双层丝阵Z箍缩电流分配实验研究

Experimental study on current division of nested wire array Z pinches

负载内外层电流分配是决定双层丝阵Z箍缩内爆动力学模式的关键因素.在"强光一号"装置上,利用微型磁探针系统定量测量了双层钨丝阵三个重要径向位置点的电流,获得了其在驱动电流开始上升至驱动电流达到峰值之前20ns这一阶段内的时间演化行为.实验使用的双层钨丝阵负载高度为20 mm、单丝直径为3.8μm、内/外层丝阵直径分别为8 mm/16 mm.对比了内/外层丝根数分别为42/21和21/42时电流分配的差异.结果表明:驱动电流上升过程中,内外层丝阵的电流均逐步增大,外层丝阵电流份额逐渐减小,而内层丝阵电流份额逐渐增大;内层丝阵最大电流份额未超过50%;内/外层丝根数为21/42的负载外层电流较大.

The current division between the inner and the outer arrays is one of the key factors that impact the implosion dynamics and modes of nested wire array. This paper presents the first quantitative measurements of current division for nested wire array Z pinch on the Qiang Guang-I pulsed power facility. In experiments, the nested wire arrays, made of 3.8 gm-diameter tungsten wires, were 20 mm in height and 8 mm/16 mm in diameter for inner/outer array. Measurements for loads consisting of 42/21 wires in inner/outer array were compared with that of 21/42 in inner/outer array. Data of current versus time at various radial positions were obtained using magnetic probes until 20 ns before the current peak. Results show that the currents in inner and outer arrays increase during the rise of the driving current, the proportion of current in outer array decreases and that in inner array increases, while the current in outer array, for loads with 21/42 wires in inner/outer array, was larger than those with 42/21 wires in inner/outer array.