Experimental study of magnetic bubble expansion as a model for extragalactic radio lobes

0613577 Lynnesville项目将进行实验室实验和协调的数值模拟，以帮助解决与河外喷流携带的磁能和螺旋度如何与星系间介质达到准平衡有关的突出等离子体物理问题，形成巨大的“射电瓣”，被认为是巨大的松弛等离子体。 这些实验将研究磁化等离子体气泡膨胀并与低压背景等离子体达到平衡时的弛豫。 主要的科学目标是表征气泡弛豫的基本非线性等离子体物理，包括磁通量转换，离子和电子加热，角动量演化/运输。 这些非线性等离子体物理问题目前还不能仅仅通过数值计算或天文观测来解决。 实验结果将提供深入了解的气泡膨胀/松弛过程和所需的数据验证数值计算正在进行的这一领域。 将调整实验参数，使重要的无量纲参数有关的磁通量，电流，螺旋度注入率（和持续时间），和总注入螺旋度是相关的天体物理背景。

0613577LynnThis project will conduct laboratory experiments and coordinated numerical modeling to help address outstanding plasma physics issues related to how magnetic energy and helicity carried by extra-galactic jets reach quasi-equilibrium with the intergalactic medium, forming gigantic 'radio lobes' which are thought to be gigantic relaxed plasmas. The experiments will study the relaxation of a magnetized plasma bubble as it expands into and reaches equilibrium with a lower pressure background plasma. The primary scientific objectives are to characterize the underlying nonlinear plasma physics of the bubble relaxation, including magnetic flux conversion, ion and electron heating, and angular momentum evolution/transport. These nonlinear plasma physics issues cannot at present be resolved from numerical computation or astronomical observations alone. The experimental results will provide insights into the bubble expansion/relaxation process and the needed data for validating numerical computations being carried out in this field. Experimental parameters will be adjusted so that important dimensionless parameters relating to magnetic flux, electric current, helicity injection rate (and duration), and total injected helicity are relevant for the astrophysical context.