论文标题
太阳电流板的热增强撕裂：用浆液捕获的冷凝物爆炸性重新连接
Thermally enhanced tearing in solar current sheets: explosive reconnection with plasmoid-trapped condensations
论文作者
论文摘要
在相关的电流板中，撕裂的不稳定性可能会触发爆炸性重新连接和浆液形成。我们探索热模式和撕裂模式如何通过爆炸性重新连接过程在太阳能电晕中的电流片段中相互加强，其特征在于形成的等离子体相互作用并捕获凝结等离子。我们使用2D电流层的电阻磁水动力学（MHD）模拟，结合了使用\ texttt {MPI-AMRVAC}的光学薄辐射能损失和背景加热的非绝热效应。我们的参数调查探讨了不同的电阻率和等离子体 - $β$，以量化线性和非线性方案中的不稳定性增长率。我们注意到，对于$ 10^{ - 4} - 5 \ times 10^{ - 3} $之内的无量纲电阻率值，我们得到了爆炸性的行为，而热不稳定性和撕裂行为相互加强。这显然低于纯电阻爆炸性浆液形成的通常关键lundquist数量范围。非线性生长速率遵循弱的电阻率依赖性。由于热和撕裂的不稳定性，当前板的碎片和在进化的非线性相中的浆液形成。在Lundquist号码（$ s_l $）范围$ 4.6 \ times 10^3-2.34 \ times 10^5 $的范围内注意到浆液的形成。我们在不同的物理条件下量化了浆液数的时间变化和浆液的密度填充因子。我们还发现，最大浆液数刻度为$ s_l^{0.223} $。在非线性合并的浆液链中，局部冷凝水聚集，实现与冠状雨或突出相似的密度和温度对比。
In flare-relevant current sheets, tearing instability may trigger explosive reconnection and plasmoid formation. We explore how the thermal and tearing modes reinforce each other in the fragmentation of a current sheet in the solar corona through an explosive reconnection process, characterized by the formation of plasmoids which interact and trap condensing plasma. We use a resistive magnetohydrodynamic (MHD) simulation of a 2D current layer, incorporating the non-adiabatic effects of optically thin radiative energy loss and background heating using \texttt{MPI-AMRVAC}. Our parametric survey explores different resistivities and plasma-$β$ to quantify the instability growth rate in the linear and nonlinear regimes. We notice that for dimensionless resistivity values within $10^{-4} - 5 \times 10^{-3}$, we get explosive behavior where thermal instability and tearing behavior reinforce each other. This is clearly below the usual critical Lundquist number range of pure resistive explosive plasmoid formation. The non-linear growth rates follow weak power-law dependency with resistivity. The fragmentation of the current sheet and the formation of the plasmoids in the nonlinear phase of the evolution due to the thermal and tearing instabilities are obtained. The formation of plasmoids is noticed for the Lundquist number ($S_L$) range $4.6 \times 10^3 - 2.34 \times 10^5$. We quantify the temporal variation of the plasmoid numbers and the density filling factor of the plasmoids for different physical conditions. We also find that the maximum plasmoid numbers scale as $S_L^{0.223}$. Within the nonlinearly coalescing plasmoid chains, localized cool condensations gather, realizing density and temperature contrasts similar to coronal rain or prominences.
