Higher order mode damping system in the UNK RF cavity

Author

Katalev, V. ; Kudryavtsev, V. ; Sulygin, I.

Author_Institution

IHEP, Protvino, Russia

fYear

1993

fDate

17-20 May 1993

Firstpage

916

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 Z_c/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;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 1993., Proceedings of the 1993

Conference_Location

Washington, DC

Print_ISBN

0-7803-1203-1

Type

conf

DOI

10.1109/PAC.1993.308731

Filename

308731