Experiment of the RF feedback using a parallel comb filter

Author

Yoshimoto, S. ; Ezura, E. ; Akai, K. ; Takashima, T.

Author_Institution

KEK, Nat. Lab. for High Energy Phys., Ibaraki, Japan

Volume

4

fYear

1995

fDate

1-5 May 1995

Firstpage

2675

Abstract

In high beam-current storage rings like KEK B-factory, severe coupled-bunch longitudinal instability can be driven by the accelerating mode of significantly detuned RF cavities. The RF feedback with a comb filter, which can reduce the effective cavity impedance at the synchrotron sidebands of the revolution harmonics, is a possible way to damp the instability. This paper describes the results of the experimental RF feedback loop, which includes a N-path filter referred to as a parallel comb filter, a choke mode cavity, and a 1.2 MW klystron. With the feedback, the real part of the cavity impedance was reduced by 16 dB to 24 dB, at the five synchrotron sidebands 100 kHz apart each other

Keywords

accelerator RF systems; accelerator control systems; beam handling techniques; colliding beam accelerators; electron accelerators; feedback; harmonics; storage rings; KEK B-factory; N-path filter; RF feedback; choke mode cavity; effective cavity impedance; high beam-current storage rings; klystron; parallel comb filter; revolution harmonics; severe coupled-bunch longitudinal instability; significantly detuned RF cavities; synchrotron sidebands; Acceleration; Feedback loop; Impedance; Inductors; Klystrons; Optical coupling; Power harmonic filters; Radio frequency; Storage rings; Synchrotrons;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 1995., Proceedings of the 1995

Conference_Location

Dallas, TX

Print_ISBN

0-7803-2934-1

Type

conf

DOI

10.1109/PAC.1995.505656

Filename

505656