Physics Department Colloquia
Events on Friday, April 29th, 2016
- When Magnetic Field Lines Break
- Time: 3:30 pm
- Place: 2241 Chamberlin Hall (Coffee & Cookies at 3:15pm)
- Speaker: Paul Cassak, West Virginia University
- Abstract: Freshman physics tells us that magnetic field lines are not allowed to have free ends. However, counterintuitively, magnetic field lines are allowed to break! When this process occurs in high temperature plasmas, it is called magnetic reconnection. Rather than simply being a curiosity, it turns out to be a crucial phenomenon as it facilitates the conversion of magnetic energy into kinetic energy and heat of the surrounding plasmas. It is the mechanism behind the energy release in solar flares and coronal mass ejections, geomagnetic storms producing aurora, disruptive events in magnetically confined fusion plasmas, and in many astrophysical contexts. Consequently, understanding reconnection is a key aspect of both mitigating the harmful effects of space weather and the harnessing of essentially renewable energy through fusion. Studying reconnection was the motivation for the recently-launched NASA Magnetospheric Multiscale (MMS) mission. In this talk, results using theoretical techniques and a number of different supercomputer numerical simulations will be shown. Applications to the boundary of the region of influence of Earth’s magnetic field (the magnetosphere) and fusion will be discussed.
- Host: Jan Egedal