“强光一号”锥形丝阵内爆特性研究

在强光一号装置开展小倾角单层锥形钨丝阵实验, 获得了锥形丝阵在消融阶段, 拉链内爆阶段和滞止阶段的辐射参数和辐射图像. 消融阶段的物理图像映证了使用火箭模型对锥形丝阵消融过程及先驱等离子体形成的分析. 结合分幅像、针孔像和条纹像, 解释了锥形丝阵在内爆箍缩阶段阴极部分首先发生内爆并产生硬X射线成分的原因. 观察到的锥形丝阵的拉链内爆速度达到2.59× 10⁷ cm/s, 拉链内爆及滞止的持续时间达到40 ns, 远大于相近尺寸的柱形丝阵. 通过特殊构型丝阵内爆特性的研究, 为进一步验证基于柱形丝阵建立的Z-pinch理论模型, 完善MHD模型的普适性提供必要的实验数据.

Implosion characteristics of conical wirearray Z pinches on "Qiangguang1" facility

Implosion and radiation characteristics of conical wire array in different regimes of implosion are investigated at the 1 MA Qiangguang-1 facility by X-ray self-emission diagnostics. Experimental results show that the shape of precursor plasma is also conical. The initial implosion takes place near the cathode by a stronger Lorenz force, forming a triangle-like structure that produces harder X ray. The current crossing the bubble in the front of the wire array near the anode persists in persist ablating, thereby leading to a zippered stagnation. The initial implosion of a bubble near the cathode is followed by the implosion zippering upwards as the zipper implosion speed is 2.59× 10⁷ cm/s. The results shows that the conical array has a broader X-ray power pulse than cylinderical wire array due to the zippered stagnation and zippered implosion of the array. The study of implosion characteristics of specialized axis symmetric wire array Z-pinch-like conical wire array can provide a valuable test bed for understanding the regime of implosion as well as theoretical model and magneto-hydrodynamic (MHD) codes, both of which primarily develop for the modeling of cylindrical wire array Z pinches.