Title :
Time decay measurements of the sextupole component of the magnetic field in a 4-cm aperture, 17-m-long SSC dipole magnet prototype
Author :
Devred, A. ; DiMarco, J. ; Kuzminski, J. ; Stiening, R. ; Tompkins, J. ; Yu, Y. ; Zheng, H. ; Ogitsu, T. ; Hanft, R. ; Mazur, P.O. ; Orris, D. ; Peterson, T.
Author_Institution :
Superconducting Super Collider Lab., Dallas, TX, USA
Abstract :
A systematic series of measurements of the time decay of the sextupole component of the magnetic field in a full-length SSC (Superconducting Super Collider) dipole magnet prototype was carried out in order to characterize the mechanisms involved. At least two mechanisms have been isolated. The first is a slow logarithmic decay which is independent of the excitation history of the magnet. This component is stopped by a decrease of the magnet temperature and is identified with flux creep. The second component, which is not yet fully understood, only appears when the magnet is pre-cycled to a high level of current, and cannot be stopped by decreasing the magnet temperature. The first component is attributed to flux creep in the superconductor. The authors are currently developing a model of demagnetization caused by shifting/transport currents in the superconducting cables that could account for the secondary component.<>
Keywords :
proton accelerators; storage rings; superconducting magnets; synchrotrons; SSC dipole magnet prototype; Superconducting Super Collider; demagnetization; excitation history; flux creep; shifting/transport currents; slow logarithmic decay; superconducting cables; Creep; Demagnetization; History; Magnetic field measurement; Magnetic flux; Prototypes; Superconducting cables; Superconducting magnets; Temperature; Time measurement;
Conference_Titel :
Particle Accelerator Conference, 1991. Accelerator Science and Technology., Conference Record of the 1991 IEEE
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
0-7803-0135-8
DOI :
10.1109/PAC.1991.165006
