金属丝电爆炸过程中等离子体光辐射时空演化行为研究

Electrical explosion of a wire driven by a pulsed current is a conventional method for generating plasmas with relatively high temperature and density, pulsed electromagnetic radiation, and strong shock waves, which is widely applied in national defense and energy field. Specifically, optical emission from the wire-explosion plasma (plasma radiation) is significant for the ignition technology of energetic materials and the research on the properties of non-ideal plasmas. However, little attention has been paid to the optical emission previously, and the key problems including optical emission characteristics, influence factors, and physical mechanisms are not fully understood yet. Therefore, starting with the optical emission phenomenon of wire explosions in vacuum and air, this project plans to conduct an investigation on spatial-temporal evolution behaviors of the plasma radiation during an electrical wire explosion. Based on the plasma diagnostic system with a high spatial-temporal resolution, this project is to explore the physical process of the electrical breakdown stage and the evaluation of the key plasma parameters. Subsequently, characteristics and generation processes of the optical emission will be researched. Moreover, effects from the ambient medium on the plasma state and optical emission are to be studied and obtained. Finally, according to optical emission characteristics, the parameter-regulation method of the optical emission is to be concluded and proposed. By performing this project, a deep insight into the evolution of plasma radiation can be provided and the mechanisms of ambient medium’s effects on optical emission can also be clarified. In addition, theories and applications of the wire explosion can be promoted, laying a solid foundation for the wire-explosion ignition of energetic materials.

脉冲电流驱动金属丝电爆炸可产生具有较高温度、密度的等离子体，并伴随脉冲电磁辐射、强冲击波等效应，广泛应用于国防与能源领域；其中，电爆炸等离子体的光辐射对驱动含能材料起爆以及探究非理想等离子体性质具有重要意义。然而，人们未对电爆炸等离子体光辐射给予足够重视，对光辐射特性、影响因素与物理机制的认识尚不清晰。对此，本项目拟从真空与空气介质中电爆炸的光辐射现象切入，开展金属丝电爆炸过程中等离子体光辐射时空演化行为与介质氛围影响机制研究。基于高时空分辨的光学诊断系统，探究电爆炸击穿过程与等离子体关键参数演化规律，研究等离子体光辐射时空演化特征与产生过程，研究介质氛围对等离子体状态的影响与光辐射的吸收作用，归纳等离子体光辐射特性与参数调控方法。通过研究，可深入认识电爆炸等离子体光辐射行为演化，明确介质氛围对光辐射的影响机制，丰富和发展金属丝电爆炸理论与应用，为含能材料起爆提供坚实的理论基础和科学依据。

脉冲电流驱动金属丝电爆炸可产生具有较高温度、密度的等离子体，并伴随脉冲电磁辐射、强冲击波等物理效应。该项目开展了电爆炸等离子体光辐射时空演化行为及介质氛围影响机制研究，深入认识了电爆炸击穿过程与等离子体关键参数演化行为，获得了等离子体光辐射的时空演化特征与产生过程，明确了介质氛围对等离子体及其光辐射的作用机制；面向电爆炸驱动含能材料的工程实际需求，归纳部分等离子体和光辐射参数调控和优化方法。代表性研究成果如下：（1）完善了微秒尺度电爆炸多物理诊断方法，完成了放电-成像-记录系统之间的同步，实现了电-光-力多物理参量同步诊断；在数值计算方面，完善了电爆炸过程等离子体（磁）流体计算以及爆炸过程的显示动力学分析模型，计算了电爆炸等离子体系统的弛豫特性。（2）基于电-热不稳定性理论，首次发现分层电爆炸产物击穿新模式，提出了分层金属热蒸汽的热-电联合击穿模型，深入剖析了金属蒸汽和等离子体相互作用的物理图像，给出了电爆炸等离子体局域加热机理和非均匀多层冲击波产生机制。（3）系统研究了电爆炸等离子体从温稠密向类电弧过渡过程，明晰了等离子体及其辐射参数的动态演变行为，率先提出了决定电爆炸强度的本征参数——系统磁能，归纳了电物理参数和辐射、动力学参数之间的关联性，精准预测了不同驱动能量下电爆炸物理效应的变化趋势，并首次比较了电爆炸和金属电弧在热力学和输运参数方面的异同。（4）深入研究了流体介质对电爆炸等离子体的影响，首次报道了跨气-液界面的电爆炸现象，有力推进了电爆炸技术在流体物理研究中的应用；明确了气相和液相介质对电爆炸等离子体作用方式的差异，研究了不同介质条件下爆炸产物冷却过程和微观特征的关联性。研究结果有力揭示了流体介质中电爆炸等离子体光辐射行为演化的物理图像，丰富和发展了金属丝电爆炸理论与应用，为含能材料起爆技术、爆炸效应实验室模拟等应用提供坚实的理论基础和科学依据。