Non-local Ohm's law during collisions of magnetic flux ropes
Non-local Ohm's law during collisions of magnetic flux ropes
复制标题
磁通绳碰撞过程中的非局部欧姆定律
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
R. Sydora
中科院分区：
文献类型：
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作者：
W. Gekelman;T. DeHaas;P. Pribyl;S. Vincena;B. V. Compernolle;R. Sydora
在经过仔细诊断的实验室实验中产生了两条扭结不稳定磁通绳。使用探针，时变磁场，等离子体电位，等离子体流量，温度和密度测量超过42 000个空间位置。这些被用来推导欧姆定律中的所有项，以计算等离子体电阻率。该方法计算的电阻率在一定的空间区域和时间内为负值。欧姆定律被证明是非局部的。相反，在磁通绳扭结频率下的久保电阻率是使用波动耗散定理计算的。平行于磁场的电阻率是经典值的40倍，并在磁场线重联发生的地方以及在大磁通绳电流的区域达到峰值。
Two kink unstable magnetic flux ropes are produced in a carefully diagnosed laboratory experiment. Using probes, the time varying magnetic field, plasma potential, plasma flow, temperature, and density were measured at over 42 000 spatial locations. These were used to derive all the terms in Ohm's law to calculate the plasma resistivity. The resistivity calculated by this method was negative in some spatial regions and times. Ohm's law was shown to be non-local. Instead, the Kubo resistivity at the flux rope kink frequency was calculated using the fluctuation dissipation theorem. The resistivity parallel to the magnetic field was as large as 40 times the classical value and peaked where magnetic field line reconnection occurred as well as in the regions of large flux rope current.