Studies of time dependence of fields in Tevatron superconducting dipole magnets

Author

Hanft, W. ; Brown, B.C. ; Herrup, D.A. ; Lamm, M.J. ; McInturff, A.D. ; Syphers, M.J.

Author_Institution

Fermi Nat. Accel. Lab., Batavia, IL, USA

Volume

25

Issue

2

fYear

1989

fDate

3/1/1989 12:00:00 AM

Firstpage

1647

Lastpage

1651

Abstract

The time variation in the magnetic field of a model Tevatron dipole magnet at constant excitation current has been studied. Variations in symmetry allowed harmonic components over long time ranges show a log t behavior indicative of `flux creep´. Both short-time-range and long-time-range behavior depend on the excitation history. Similar effects are seen in the remnant fields present in full-scale Tevatron dipoles following current ramping. Both magnitudes and time dependences are observed to depend on details such as ramp rate, flattop duration, and number of ramps. In a few magnets, variations are also seen in symmetry-disallowed harmonics

Keywords

superconducting magnets; synchrotrons; Tevatron superconducting dipole magnets; constant excitation current; current ramping; excitation history; flattop duration; flux creep; full-scale Tevatron dipoles; harmonic components; log t behavior; long term behaviour; long time ranges; magnetic field time variation; magnitude dependence of fields; model Tevatron dipole magnet; number of ramps; ramp rate; remnant fields; short term behaviour; short-time-range; symmetry-disallowed harmonics; time dependence of fields; Accelerator magnets; Critical current; Gaussian processes; Iron; Magnetic fields; Packaging; Superconducting cables; Superconducting coils; Superconducting epitaxial layers; Superconducting magnets;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.92616

Filename

92616