Measurement of magnetic field distribution produced by high-current pulse using Zeeman splitting of Na emission distributed by laser ablation.
Measurement of magnetic field distribution produced by high-current pulse using Zeeman splitting of Na emission distributed by laser ablation.
复制标题
DOI：
10.1063/5.0048319
复制
发表时间：
2021-09
期刊：
影响因子：
--
通讯作者：
Zhi-Yu Jiang;Jian Wu;Dao-zhong Zhang;Ziwei Chen;Zhenyu Wang;H. Shi;Xingwen Li;A. Qiu
中科院分区：
文献类型：
--
作者：
Zhi-Yu Jiang;Jian Wu;Dao-zhong Zhang;Ziwei Chen;Zhenyu Wang;H. Shi;Xingwen Li;A. Qiu
在z -夹紧实验中测量磁场分布仍然是一个持续的挑战。我们提出了一种测量铜棒周围磁场径向分布的方法，使用塞曼分裂钠（Na）发射线，在负载表面上通过激光烧蚀NaCl晶体形成Na层。负载由直径为2mm的铜棒组成，其表面预先覆盖有NaCl晶体。将能量为1j、波长为532nm的8ns脉冲激光聚焦在晶体上。钠等离子体产生并从铜棒表面膨胀到真空中。在负载上施加峰值为375 kA的脉冲电流后，Na 3s-3p双极态呈现出明显的塞曼分裂模式。为了消除不同观测角度和多普勒频移的影响，用谱仪和强化电荷耦合器件从端对端记录了钠等离子体的自发光。我们通过将测量光谱与Voigt剖面的计算结果拟合来确定磁场。径向位置的测量范围为5 ~ 7mm，对应的磁场为5 ~ 15t，曲线拟合的平均误差小于12%。
Measurement of the magnetic field distribution in Z-pinch experiments remains an ongoing challenge. We present a method of measuring the radial distribution of the magnetic field around a copper rod using Zeeman splitting of sodium (Na) emission lines, in which an Na layer is formed by the laser ablation of NaCl crystals on a load surface. The load consists of a copper rod of 2 mm diameter and is pre-covered on its surface by the NaCl crystals. An 8 ns pulsed laser with an energy of 1 J and wavelength of 532 nm is focused on the crystals. The Na plasma is produced and expands from the surface of the copper rod into a vacuum. After applying a pulsed current with a peak value of 375 kA to the load, the Na 3s-3p doublet displays significant Zeeman splitting patterns. The self-luminosity of the Na plasma is recorded by a spectrometer coupled with an intensified charge-coupled device camera from an end-on view to eliminate the effects of different observing angles and Doppler shifts. We determine the magnetic field by fitting the measured spectra with the calculated results of the Voigt profile. The measurable range of radial position is 5-7 mm, and the corresponding magnetic field is 5-15 T. The averaged error of curve fitting is less than 12%.