Title :
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
fDate :
3/1/1989 12:00:00 AM
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;
Journal_Title :
Magnetics, IEEE Transactions on
