Title :
The eddy-current-induced head-tail instability at the KEK-PS
Author :
Toyama, T. ; Arakawa, D. ; Igarashi, S. ; Kishiro, J. ; Nakamura, E. ; Takayama, K.
Author_Institution :
KEK, Ibaraki, Japan
Abstract :
The head-tail instability of the 12 GeV PS at KEK, has been confirmed by extensive experiments. It turns out that the eddy-current-induced sextupole fields in the rectangular-shaped vacuum pipe in the main bending magnets played a crucial role in the head-tail instability during acceleration. The eddy current effect was verified by field measurement and chromaticity measurement in a way of different field-rampings. The coupling impedances of the present injection kickers and new fast-extraction (FX) kickers, the dominant impedance sources, have been examined on the test bench. The growth rate is calculated
Keywords :
colliding beam accelerators; eddy currents; particle beam stability; proton accelerators; synchrotrons; KEK-PS; chromaticity measurement; coupling impedances; eddy-current-induced head-tail instability; eddy-current-induced sextupole fields; fast-extraction kickers; field measurement; injection kickers; main bending magnets; rectangular-shaped vacuum pipe; Acceleration; Current measurement; Eddy currents; Impedance; Magnetic field measurement; Magnets; Particle measurements; Probes; Smoothing methods; Time measurement;
Conference_Titel :
Particle Accelerator Conference, 1999. Proceedings of the 1999
Conference_Location :
New York, NY
Print_ISBN :
0-7803-5573-3
DOI :
10.1109/PAC.1999.795475
