Magnetic Fields in Astrophysical Plasmas: Laboratory Studies of Amplification and Reconnection

by Dr Wei Sun(孙伟) (China Institute of Atomic Energy)

Friday 20 Nov 2026, 14:00 → 15:00 Asia/Shanghai

Tsung-Dao Lee Institute/N6F-N600 - Lecture Room (Tsung-Dao Lee Institute)

Host: Yipeng Wu
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Abstract:
Magnetic fields are ubiquitous in astrophysical plasmas, yet how they are amplified to dynamically important strengths and how they dissipate remain poorly understood. High-power lasers now make it possible to reproduce these processes under controlled and repeatable conditions and to test them against quantitative scaling laws. This report presents laboratory-astrophysics research on the amplification and reconnection of magnetic fields, combining experiments on the Shenguang-II laser facility with radiation-magnetohydrodynamic simulations. We show how laser-driven shocks and interfacial instabilities amplify seed fields by about two orders of magnitude during the evolution of a supernova remnant, first through shock compression and the Rayleigh–Taylor (RT) instability and then through a small-scale turbulent dynamo, and how scaling simulations extend these results to interacting remnant pairs. We further demonstrate that the RT instability, which in the solar corona arises from local density inhomogeneities such as those in coronal rain, can self-organize the thin current sheets required for fast magnetic reconnection, producing fields of alternating polarity with strengths of about 15 T, a reconnection rate of ≈0.08, and a twofold increase in electron temperature relative to shock-only heating, thereby providing a laboratory benchmark for nanoflare heating of the solar corona. We close by discussing how these field-generation and dissipation processes shape astrophysical jets and molecular-cloud collisions, and by outlining how laboratory measurements can provide quantitative constraints for observation and theory.

Biography:
Wei Sun is an Associate Researcher and master’s supervisor at the China Institute of Atomic Energy (CIAE), Beijing. He received his Ph.D. from Beijing Normal University in 2021 and joined CIAE in the same year. His research focuses on laboratory astrophysics. He has led six research projects, including the National Natural Science Foundation of China Young Scientists Fund, the CIAE Innovation Fund, and the CIAE President’s Fund, and has published more than 30 papers in journals such as Physical Review Letters, New Journal of Physics, Plasma Sources Science and Technology, and Physics of Plasmas.