“阳”加速器磁驱动平面飞片实验和速度计算校验

脉冲功率驱动源作为磁驱动加载的重要手段,通过调整其电路参数可调节负载电流波形,实现对样品无冲击准等熵加载。在"阳"加速器上,开展了一系列轴对称结构和带状结构构型的磁驱动平面飞片发射实验,电极材料采用不锈钢和LY-12铝。实验中测量了进入负载的电流历史和电极后自由面速度历史,并通过时序控制将两者时间关联起来。本文以测量到的电流历史数据为基础,引入负载电流分布系数,并结合已知的LY-12铝的状态方程数据,计算电极后自由面速度历史和飞片速度历史。通过实验测量自由面速度历史校验负载各个位置的电流分布系数。另外,基于装置参数和实验数据确定了考虑负载电感变化的装置等效电路模型,形成了计算样品压力加载历史和电极后自由面速度历史估算程序。此外,初步分析不同厚度电极的自由面速度历史,获取了电极材料的准等熵加载波剖面信息,观察到一系列准等熵加载下材料动力学性能引起的物理现象。

Experiments and velocity validation of magnetically driven flyer plates on “Yang” accelerator

A series of magnetically driven flyer plates experiments were performed on “Yang” accelerator with electrode material of LY-12 alloy and stainless steel. By changing the module parameters, we can acquire the desired current waveform for launching flyer plates shocklessly on stripline and coaxial load configurations. Considering the efficiency factor of current history, we calculated the free-surface velocity and flyer velocity history, which were in good agreement with the measured results. In addition, with current calculation model which considered variable load inductance, we calculated load current and flyer velocity which were also in agreement with the measured results. In this way, we could design an optimized load configuration that minimized the axial variation of the stripline’s magnetic pressure. Furthermore, we can predict sample stress history and flyer velocity on more powerful pulse facility.