Title :
Higher order mode damping system in the UNK RF cavity
Author :
Katalev, V. ; Kudryavtsev, V. ; Sulygin, I.
Author_Institution :
IHEP, Protvino, Russia
Abstract :
The accelerating structure of the UNK consists of two cavities, working at 200 MHz and fed by an RF power generator via a 3dB hybrid. The UNK bunched proton beam will have an extremely high intensity (6.10 14ppp) and therefore the problem of acceleration stability is a paramount one. One of the causes of instability is known to be higher order modes (HOM) excited by the beam itself in the accelerating structure. In order to eliminate the beam instability the HOM coupling impedances must be reduced to a certain threshold level. A threshold value of the coupling impedance for the first ring of the UNK is Zc /n = 6 - 16 Ω (the first ring contains 16 accelerating cavities). Here n is the HOM frequency - revolution frequency ratio. In this report the damping system reducing the cavity HOM impedances to the threshold level is described
Keywords :
beam handling equipment; cavity resonators; particle beam diagnostics; proton accelerators; storage rings; synchrotrons; 200 MHz; HOM coupling impedances; HOM frequency; RF power generator; UNK RF cavity; UNK bunched proton beam; accelerating cavities; acceleration stability; cavity HOM impedances; coupling impedance; higher order mode damping system; instability; intensity; revolution frequency ratio; Acceleration; Coaxial components; Couplings; Cutoff frequency; Damping; Impedance; Particle beams; Probes; Radio frequency; Voltage;
Conference_Titel :
Particle Accelerator Conference, 1993., Proceedings of the 1993
Conference_Location :
Washington, DC
Print_ISBN :
0-7803-1203-1
DOI :
10.1109/PAC.1993.308731
