Title :
Open loop compensation for the eddy current effect in the APS storage ring vacuum chamber
Author :
Chung, Y. ; Bridges, J. ; Emery, L. ; Decker, G.
Author_Institution :
Argonne Nat. Lab., IL, USA
Abstract :
Results of the effort to counter the effect due to the finite inductance of the magnet and the eddy current in the 1/2-in-thick aluminum storage ring vacuum chamber are presented. The amplitude attenuation and the phase shift of the correction magnet field inside the APS storage ring vacuum chamber were measured. A circuit to compensate for this effect was then inserted between the signal source and the magnet power supply. The amplitude was restored with an error of less than 20% of the source signal amplitude and the phase shift was reduced from 80 degrees to 12 degrees at 10 Hz. Incorporation of this circuit in the closed-loop feedback scheme and the resulting beneficial effect in the closed-orbit stabilization is discussed.<>
Keywords :
beam handling equipment; storage rings; APS storage ring vacuum chamber; amplitude attenuation; closed-loop feedback scheme; closed-orbit stabilization; correction magnet field; eddy current effect; finite inductance; magnet; phase shift; Aluminum; Attenuation measurement; Counting circuits; Eddy currents; Inductance; Magnetic circuits; Magnetic field measurement; Phase measurement; Power supplies; Storage rings;
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.1991.164691
