Title :
Reducing beam coupling impedances in SNS ring extraction kickers
Author :
Kurennoy, S.S. ; Davino, D. ; Lee, Y.Y.
Author_Institution :
Los Alamos Nat. Lab., NM, USA
Abstract :
The Spallation Neutron Source (SNS) Accumulator ring extraction system includes 14 modules of window-frame ferrite pulsing kicker magnets with the rise time of about 200 ns. Their contribution to the beam coupling impedances is a serious concern. The kicker impedances, as well as its deflecting magnetic field versus time, are studied using detailed 3-D MAFIA modeling. Various design options, external circuit resistances, and a range of ferrite permeabilities are explored. A kicker module with wide conductor windings around the ferrite behind the kicker current sheet suggests a significant reduction of the kicker transverse and longitudinal coupling impedances. This design provides a good extraction field performance, as demonstrated by electromagnetic simulations. Results of measurements for a small model are also presented
Keywords :
accelerator magnets; electromagnets; ferrites; high energy physics instrumentation computing; neutron sources; particle beam diagnostics; particle beam extraction; proton accelerators; proton beams; storage rings; 200 ns; MAFIA code; SNS ring extraction kickers; Spallation Neutron Source; accumulator ring extraction system; beam coupling impedance reduction; conductor windings; deflecting magnetic field; electromagnetic simulations; external circuit resistances; fast extraction kicker magnets; kicker impedance; proton beam; window-frame ferrite pulsing kicker magnets; Conductors; Coupling circuits; Electromagnetic fields; Ferrites; Impedance; Magnetic fields; Magnets; Neutrons; Optical coupling; Permeability;
Conference_Titel :
Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-7191-7
DOI :
10.1109/PAC.2001.987200
