The effect of current prepulse on wire array Z-pinch implosions
The effect of current prepulse on wire array Z-pinch implosions
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DOI：
10.1063/1.1417512
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发表时间：
2002
影响因子：
2.2
通讯作者：
F. Beg;S. Lebedev;S. Bland;J. Chittenden;A. Dangor;M. Haines
中科院分区：
文献类型：
--
作者：
F. Beg;S. Lebedev;S. Bland;J. Chittenden;A. Dangor;M. Haines
研究了预脉冲电流对线阵Z箍缩行为的影响。这些实验是在喜鹊发电机(峰值电流为1 mA，240 ns)上进行的[I.Mitchell，J.M.Bayley，J.P.Chittenden等，Rev.Sci。Instrum。67,1533(1996)]。采用∼500 ns长的线性斜坡电流作为预脉冲。该阵列由32根15-μm的铝线组成，长23 mm，排列成直径16 mm的圆圈。在预脉冲为1kA/线的情况下，在主电流开始之前，在阵列轴线上形成了低密度前体等离子体柱(Ne∼2×1017 cm−3)。随后，软X射线发射显示前体等离子体中m=1螺旋不稳定性的增长，这表明存在电流。在没有预脉冲电流的情况下，前驱等离子体在轴上是均匀的，不表现出任何不稳定性。在轴向停滞时，有预脉冲电流的X射线脉冲比没有预脉冲电流时的X射线脉冲小至少30倍。
The effect of a prepulse current on the behavior of wire array Z pinches is investigated. The experiments were performed on the MAGPIE generator (1 MA peak current at 240 ns) [I. Mitchell, J. M. Bayley, J. P. Chittenden et al., Rev. Sci. Instrum. 67, 1533 (1996)]. A linear ramp current, ∼500-ns long, was used as a prepulse. The array consisted of 32 15-μm aluminum wires, 23-mm long arranged in a 16-mm diameter circle. With a prepulse of 1 kA/wire, a low density precursor plasma column (ne∼2×1017 cm−3) is formed on the array axis before the start of the main current. Later, the soft x-ray emission shows the growth of an m=1 helical instability in the precursor plasma, which indicates the presence of a current. Without a prepulse current, the precursor plasma on axis is uniform and does not show any instability. The x-ray pulse at stagnation on axis is at least 30 times smaller with a prepulse current than without.