Magnetic reconnection takes place when electromagnetic field lines of opposite instructions merge, rejoin, and snap apart, releasing huge amounts of energy to heat plasmas and drive high-speed outflows. Credit: Yi-Hsin Liu/Dartmouth College
” The rate at which electromagnetic field lines reconnect is of extreme importance for procedures in area that can impact Earth,” said Yi-Hsin Liu, an assistant teacher of physics and astronomy at Dartmouth. “After decades of effort, we now have a complete theory to resolve this enduring problem.”
Magnetic reconnection exists throughout nature in plasmas, the 4th state of matter that fills the majority of the noticeable universe. Reconnection takes place when electromagnetic field lines of opposite directions are drawn to each other, break apart, rejoin, and then strongly snap away.
In the case of magnetic reconnection, the snapping of magnetic lines forces out allured plasma at high velocities. The energy is created and displaced to plasmas through a tension force like that which ejects objects from slingshots.
Around the region where reconnection occurs, the departure of the ion movement (blue streamlines in (a)) from the electron motion (red streamlines in (a)) generates the “Hall result,” which leads to the electro-magnetic energy transportation pattern highlighted by yellow streamlines in (b). This transport pattern restricts the energy conversion at the center, allowing fast reconnection. Credit: Yi-Hsin Liu/Dartmouth College
The Dartmouth research study focused on the reconnection rate issue, the key component of magnetic reconnection that explains the speed of the action in which magnetic lines assemble and pull apart.
Previous research study found that the Hall Effect– the interaction in between electrical currents and the magnetic fields that surround them– produces the conditions for quick magnetic reconnection. Up until now researchers were not able to discuss the details of how exactly the Hall result improves the reconnection rate.
The Dartmouth theoretical study shows that the Hall effect reduces the conversion of energy from the electromagnetic field to plasma particles. This restricts the quantity of pressure at the point where they combine, requiring the magnetic field lines to curve and pinch, resulting in open outflow geometry required to speed up the reconnection procedure.
Dartmouths Xiaocan Li, postdoctoral researcher (left); Yi-Hsin Liu, Assistant Professor of Physics and Astronomy (center); Shan-Chang Lin, PhD prospect (right). Credit: Robert Gill/Dartmouth College
” This theory addresses the essential puzzle of why and how the Hall impact makes reconnection so quickly,” said Liu, who serves as deputy lead of the theory and modeling team for NASAs Magnetospheric Multiscale Mission (MMS). “With this research, we likewise have actually discussed the explosive magnetic energy release process that is essential and common in natural plasmas.”
The new theory could even more the technical understanding of solar flares and coronal mass ejection events that trigger space weather and electrical disruptions on Earth. In addition to using the reconnection rate to approximate the time scales of solar flares, it can likewise be utilized to identify the strength of geomagnetic substorms, and the interaction between the solar wind and Earths magnetosphere.
Yi-Hsin Liu, Assistant Professor of Physics and Astronomy, Dartmouth College Credit: Robert Gill/Dartmouth College.
The research study team, funded by the National Science Foundation (NSF) and NASA, is working alongside NASAs Magnetospheric Multiscale Mission to analyze magnetic reconnection in nature. Information from 4 satellites flying in tight development around Earths magnetosphere as part of the NASA mission will be utilized to confirm the Dartmouth theoretical finding.
” This work demonstrates that fundamental theory insights enhanced by modeling abilities can advance clinical discovery,” said Vyacheslav Lukin, a program director for plasma physics at NSF. “The societal and technological implications of these results are intriguing as they can help anticipate impacts of area weather condition on the electrical grid, develop new energy sources, and check out unique space propulsion innovations.”
The new study can also notify reconnection studies in magnetically restricted fusion gadgets and astrophysical plasmas near neutron stars and black holes. Although there is no current applied use, some scientists have actually considered the possibility of using magnetic reconnection in spacecraft thrusters.
Referral: “First-principles theory of the rate of magnetic reconnection in solar and magnetospheric plasmas” by Yi-Hsin Liu, Paul Cassak, Xiaocan Li, Michael Hesse, Shan-Chang Lin and Kevin Genestreti, 28 April 2022, Communications Physics.DOI: 10.1038/ s42005-022-00854-x.
This work is moneyed by the NSFs PHY and AGS Divisions, NASAs Magnetospheric Multiscale (MMS) objective, and the U.S. Department of Energy.
Co-authors of the research study are Paul Cassak, West Virginia University; Xiaocan Li, Dartmouth; Michael Hesse, NASAs Ames Research Center; Shan-Chang Lin, Dartmouth; and Kevin Genestreti, Southwest Research Institute.
Solar flares and coronal mass ejections on the sun are triggered by “magnetic reconnection”– when magnetic field lines of opposite instructions merge, rejoin, and snap apart, producing surges that release huge amounts of energy. Credit: NASA Conceptual Image Laboratory
Researchers recognize the physics that makes it possible for quick magnetic surges in space.
When magnetic field lines of opposite directions combine, they create surges that can release significant quantities of energy. The combining of opposing field lines on the sun produces solar flares and coronal mass ejections, which are huge blasts of energy that can travel to Earth in less than a day.
While the basic mechanics of magnetic reconnection are well understood, scientists have struggled for over a half-century to explain the precise physics behind the quick energy release that takes place.
A brand-new Dartmouth research study published the other day (April 28, 2022) in the journal Communications Physics offers the first theoretical description of how a phenomenon referred to as the “Hall impact” identifies the performance of magnetic reconnection.
