“荧光-1”是一套分时放电的大电流脉冲功率实验装置,主要用于反场构形预加热磁化等离子体靶(FRC)形成的物理过程、高温高密度磁化等离子体约束特性等研究,未来可作为磁化靶聚变研究的等离子体注入器。主要介绍该实验装置的构成及其调试实验结果,并简要描述在该装置上开展的FRC等离子体靶初步物理实验进展。调试实验结果表明,“荧光-1”实验装置初始磁场、磁镜、气体电离、θ箍缩分系统的放电电流/磁场或感应电场可分别达到110 kA/0.3 T,10 kA/1.2 T,400 kA/0.25 kV/cm,1.7 MA/3.4 T。初步物理实验获得的FRC等离子体靶参数为: 靶分界面半径约4 cm、等离子体密度3.5×1016 cm-3、等离子体温度约200 eV、靶寿命约3 μs,同时清晰地观察到了FRC靶形成物理过程。分幅相机获取图像与二维磁流体程序计算图像基本吻合,验证了该装置的物理设计思路,也展示了该装置具备的物理实验能力。

“Yingguang-1” is a multi-bank program-discharged pulsed power device for investigating the formation, confinement and instability of the high temperature and high density field reversed configuration (FRC) plasma injector in magnetized target fusion (MTF), which has been constructed at the Institute of Fluid Physics (IFP) in 2014. In this paper we will present the composition and the parameters of the “Yingguang-1” device, and briefly describe the progress on the experiments of the FRC formation. In construction of the “Yingguang-1” device, the rail gap switch with the peak current of 400 kA and the corresponding trigger system with the voltage greater than 200 kV and rise time less than 20 ns were firstly developed. Utilizing the mixture of 25% sulfur hexafluoride (SF6) and 75% nitrogen (N2) as the insulation gas, the switch could operate from 50 kV to 150 kV and the maximum offset of the start-up time would be less than 50 ns during repetitive test. By the high speed frame camera more than 5 discharged channels were observed in the switch. Experimental results of the pulsed power system show that the peak current/magnetic fields were 110 kA/0.3 T, 10 kA/1.2 T and 1.7 MA/3.4 T in the bias, mirror and θ-pinch circuit with the quarter cycle of 80 μs, 700 μs and 3.8 μs when the charging voltage were set to 7 kV, 7 kV and ±60 kV respectively. After the construction of “Yingguang-1” device the preliminary experiments of the FRC target formation was conducted. With the H2 gas of 8.5 Pa, the plasma target of density 3.5×1016cm-3, separatrix radius 4 cm, length 17 cm, average total temperature 200 eV and life time 3 μs approximately equals to the half pulse width of the reversed field were obtained through the θ-pinch method when the bias, mirror, ionization and θ-pinch bank were charged to 5 kV, 5 kV, 55 kV and ±45 kV respectively. The images from the end-on frame camera demonstrate the formation of FRC and agree with the results from the two dimension magneto hydrodynamics code (2D-MHD).