MIT and Columbia University's School of Engineering are on a collaborative mission to explore “space weather” by using experiments here on Earth.
Scientists from both institutions have received a $1.2 million, three-year grant from the National Science Foundation (NSF) and the U.S. Department of Energy Office of Fusion Energy Sciences to jointly develop and test models of space weather. Local weather forecasts do not typically include information about what is happening beyond the Earth’s ionosphere. But being able to predict “space weather” could be of crucial importance. Understanding geomagnetic storms that are caused by massive plumes of plasma ejected from the Sun could be used to plan satellite operations, predict radio outages and protect the electrical transmission grid.
“We’re really excited about this funding,” says MIT visiting scientist Mike Mauel, who is a professor of applied physics and mathematics at Columbia Engineering and Applied Science and one of the lead researchers on the project. “With this grant, we’ll be able to test our understanding of how space plasma swirls and mixes by making careful measurements of hot plasma dynamics in the lab.”
The joint research project will explore how high-temperature ionized gas (plasma) responds when trapped by strong magnets that mimic the Earth’s magnetosphere, the gigantic bubble of plasma that surrounds the Earth, protecting it from high-speed solar wind and resulting space weather. Jay Kesner, a research scientist at MIT’s Plasma Science and Fusion Center, explains that “although our direct observations of the solar surface and satellite measurements of the solar wind can give us warnings of possible subsequent geomagnetic activity, we need more accurate and reliable models of how solar fluxes effect the earth's space environment.”
During the past decade, two university research teams — including Kesner, Mauel, Columbia research scientist Darren Garnier and more than a dozen students — have built and operated two unique "laboratory magnetospheres": the Collisionless Terrella Experiment (CTX) located at Columbia University and the Levitated Dipole Experiment (LDX) located at MIT. The strong magnets in these experiments can confine plasma at very high pressure and with intense energetic electron belts similar to the Earth's radiation belts. Equipped with plasma diagnostics capable of multi-scale measurements, students perform controlled experiments that enable laboratory study of important phenomena in space weather, such as fast particle excitation and rapid electromagnetic events associated with magnetic storms.
The CTX experiment consists of an easy-to-operate water-cooled dipole magnet suspended in a 1.7 meter diameter vessel. The Levitated Dipole Experiment (LDX) at MIT is a larger facility, containing a half-ton, high-current superconducting ring, which is "levitated" for hours inside a 5-meter diameter vacuum vessel. When the current-ring is levitated, a large laboratory magnetosphere is created with very high plasma pressure, allowing researchers to observe large, slow-moving vortex tubes that align with the magnetic field.
As explained by Mauel, “The simplicity of the dipole field gives students hands-on experiences with space physics, and allows them to test new insights of turbulent mixing and space weather dynamics.”