Study of time dependent magnetic field variation due to current redistribution in Rutherford cable

Author

Sugita, Kei ; Ogitsu, Toru ; Ohuchi, Norihito ; Nakamoto, Tatsushi ; Shintomi, Takakazu ; Tsuchiya, Kiyosumi ; Yamamoto, Akira

Author_Institution

Dept. of Accelerator Sci., Graduate Univ. for Adv. Studies, Ibaraki, Japan

Volume

14

Issue

2

fYear

2004

fDate

6/1/2004 12:00:00 AM

Firstpage

255

Lastpage

258

Abstract

Time-varying magnetic field quality of superconducting accelerator magnets is a important issue of accelerator operation at particle injection. This is induced by magnetization changes of superconductors due to redistributions of imbalance current of superconducting strands in cables. Because the imbalance current and its redistributions induce time variations of magnetic periodic patterns, to clarify the mechanism of time-varying magnetic field, we performed periodic pattern measurements on quadrupole magnets for the LHC insertion regions developed by KEK in collaboration with CERN. We report the results of the measurements with various excitation processes, and describe estimation of imbalance current using numerical calculation.

Keywords

accelerator magnets; colliding beam accelerators; magnetic field measurement; magnetisation; proton accelerators; storage rings; superconducting magnets; synchrotrons; CERN; KEK; LHC insertion regions; Rutherford cable; accelerator magnets; accelerator operation; current redistribution; excitation process; imbalance current; large hadron collider; magnetic periodic patterns; magnetization change; particle injection; periodic pattern measurements; quadrupole magnets; superconducting magnets; superconducting strands; superconductors; time dependent magnetic field variation; time-varying magnetic field; Accelerator magnets; Current measurement; Magnetic field measurement; Magnetic fields; Magnetization; Particle accelerators; Performance evaluation; Superconducting cables; Superconducting magnets; Superconductivity; Imbalance current; periodic pattern; superconducting accelerator magnet; time-varying field quality;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2004.829065

Filename

1324784