• Y. U. Sohn, J. Choi, M.-H. Chun, J. Y. Huang, I. S. Ko, I. S. Park
  PAL, Pohang, Kyungbuk

Pohang Accelerator Laboratory has prepared to SRF 3rd harmonic cavity to increase beam lifetime and to damp orbit instability by lengthening electron bunch in PLS. The SRF cavity was developed and its vertical test was done already with success. Higher order modes were analyzed to optimize its performance in beam orbit. Most of them are not effective to electron beam, while the others have possibility to impact orbit stability. These harmful HOMs can be removed by HOM absorber installed in beam pipe. This paper reports the HOM analysis and design of its removal system.

• I. S. Park, J. Choi, C. W. Chung, M.-S. Hong, W. H. Hwang, D. T. Kim, Y. C. Kim, I. S. Ko, H. C. Kwon, Y. U. Sohn
  PAL, Pohang, Kyungbuk
• S. W. Kim, S. H. Kim, S. K. Song
  RIST, Pohang

Pohang Accelerator Laboratory has studied SRF cavity and set up SRF test laboratory from January 2006. The first activity for SRF research was to develop SRF 3rd harmonic cavity for Pohang Light Source, which was designed, fabricated and tested in 2006. The cryostat are under design. The fabrication of ICHIRO cavity, which is ILC ACD cavity, is PAL's second activity related to SRF. Deep drawing, trimming and welding by electron beam for a 9-cell ICHIRO cavity were done in PAL. The polishing processes for the RF surface including electropolishing were done in KEK under the collaboration between two institutes. This will be tested with real beam in STF-1 of KEK in second half period of 2007. This paper reports the results of fabrication of ICHIRO single- and nine-cell cavities performed in PAL.