Suttle L G, Hare J D, Lebedev S V, Swadling G F, Burdiak G C, Ciardi A, Chittenden J P, Loureiro N F, Niasse N, Suzuki-Vidal F, Wu J, Yang Q, Clayson T, Frank A, Robinson T S, Smith R A, Stuart N
Blackett Laboratory, Imperial College, London SW7 2BW, United Kingdom.
Sorbonne Universités, UPMC Universités Paris 6, UMR 8112, LERMA, Paris F-75005, France.
Phys Rev Lett. 2016 Jun 3;116(22):225001. doi: 10.1103/PhysRevLett.116.225001. Epub 2016 May 31.
We present experiments characterizing the detailed structure of a current layer, generated by the collision of two counterstreaming, supersonic and magnetized aluminum plasma flows. The antiparallel magnetic fields advected by the flows are found to be mutually annihilated inside the layer, giving rise to a bifurcated current structure-two narrow current sheets running along the outside surfaces of the layer. Measurements with Thomson scattering show a fast outflow of plasma along the layer and a high ion temperature (T_{i}∼Z[over ¯]T_{e}, with average ionization Z[over ¯]=7). Analysis of the spatially resolved plasma parameters indicates that the advection and subsequent annihilation of the inflowing magnetic flux determines the structure of the layer, while the ion heating could be due to the development of kinetic, current-driven instabilities.
我们展示了一些实验，这些实验表征了由两个反向流动、超音速且磁化的铝等离子体流碰撞所产生的电流层的详细结构。研究发现，由这些流携带的反平行磁场在电流层内部相互抵消，从而产生了一种分叉电流结构——两个沿着电流层外表面延伸的狭窄电流片。汤姆逊散射测量结果表明，等离子体沿着电流层快速流出，且离子温度较高（(T_{i}\sim\overline{Z}T_{e})，平均电离度(\overline{Z}=7)）。对空间分辨等离子体参数的分析表明，流入磁通量的平流及其随后的抵消决定了电流层的结构，而离子加热可能是由于动力学电流驱动不稳定性的发展所致。
