Magnetic field calculations including the impact of persistent currents in superconducting filaments

Author

Aleksa, Martin ; Russenschuck, Stephan ; Völlinger, Christine

Author_Institution

CERN, Geneva, Switzerland

Volume

38

Issue

2

fYear

2002

fDate

3/1/2002 12:00:00 AM

Firstpage

825

Lastpage

828

Abstract

The magnetic field in the coils of superconducting magnets induces so-called persistent currents in the filaments. Persistent currents are bipolar screening currents that do not decay due to the lack of resistivity. The NbTi-filaments are type II superconductors and can be described by the critical state model. This paper presents an analytical hysteresis model of the filament magnetization due to persistent currents which takes into account the changing magnetic induction inside the filament. This model is combined with numerical field computation methods, taking local saturation effects in the ferromagnetic yoke into consideration

Keywords

current density; electromagnetic induction; magnetic hysteresis; magnetisation; niobium alloys; penetration depth (superconductivity); superconducting coils; superconducting magnets; titanium alloys; type II superconductors; Bean model; NbTi; NbTi-filaments; analytical hysteresis model; bipolar screening currents; coils; critical state model; ferromagnetic yoke; filament magnetization; local saturation effects; magnetic field calculations; magnetic induction; numerical field computation methods; persistent currents; superconducting filaments; superconducting magnets; type II superconductors; Analytical models; Conductivity; Magnetic analysis; Magnetic fields; Magnetic hysteresis; Magnetization; Persistent currents; Superconducting coils; Superconducting magnets; Type II superconductors;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.996213

Filename

996213