的电荷演化特征、温度分布特征、激光入射径迹的温度演化和烧蚀形貌特征、靶板所受径向和环向应力、不同温度梯度条件下核心区典型材料的热电效应以及单粒子效应进行了实验研究；同时，基于激光支持爆轰波传播理论对飞秒脉冲激光作用电子器件产生爆轰波的传播过程、飞秒脉冲激光辐照电子器件产生的热效应以及单粒子效应进行了数值模拟。实验测试与理论计算结果表明：飞秒脉冲激光辐照铁电存储器封装与辐照电子器件核心区典型材料（单晶硅）产生的电荷演化特征表现为激光作用初始时刻电荷量最大，不同辐照条件下产生电荷量的峰值为3.48×10-12C；激光辐照产生的温度场近似为高斯分布，由此产生的热应力随激光作用时间的增加而增加；激光烧蚀产生的熔融颗粒在热应力作用下反向抛射，因此激光烧蚀径迹表现为入口处的烧蚀半径大于靶板内部的激光烧蚀半径。综合上述结果分析得出：激光辐照铁电存储器的初始时刻封装前表面激光作用区域迅速升温同时产生电子形成光致电离，光电效应生成的电子空穴对漂移、扩散，经过器件的灵敏节被收集，当载流子数量超过临界值后，在器件电路的输出端产生瞬态脉冲信号并传播至后续电路中，发生单粒子效应；激光脉冲频率越高，靶板温升速度越快，发生单粒子效应的时间越短；单粒子效应出现的时间随激光频率的升高呈指数下降。本项目研究成果将为进一步揭示单粒子效应产生的物理机制、提高航天器电子器件的抗辐射能力提供有价值的参考。