SHINE: Improving Understanding of Solar Corona Dynamics Using Laboratory Simulations of Coronal Loops

首席调查员(PI)将使用具有脉冲功率技术的等离子室对太阳日冕现象进行实验室模拟。等离子体实验的时间刻度将被设置为与电阻扩散时间相比要短，以“冻结”磁通量，但与阿尔芬时间相比又足够长，以允许通过一系列不同的状态进行演化。这些等离子体将经历复杂的形态变化，这取决于施加的边界条件，如法向磁场、电流密度和等离子体质量通量。通过控制这些边界条件，将产生各种各样的实验等离子体构型，例如，模拟单个日冕环、两个螺旋度相同或相反的相邻环，或八个环的“蜘蛛腿”构型。不同的实验配置和诊断将被用来研究几种不同的与太阳相关的现象，包括磁流体(MHD)驱动的喷流，最近发现的非MHD“动能”喷流，以及与相邻等离子体填充的磁通量管合并相关的X射线发射。每两分钟将产生一次可复制的等离子体配置。将使用先进的诊断技术来确定等离子体行为，包括以高达2亿帧/秒的成帧速率进行高速数字成像、用于测量时间和空间分辨率密度的成像光谱学、用于测量线平均密度的激光干涉测量法、用于测量内部磁场的多元素磁性探头，以及用于为X射线源成像的针孔X射线相机。实验测量将与理论模型的预测进行比较，然后用于改进、修改或挑战这些模型。PI将让一名研究生参与这些实验，并将结果用于本科生的培训。PI有致力于增加从事等离子体物理工作的女性博士科学家数量的记录。他还通过高度可视化的实验维持了一个成功的公共宣传计划，这些实验在主要科学期刊的封面和教科书上以五颜六色的图形出现。

The Principal Investigator (PI) will perform laboratory simulations of solar coronal phenomena using a plasma chamber with pulsed power technology. The plasma experimental regime will be set to have a time scale that is short compared to the resistive diffusion time in order to "freeze in" magnetic flux, yet that is sufficiently long compared to the Alfven time to allow evolution through a sequence of distinct states. These plasmas will undergo complex morphological changes that depend on imposed boundary conditions, such as normal magnetic field, current density, and plasma mass flux. By controlling these boundary conditions, a wide variety of experimental plasma configurations will be produced simulating, for example, a single solar coronal loop, two adjacent loops of same or opposite helicity, or an eight loop "spider-leg" configuration. The various experimental configurations and diagnostics will be used to investigate several different solar-relevant phenomena, including magnetohydrodynamic (MHD)-driven jets, a recently-discovered non-MHD "kinetic" jet, and x-ray emission associated with merging of adjacent plasma-filled magnetic flux tubes.Reproducible plasma configurations will be created once every two minutes. Plasma behavior will be determined using advanced diagnostics, including high speed digital imaging at framing rates up to 200 million frames per second, imaging spectroscopy to measure time- and space-resolved density, laser interferometry to measure line-averaged density, multi-element magnetic probes to measure internal magnetic fields, and a pinhole x-ray camera to image x-ray sources. Experimental measurements will be compared to predictions of theoretical models and then used to improve, modify, or challenge these models. The PI will involve a graduate student in these experiments, as well as use the results for training undergraduates. The PI has a record of commitment to increasing the number of women PhD scientists working in plasma physics. He has also sustained a successful public outreach program through of the highly visual nature of his experiments, which have been featured in colorful graphics on the covers of major science journals and in textbooks.