DocumentCode :
1975682
Title :
Axial variations in the magnetic field of superconducting dipoles and quadrupoles
Author :
Ghosh, A.K. ; Robins, K.E. ; Sampson, W.B.
Author_Institution :
Brookhaven Nat. Lab., Upton, NY, USA
fYear :
1993
fDate :
17-20 May 1993
Firstpage :
2742
Abstract :
A periodic variation in the magnetic field along the axis has been observed in both quadrupole and dipole magnets made from superconducting cable. This oscillation is present in all components of the field and has a wavelength equal to the transposition length of the cable. In general the amplitude of these variations increases with magnet current and is not reversible. The residual field pattern at zero current depends on the energizing cycle and increases with time spent at high field. The decay of the oscillations has a complex time dependence which contains some extremely long time constants. Unbalanced currents in the individual strands of the cable appear to cause these effects and the field variations can only be completely erased by raising the magnet above its critical temperature
Keywords :
beam handling equipment; superconducting magnets; axial variations; complex time dependence; critical temperature; energizing cycle; field variations; magnet current; magnetic field; oscillation decay; periodic variation; residual field pattern; superconducting cable; superconducting dipoles; superconducting quadrupoles; time constants; transposition length; unbalanced currents; Gaussian approximation; Gaussian processes; Laboratories; Magnetic field measurement; Magnetic fields; Power supplies; Prototypes; Superconducting cables; Superconducting magnets; Temperature;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Particle Accelerator Conference, 1993., Proceedings of the 1993
Conference_Location :
Washington, DC
Print_ISBN :
0-7803-1203-1
Type :
conf
DOI :
10.1109/PAC.1993.309446
Filename :
309446
Link To Document :
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