Amazing stuff!
"Space weather events known as whistler mode chorus emissions have been observed in the laboratory for the first time. These emissions occur naturally within regions of space dominated by planetary magnetic fields – magnetospheres – and they are related to the aurorae that light up our northern and southern skies every winter. However, their exact origins are poorly understood, and until now, studying them has involved either spacecraft observations or numerical simulations. By recreating the conditions that produce these emissions, researchers at Japan’s National Institute for Fusion Science and the University of Tokyo hope to better understand them and how they affect orbiting satellites as well as ground-based power and communication networks. ..."
From the abstract:
"Wave particle interaction plays an important role in geospace and space weather phenomena. Whistler mode chorus emissions, characterized by non-linear growth and frequency chirping, are common in planetary magnetospheres. They are regarded as the origin of relativistic acceleration of particles in the radiation belts and pulsating aurora. Intensive theoretical investigations and spacecraft observations have revealed several important features of chorus emissions. However, there is a need to conduct high-resolution and reproducible controlled laboratory experiments to deepen the understanding of space weather. Here, we present the spontaneous excitation of chirping whistler waves in hot-electron high-β plasma (β is the ratio of the plasma pressure to the magnetic pressure) in an “artificial magnetosphere”, a levitated dipole experiment. These experiments suggest that the generation and nonlinear growth of coherent chorus emissions are ubiquitous in dipole magnetic configuration. We anticipate that these experiments will accelerate the laboratory investigation of space weather phenomena."
Fig. 1: Experimental setup and plasma formation in RT-1.
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