论文标题

与仅电子重新连接相关的湍流波动的统计特性

Statistical Properties of Turbulent Fluctuations Associated with Electron-only Magnetic Reconnection

论文作者

Arrò, Giuseppe, Califano, Francesco, Lapenta, Giovanni

论文摘要

上下文:地球湍流磁盘中的最新卫星测量结果证明了一种不寻常的重新连接机制,该机制仅由电子驱动。这个新观察到的过程称为仅电子重新连接,其与等离子体湍流的相互作用是一个很大的争论。 目的:通过使用2D-3V混合vlasov-Maxwell自由腐烂的血浆湍流模拟,我们研究了仅电子重新连接在血浆湍流发展中的作用。特别是,我们在与标准离子耦合重新连接相关的湍流方面寻找可能的差异。 方法:我们分析了湍流磁场和离子流体速度波动的结构函数,以表征湍流能量级联的结构和间歇性特性。 结果:我们发现,与仅电子重新连接相关的湍流波动的统计特性与与标准离子耦合重新连接相关的湍流波动的统计特性,并且在湍流统计数据中没有发现与仅电子重新连接相关的特殊签名。该结果表明,无碰撞磁化等离子体中的湍流能量级联反应不取决于与磁重新连接相关的特定机制。还讨论了耗散范围的特性,我们声称只有电子在亚离子尺度下磁场能的耗散。

Context: Recent satellite measurements in the turbulent magnetosheath of Earth have given evidence of an unusual reconnection mechanism that is driven exclusively by electrons. This newly observed process was called electron-only reconnection, and its inter-play with plasma turbulence is a matter of great debate. Aims: By using 2D-3V hybrid Vlasov-Maxwell simulations of freely decaying plasma turbulence, we study the role of electron-only reconnection in the development of plasma turbulence. In particular, we search for possible differences with respect to the turbulence associated with standard ion-coupled reconnection. Methods: We analyzed the structure functions of the turbulent magnetic field and ion fluid velocity fluctuations to characterize the structure and the intermittency properties of the turbulent energy cascade. Results: We find that the statistical properties of turbulent fluctuations associated with electron-only reconnection are consistent with those of turbulent fluctuations associated with standard ion-coupled reconnection, and no peculiar signature related to electron-only reconnection is found in the turbulence statistics. This result suggests that the turbulent energy cascade in a collisionless magnetized plasma does not depend on the specific mechanism associated with magnetic reconnection. The properties of the dissipation range are discussed as well, and we claim that only electrons contribute to the dissipation of magnetic field energy at sub-ion scales.

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