HOM damping performance of JLab SL21 cryomodule

Author

Wang, Huifang ; Campisi, I. ; Beard, K. ; Rimmer, Robert ; Thomas, C. ; Mammosser, J. ; Preble, J.

Author_Institution

TJNAF, Newport News, VA, USA

Volume

2

fYear

2003

fDate

12-16 May 2003

Firstpage

1104

Abstract

The SL21 cryomodule is a first 1.5 GHz, 12.5 MV/m, 7-cell cavity, 8-cavity string superconducting accelerator module produced at JLab. The first two passbands of TE111 and TM110 high order modes (HOM) have to be damped to avoid beam breakup problems at 460 μA current. External Q´s of the HOM couplers and waveguide were measured on a copper model, on cold niobium cavities in vertical tests and finally in the cryomodule without beam. This paper presents all HOM data and general measurement techniques. A threshold current predicted by MATBBU code based on these data and the 6 GeV machine beam optics is 10 mA.

Keywords

accelerator cavities; superconducting cavity resonators; 1.5 GHz; 10 mA; 460 muA; 6 GeV; 8-cavity string superconducting accelerator module; HOM couplers; HOM damping; HOM waveguide; JLab SL21 cryomodule; MATBBU code; TE111 high order mode; TM110 high order mode; beam breakup problems; cold niobium cavities; copper model; machine beam optics; Copper; Couplers; Damping; Measurement techniques; Niobium; Optical beams; Optical waveguides; Passband; Testing; Threshold current;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 2003. PAC 2003. Proceedings of the

ISSN

1063-3928

Print_ISBN

0-7803-7738-9

Type

conf

DOI

10.1109/PAC.2003.1289619

Filename

1289619