内爆磁压缩准等熵加载过程分析与实验验证

利用磁流体力学程序SSS-MHD模拟了炸药柱面内爆磁通量压缩发生器CJ-100装置的加载过程，讨论了各项装置参数的影响，结果表明装置可达到的峰值磁场值与初始磁场值成反比关系。设计了铁/铜夹层结构的样品靶，在该型装置上开展纯铁的准等熵加载实验。利用光子多普勒测速探头测量到6.43 km/s的样品靶自由面速度，在DT4铁中获得206 GPa的准等熵加载压力。铁材料的压力-比容曲线与理论等熵线基本重合，表明内爆磁压缩加载过程具有较高的等熵程度。

Analysis and experimental verification of quasi-isentropic loading process in explosive-driven magnetic flux compression

Explosive-driven magnetic flux compression generator is a device that converts the chemical energy of explosives into electromagnetic energy. It has attracted great attention in the field of high energy density physics due to its wide application and important development prospect in magnetic field compression and material high pressure loading. CAEP has conducted a lot of research on CJ-100 device, which can stably generate an axial magnetic field of about 700 T. In order to investigate the loading capacity of CJ-100 device, the loading process and the effects of various device parameters are discussed by using the one-dimensional magnetohydrodynamics program SSS-MHD. The results show that the peak magnetic field that can be reached by the device is inversely proportional to the initial magnetic field, and the size of sample target has a great influence on the loading pressure. A sample target of iron/copper layered structure was designed for quasi-isentropic loading experiment of pure iron. The initial inner radius of the sample target was 3 mm, and the thickness of both iron and copper layer was 1 mm. The experiment was carried out on CJ-100 device with an initial magnetic field of 5.5 T, atmospheric pressure of several hundred Pa and ambient temperature. The free surface velocity of the sample target of about 6.43 km/s was measured with Photonic Doppler Velocimetry probes. SSS-MHD program with proper material models provided curve of velocity versus time that agree well with the experimental measurement. Simulation then shows that a quasi-isentropic loading pressure of 206 GPa is obtained in DT4 iron. The p-v curve of iron material is basically coincided with the theoretical isentropic line, indicating that the loading process of CJ-100 has a high isentropic degree.