Higher order mode damping in a pill box cavity

Author

Voelker, F. ; Lambertson, G. ; Rimmer, R.

Author_Institution

Lawrence Berkeley Lab., California Univ., CA, USA

fYear

1991

fDate

6-9 May 1991

Firstpage

687

Abstract

The authors present a method to damp the higher-order modes (HOMs) without excessive damping of the principal mode. This has been demonstrated in a pill box cavity with three slots coupled to waveguides that carry HOM energy to terminating loads. They were concerned primarily with accelerating and deflecting modes: i.e. the TM/sub mnp/ modes of order m=0 and m=1. For the strongest damping, only three m=0 and m=1 modes were detectable. These were the principal TM/sub 010/ mode, the TM/sub 011/ longitudinal mode, and the TM/sub 110/ deflecting mode. In addition, the HOM Qs and the reduction of Q for the principal mode were determined by computer calculation. The measured Q of the first longitudinal mode was 31 and of the first transverse mode 37. The maximum damping was limited by how well the waveguides could be terminated. The computer calculations for the TM/sub 011/ and TM/sub 110/ modes gives values in the range as measured.<>

Keywords

beam handling equipment; cavity resonators; nuclear electronics; TM/sub 010/ mode; TM/sub 011/ longitudinal mode; TM/sub 110/ deflecting mode; accelerating modes; computer calculation; damping; higher-order modes; pill box cavity; principal mode; slots; terminating loads; transverse mode; waveguides; Acceleration; Contracts; Damping; Frequency; Government; Impedance; Magnetic fields; Q measurement; Structural beams; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 1991. Accelerator Science and Technology., Conference Record of the 1991 IEEE

Conference_Location

San Francisco, CA, USA

Print_ISBN

0-7803-0135-8

Type

conf

DOI

10.1109/PAC.1991.164407

Filename

164407