New measurements of magnetic field decay in 1 meter SSC-type dipoles

Author

Gilbert, W.S. ; Althaus, R.F. ; Barale, P.J. ; Benjegerdes, R.W. ; Green, M.A. ; Green, M.I. ; Scanlan, R.M.

Author_Institution

Lawrence Berkeley Lab., California Univ., CA, USA

Volume

27

Issue

2

fYear

1991

fDate

3/1/1991 12:00:00 AM

Firstpage

1965

Lastpage

1968

Abstract

Previous studies of magnetic field decay in model SSC (Superconducting Super Collider) dipoles due to changes in magnetization currents caused by flux creep have used the assumed SSC injection energy of 1 TeV, or an 0.33-T central dipole field, and an excitation to the storage field of 6.6 T. More recently, it has been decided to inject at 2 TeV, or 0.66 T and so more recent tests have been carried out at the new injection field, or at both the new and old fields. Additionally, the effects of temperature changes and excitation cycles on the field decay have been studied. The roughly log linear decay of magnetization current multipole fields has been demonstrated in several new dipoles. A suggested mechanism of thermally induced activation in the additional 0.5-K range has been effectively countered by temperature measurements that show temperature fluctuation ten to thirty times lower, over a 90-min time period

Keywords

beam handling equipment; magnetic fields; proton accelerators; storage rings; superconducting magnets; synchrotrons; 0.66 T; 1 m; SSC-type dipoles; Superconducting Super Collider; excitation cycles; flux creep; injection field; log linear decay; magnetic field decay; magnetization currents; multipole fields; temperature changes; thermally induced activation; Fluctuations; Glass; Helium; Laboratories; Magnetic field measurement; Magnetic flux; Magnetic sensors; Magnetization; Temperature sensors; Testing;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.133589

Filename

133589