Events at Physics |
Events on Monday, November 2nd, 2020
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Magnetic Reconnection and the Acceleration of Electrons in Macroscale Systems
- Time: 12:00 pm
- Place: ZOOM Meeting
- Speaker: Dr. Marc Swisdak, University of Maryland
- Abstract: Magnetic reconnection is a ubiquitous process that transfers energy from the magnetic field to the surrounding plasma. It is believed to trigger such energetic events as tokamak sawtooth crashes, magnetospheric substorms, and solar and astrophysical flares. I will first outline the current understanding of this phenomenon and then focus particularly on the production of non-thermal (energetic) particles. In the case of solar flares, the spectra of energetic electrons take the form of power laws that extend decades in energy and can account for half of the released magnetic energy. New simulations, based on a recently developed model that marries MHD and kinetic physics, will be discussed that have produced the first self-consistent power-law distributions in a macroscale system. The drive mechanism is Fermi reflection in growing and merging magnetic flux ropes. A strong guide field is found to suppress the production of nonthermal electrons by increasing the radius of curvature of reconnected field lines and therefore weakening the Fermi drive mechanism. The results are benchmarked with the hard x-ray, radio and extreme ultra-violet (EUV) observations of the X8.2-class solar flare on September 10, 2017.
Connection information:
Join Zoom Meeting
Meeting ID: 991 5610 7574
Passcode: 883688 - Host: Paul Terry