ZR装置与Z箍缩负载耦合的全电路模拟

Full Circuit Model for Coupling ZR Facility With Z-Pinch Load

为掌握Z refurbishment(ZR)装置工作状态,方便开展Z箍缩相关实验的模拟分析,深入理解大型多路并联脉冲功率驱动器的工作原理,发展了ZR装置的全电路模型。基于有限差分方法编写了全电路模拟程序,分析了装置内部各结构组件的充放电过程,基于实验电流波形校验了关键组件的模型和参数,在此基础上研究了电磁脉冲的形成和传输过程。进一步针对典型的丝阵和套筒Z箍缩实验,将ZR装置全电路模型与负载0维内爆动力学模型耦合模拟,获得了负载半径、高度和质量等参数变化对内爆性能的影响规律。结果表明:充电电压为82 kV时,从驱动器电储能(18.9 MJ)到负载动能(1.2 MJ)的转换效率约为6%;在相同的充电电压和负载电极结构条件下,若负载都在各自优化设计的参数下工作,则应用于辐射源研究的丝阵负载线质量较小、初始半径较大及内爆速度较快;而应用于惯性约束聚变研究的套筒负载线质量较大、初始半径较小及内爆速度较慢;两种负载内爆动能十分接近。同时,内爆动能随负载高度和收缩比的增大而增大。

Z refurbishment(ZR)facility is the world’s largest pulsed power,which is operated by Sandia National Laboratory.To master the working state of the ZR facility,analyze the results of the latest Z pinch-related experiments,and deeply investigate the basic physics of large multi-module parallel pulse driver,a full circuit model for coupling the ZR facility with Z-pinch load is developed.The circuit equations of the full circuit model are numerically solved by using the finite difference method,and the charging and discharging process of each structural component in the device is analyzed.The model and parameters of the key structures are evaluated by comparing the simulated current waveforms with the experimental results,and the formation and transmission process of the electromagnetic pulse is studied.Further,the full circuit model of the ZR facility is coupled with zero dimensional implosion dynamic models of the Z-pinch load,typically including cylindrical metal wire arrays and liners.The influences of the radius,height,and mass parameters of the loads on the characteristics of implosion are analyzed.The results show that the transformation efficiency from the driver electrical energy of 18.9 MJ to the load kinetic energy 1.2 MJ is about 6%under 82 kV charging voltage.The characteristics of the wire-array loads have been compared with the liner loads at the same working status of the driver.In general,the wire array load applied to the research of the radiation source has a smaller mass,larger initial radius,and faster implosion speed.However,the liner load line used in inertial confinement fusion research has a larger mass,smaller initial radius,and slower implosion speed,and the two loads are very close to each other.The kinetic implosion energy increases with the increase of load height and contraction ratio.