Experiments on Alfven Waves

阿尔芬波在空间等离子体中普遍存在，许多航天器已经在各种条件下观测到了阿尔芬波的特征。大量的理论工作和计算机模拟直接或间接地涉及到它们，尽管在这一领域已经有了不成比例的少量的实验室实验。其原因是缺乏能够对这些波进行清洁和详细研究的实验室等离子体源。最近，加州大学洛杉矶分校建造了一台机器，它具有10米长、直径50厘米的等离子体柱。这台机器可以在中等密度、高度电离(99%)氦或氢等离子体下运行，轴向均匀磁场高达2.5公斤。我们提出了一系列实验来验证我们可以发射和检测Alfven波，然后使用最先进的数据收集和可视化系统对其进行诊断。

Alfven waves are ubiquitous in space plasmas and their signatures have been observed by many spacecraft under a variety of conditions. A large amount of theoretical work and computer simulations deal with them directly or indirectly although there have been a disproportionately small amount of laboratory experiments in this area. The reason for this is the lack of laboratory plasma sources in which clean, and detailed studies of these waves can be performed. Recently, a machine has been constructed at UCLA which features a 10m long, 50 cm diameter plasma column. The machine can be operated in a regime of moderate density, highly ionized (99%) He or H plasmas in a uniform axial field of up to 2.5 kG. We propose a series of experiments to verify that we can launch and detect Alfven waves, and then diagnose them with a sate-of-the-art data collection and visualization system.