Title :
HOM RF cavity dampers for suppressing coupled bunch instabilities in the Fermilab Booster
Author :
Wildman, D. ; Harkay, K.
Author_Institution :
Fermi Nat. Accel. Lab., Batavia, IL, USA
Abstract :
The coupled bunch mode n=16 longitudinal instability observed in the Fermilab Booster has been successfully damped by installing a set of passive higher-order mode (HOM) dampers in the 17 Booster RF cavities. The Booster is a fast cycling 8 GeV proton synchrotron with harmonic number 84. The dampers remove energy from two cavity modes at 165 and 217 MHz. The addition of these dampers to the RF cavities has reduced the longitudinal emittance of high current beams at extraction by a factor of 3. The mode dampers will be described along with beam spectra and data showing the longitudinal emittance reduction
Keywords :
beam handling techniques; cavity resonators; particle beam diagnostics; proton accelerators; synchrotrons; 165 MHz; 217 MHz; 8 GeV; Fermilab Booster; HOM RF cavity dampers; RF cavity dampers; coupled bunch instabilities; coupled bunch mode; higher-order mode dampers; longitudinal emittance; n=16 longitudinal instability; proton synchrotron; Acceleration; Ferrites; Flexible printed circuits; Frequency measurement; Impedance measurement; Monitoring; Optical coupling; Particle beams; Radio frequency; Spectral analysis;
Conference_Titel :
Particle Accelerator Conference, 1993., Proceedings of the 1993
Conference_Location :
Washington, DC
Print_ISBN :
0-7803-1203-1
DOI :
10.1109/PAC.1993.309618
