Laboratory evidence of dynamo amplification of magnetic fields in a turbulent plasma.
Laboratory evidence of dynamo amplification of magnetic fields in a turbulent plasma.
复制标题
DOI：
10.1038/s41467-018-02953-2
复制
发表时间：
2018-02-09
影响因子：
16.6
通讯作者：
Gregori G
中科院分区：
文献类型：
--
作者：
Tzeferacos P;Rigby A;Bott AFA;Bell AR;Bingham R;Casner A;Cattaneo F;Churazov EM;Emig J;Fiuza F;Forest CB;Foster J;Graziani C;Katz J;Koenig M;Li CK;Meinecke J;Petrasso R;Park HS;Remington BA;Ross JS;Ryu D;Ryutov D;White TG;Reville B;Miniati F;Schekochihin AA;Lamb DQ;Froula DH;Gregori G
磁场在宇宙中无处不在。这些场的能量密度通常与它们所嵌入的等离子体的流体运动的能量密度相当，使得磁场在发光物质的动力学中发挥重要作用。这些强磁场起源的标准理论模型是通过湍流发电机将微小的种子场放大到与当前观测一致的水平。然而，湍流发电机机制的实验演示仍然难以捉摸，因为它需要在地面实验室中极难重现的等离子体条件。在这里，我们证明，使用激光产生的碰撞等离子体流，湍流确实能够迅速放大种子场近均分的湍流流体运动。这些结果支持的概念，湍流发电机是一个可行的机制，负责所观察到的现今的磁化。由于相关参数的高阈值，如磁雷诺数，探索实验室等离子体中的天体物理湍流效应是具有挑战性的。在这里，作者证明了在大磁雷诺数的激光产生的磁化等离子体的湍流发电机效应。
Magnetic fields are ubiquitous in the Universe. The energy density of these fields is typically comparable to the energy density of the fluid motions of the plasma in which they are embedded, making magnetic fields essential players in the dynamics of the luminous matter. The standard theoretical model for the origin of these strong magnetic fields is through the amplification of tiny seed fields via turbulent dynamo to the level consistent with current observations. However, experimental demonstration of the turbulent dynamo mechanism has remained elusive, since it requires plasma conditions that are extremely hard to re-create in terrestrial laboratories. Here we demonstrate, using laser-produced colliding plasma flows, that turbulence is indeed capable of rapidly amplifying seed fields to near equipartition with the turbulent fluid motions. These results support the notion that turbulent dynamo is a viable mechanism responsible for the observed present-day magnetization. Exploring astrophysical turbulent effects in laboratory plasma is challenging due to high threshold values of relevant parameters, such as the magnetic Reynolds number. Here the authors demonstrate the turbulent dynamo effect at large magnetic Reynolds numbers in laser-generated magnetized plasma.
登录
查看更多内容
影响因子：
8.6
作者：
Gailitis, A;Lielausis, O;Will, G
通讯作者：
Will, G
影响因子：
8.7
作者：
Fryxell, B;Olson, K;Tufo, H
通讯作者：
Tufo, H
影响因子：
8.6
作者：
Gailitis, A;Lielausis, O;Will, G
通讯作者：
Will, G
影响因子：
2.4
作者：
Haugen, NEL;Brandenburg, A;Dobler, W
通讯作者：
Dobler, W
影响因子：
--
作者：
BIERMANN, L;SCHLUTER, A
通讯作者：
SCHLUTER, A