BYU

Abstract by Alden Pack

Personal Infomation


Presenter's Name

Alden Pack

Co-Presenters

None

Degree Level

Doctorate

Co-Authors

None

Abstract Infomation


Department

Physics and Astronomy

Faculty Advisor

Mark Transtrum

Title

Estimating the Superconducting Superheating Field in Time-Dependent Ginzburg-Landau Theory using Bifurcation Analysis

Abstract

The expulsion of magnetic fields, or Meissner effect, is a hallmark of superconductivity. In the presence of an applied magnetic field, the Meissner state is thermodynamically stable up to a critical magnetic field (Hc for type I superconductors and Hc1 for type II superconductors). However, the Meissner state may persist as a metastable state up to the "superheating field", Hsh. Understanding the dependence of Hsh on material and geometry is an important question for improving performance of particle accelerators. We numerically study the superheating transition in time-dependent Ginzburg-Landau theory using finite-element methods. At the superheating field, the equations exhibit a saddle-node bifurcation. We use techniques from numerical analysis of dynamical systems to estimate Hsh. We estimate the time for the system to equilibrate at small values of the applied field and extrapolate to where the equilibration time diverges. We explore the dependence on Hsh on material and geometric properties of interest in accelerator physics.