Study on Magnetic Reconection Caused by Electromagnetic Energy

磁场重联是一种普遍存在于太阳耀斑、磁层和托卡马克等离子体中的动力学现象，它与电磁场和等离子体有关。迄今为止，人们对这一现象的物理机制进行了大量的实验、观测和理论研究，但仍有许多问题没有得到解决（"电流跳跃"）当在LATE装置中的弱稳定垂直磁场下产生电子回旋共振环形等离子体时，并观察到电流从开放场位形自发跳变到闭合场位形期间磁场拓扑发生变化，即，结果表明，在垂直场强为7~85G的宽场强范围内，注入微波功率为1~130kW，微波频率为2.45和5GHz时，电流发生跳跃。使用磁性测量，h ...更多信息 利用CdTe半导体探测器、软X射线CT和快速CCD照相机进行X射线脉冲高度分析，发现模式转换电子伯恩斯坦波加热和电子的各向异性约束特性使环向电流产生并迅速增加，自生极向场引起磁力线重联。在LATE上壁安装可移动的静电离子探测器/电探针，用于探测电流跃变过程中沿着开磁力线的等离子体流动。通过改变探测器的位置，得到了离子饱和电流的时间演化和空间分布。观察到在电流跳跃过程中，离子饱和电流局部增大了几倍，这可能是重联过程中等离子体流沿场线沿着加速所致。少

Magnetic reconnection is observed in solar flares, magnetosphere and tokamak plasmas, and is widely known as a dynamical and general phenomenon involved with electromagnetic field and plasmas. So far, many experiments and observations as well as theoretical investigations are devoted to explain the physical mechanism but many questions still remain unresolved.We discovered at the first time that toroidal plasma current increased rapidly ("current jump") when an electron cyclotron resonance torus plasma was produced under a weak steady vertical magnetic field in the LATE device, and observed that the magnetic filed topology was changed during the current jump from open field configuration to closed one spontaneously, i.e., under the constant external conditions.It was shown that the current jump occurred under the wide vertical field strength from 7 to 85 G, changing the injected microwave power from 1 to 130 kW and microwave frequencies as 2.45 and 5 GHz. Using magnetic measurements, h … More ard X-ray pulse height analysis with CdTe semiconductor detectors, soft X-ray CT and fast CCD camera, it was found that the toroidal current was generated and increased rapidly by mode-converted electron Bernstein wave heating and anisotropic confinement property of electrons, and the self-produced poloidal field caused reconnection of magnetic field lines. The characteristics of toroidal MHD equilibrium also changes from the pressure-ballooning-force-dominant to the current-loop-force-dominant.A movable electrostatic ion detector/electrical probe was attached to the upper wall of LATE to detect the plasma flow along the open field lines during the current jump. Time evolution and spatial distribution of ion saturation current were obtained by changing the position of the detector shot by shot. It was observed that the ion saturation current increased severalfold during the current jump locally, which may be caused by the plasma flow accelerated along the field lines during the reconnection. Less