Engineering-Physics Space Plasma Seminar- Dr. Weijie Sun, University of Michigan
Title: "Energetic electrons associated with flux ropes in Earth’s plasma sheet"
Abstract: Magnetic reconnection is a universal process that is important both in laboratory and space plasmas. Magnetic reconnection can cause a macroscopic change in magnetic topology, and as a result, the separated plasma regions can be magnetically connected. Magnetic reconnection is also known as an effective way that converts magnetic energy into particles' kinetic and thermal energies. Theoretical physicists have been showing that magnetic reconnection plays an important role in energizing particles in astrophysics and space plasma physics. Their calculations and simulations show that flux ropes (or magnetic islands), which are important magnetic structures generated by magnetic reconnection, often appearing as a chain due to tearing instability can promote the acceleration of particles.
NASA’s magnetospheric multiscale (MMS) mission consists of four identical spacecraft, which provide high-temporal (30 ms for low energy electrons) and spatial resolution (~ 10 km, local de), multi-points of field and particle measurements. In this presentation, I will present our latest studies on the properties and acceleration mechanisms of electrons associated with flux rope chains and reconnection X-lines by using the measurements from the MMS. The fundamental acceleration mechanisms, including the Betatron process, the Fermi process, and the parallel electric field, are directly assessed and are shown to be important in different regions. I will also discuss the highest energy of adiabatic electrons, examine the power-law spectra of electrons, and discuss the roles of adiabatic and non-adiabatic energization processes. The results of our investigations should advance our understanding of the role of magnetic flux ropes in charged particle acceleration of all cosmic plasmas.
Hosted By Xiaocan Li and Yi-Hsin Liu
Join Zoom Meetinghttps://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdartmouth.zoom.us%2Fj%2F92751420885%3Fpwd%3DQnIwN0RiSGkzMUtjQVZxRlZLMkcwQT09&data=05%7C01%7CTressena.A.Manning%40dartmouth.edu%7C5eefdec2ef9949c4f6b708db0e90c24a%7C995b093648d640e5a31ebf689ec9446f%7C0%7C0%7C638119787116603756%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=iD8rdTTkDtdp5cC5Iw4FE5Zb3O%2BL859hFgYQLRo%2Bt%2BI%3D&reserved=0Meeting ID: 927 5142 0885Passcode: Plasma
