Author ORCID Identifier
https://orcid.org/0000-0002-2843-8106
Date of Award
Summer 7-24-2025
Document Type
Thesis (Ph.D.)
Department or Program
Physics and Astronomy
First Advisor
Yi-Hsin Liu
Abstract
Magnetic reconnection is a physical process in plasmas that converts magnetic energy into plasma kinetic energy and thermal energy. It plays an important role in the generation of solar flares, interactions between the solar wind and Earth's magnetosphere, and magnetic confinement fusion devices. This thesis focuses on studying magnetic reconnection using computational methods, including two-dimensional (2D) magnetohydrodynamics (MHD) simulations to study Petschek-type reconnection, estimating the timescale from a thin current sheet to fully developed reconnection using 2D particle-in-cell (PIC) simulations, and magnetic reconnection X-line spreading in the current direction using three-dimensional (3D) PIC simulations.
This thesis contributes to the understanding of magnetic reconnection physics in space plasmas. In Chapter 2, we found that a resistivity gradient along the outflow direction can generate Petschek-type reconnection in MHD simulations, and the reconnection rate is of the order 0.1 even for a very large exponential resistivity applied. This finding has possible applications in solar spicules formation or plasma thrusters. In Chapter 3, we found that X-line spreading will be affected by drift-kink instability. This finding might be important for modeling energy transport into Earth's magnetosphere via reconnection in Earth's magnetotail. In Chapter 4, a simplified model of the evolution from a thin current sheet to steady-state magnetic reconnection has been derived and compared with 2D PIC simulations. This finding could be important for modeling magnetic reconnection in Earth's magnetotail.
Original Citation
Lin, Shan-Chang, Yi-Hsin Liu, and Xiaocan Li. "Fast magnetic reconnection induced by resistivity gradients in 2D magnetohydrodynamics." Physics of Plasmas 28.7 (2021).
Lin, Shan‐Chang, Yi‐Hsin Liu, and Xiaocan Li. "The spreading of magnetic reconnection X‐line in particle‐in‐cell simulations–mechanism and the effect of drift‐kink instability." Journal of Geophysical Research: Space Physics 130.2 (2025): e2024JA033494.
Recommended Citation
Lin, Shan-Chang, "Magnetic reconnection in space: from two-dimensional Magnetohydrodynamic (MHD) simulations to three-dimensional particle-in-cell (PIC) simulations" (2025). Dartmouth College Ph.D Dissertations. 364.
https://digitalcommons.dartmouth.edu/dissertations/364
