• S. H. Kim, C. Doose
  ANL, Argonne, Illinois

Model superconducting helical undulators are under development for the proposed International Linear Collider (ILC) positron source. The undulator requires high-permeability steel poles and superconducting coils to meet the ILC parameters. A fabrication method for steel poles on a nonmagnetic beam chamber was developed. A model undulator with a period length of 14 mm and Nb3Sn coils was fabricated. Both ends of the model were designed to provide for continuous winding of a single conductor with 39 turns per helix. A 10-mm-period model was designed and is in the fabrication process. The 14-mm-period model may be used in the development of a cryogenic magnetic measurement system. Details of the fabrication and test results will be presented.

• H. R. Yang, M.-H. Cho, S. H. Kim, S.-I. Moon, W. Namkung
  POSTECH, Pohang, Kyungbuk
• S. D. Jang, S. J. Kwon, J.-S. Oh, S. J. Park, Y. G. Son
  PAL, Pohang, Kyungbuk

An intense L-band electron accelerator is now being installed at PAL (Pohang Accelerator Laboratory) for initial tests. It is capable of producing 10-MeV electron beams with average 30 kW. This accelerator has a diode-type E-gun, a pre-buncher cavity, and an accelerating column with the built-in bunching section. We conduct simulational study for the commissioning scenario by the PARMELA code. At first, we observe the beam position and the beam current when the beam line is misaligned under no fields. Next, turning on focusing solenoids we observe the beam position change to check the alignments of the solenoids. Finally, varying RF power and phase of the pre-buncher we observe beam energy and beam power to obtain the optimum pre-buncher condition. In this paper, we present simulational results for each step. We also present commissioning strategies based on these results.

• S. H. Kim, M.-H. Cho, Y. M. Gil, S.-I. Moon, W. Namkung, H. R. Yang
  POSTECH, Pohang, Kyungbuk
• J. Jang, J.-S. Oh, S. J. Park
  PAL, Pohang, Kyungbuk

For a compact X-ray source, we designed a C-band standing-wave electron accelerator. It is capable of producing 4-MeV electron beams with 50-mA peak beam current. As an RF source, we use 5-GHz magnetron with duty factor of 0.08%. The accelerating structure is bi-periodic and on-axis coupled structure, operated with π/2-mode standing waves. Each cavity in the bunching and normal cell is designed by the MWS code and measured with aluminium prototype cavity. As per the dispersion relation derived from the measurement results, calibration factor obtained for the actual copper cavity.

• S. H. Kim, M.-H. Cho, W. Namkung, H. R. Yang
  POSTECH, Pohang, Kyungbuk
• S. D. Jang, S. J. Kwon, J.-S. Oh, S. J. Park, Y. G. Son
  PAL, Pohang, Kyungbuk

An intense L-band electron accelerator is designed and under development for CESC (Cheorwon Electron-beam Service Center) irradiation applications. It is capable of producing 10-MeV electron beams with average 30 kW. For an RF source, a Thales klystron is used with 1.3 GHz, pulsed 25 MW, and average 60 kW. The accelerator column, fabricated by IHEP in China, is operated with 2π/3 mode traveling-wave under the fully-beam-loaded condition. The modulator was fabricated with inverter power supplies. The klystron was assembled to the klystron tank with pulse transformer. The high-voltage pulse test was conducted for the klystron tube. In this paper, we present design details of the accelerator and current status.

• 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.