利用PPG-1脉冲电流源(400 kA,100 ns),同时驱动X-pinch和双丝Z箍缩负载。用X-pinch作为X射线源,对双丝Z箍缩进行了轴向背光照相的初步实验。得到了双丝Z箍缩在r-θ平面上随时间演化的图像,观察到了丝阵Z箍缩所有早期过程,包括丝芯膨胀、冕层等离子体产生、等离子体向丝阵中心的运动、先驱等离子体形成。利用阶跃光楔滤片,对上述背光图像进行了等离子体质量面密度的标定,首次得到了在r-θ平面上双丝Z箍缩等离子体质量面密度的时空分布图像。
The axial backlighting of two-wire Z-pinch using an X-pinch as an X-ray source was conducted on PPG-1, a pulsed power generator with a current of 400 kA in amplitude and 100 ns in pulse width. Its time-resolved axial backlighting images are obtained. In the backlighting images all the physical processes similar to those occurring in the early stage of the wire-array Z-pinch are observed, including the expansion of the high-density wire core surrounded by low-density coronal plasmas, the motion of the coronal plasma toward the axis of the wire-array, and the formation of precursor plasma. The areal mass density of the plasma shown in the backlighting images is calibrated with step-wedge filters. And the time-resolved radial distributions of the areal mass density of the plasma from the two-wire Z-pinch are obtained.