Sennyu K.

Paper	Title	Page
MO405	Construction and Commissioning of KEKB Superconducting Crab Cavities	63
	K. Hosoyama, K. Hara, A. Honma, A. Kabe, Y. Kojima, Y. Morita, H. Nakai, K. Nakanishi, K. Akai, K. Ebihara, T. Furuya, S. Mitsunobu, M. Ono, Y. Yamamoto KEK K. Okubo, K. Sennyu, H. Hara, T. Yanagisawa MHI Kobe
	The superconducting crab cavities for KEKB were constructed and installed into KEKB electron-positron collider in January 2007. After cool-down of the crab cavities, the commissioning of the crab cavities started in February 2007 and continued until end of June. Effective head on collision of electron and positron has been achieved successfully for the first time during this spring operation of the KEKB. A luminosity of above 10^34/cm2/sec could be obtained at high beam currents operation (1.3A in the low energy positron and 0.7A in high energy electron).
	Slides(PDF)
WEP27	Horizontal tests for crab cavities in KEKB	520
	Y. Yamamoto, K. Akai, K. Ebihara, T. Furuya, K. Hara, T. Honma, K. Hosoyama, A. Kabe, Y. Kojima, S. Mitsunobu, Y. Morita, H. Nakai, K. Nakanishi, M. Ono KEK H. Hara, K. Sennyu, T. Yanagisawa MHI Kobe T. Kanekiyo HITACHI T. Nakazato JASRI
	Two Crab cavities were fabricated at KEK in 2006. After the completion of the assembly, a horizontal test is normally carried out for a superconducting cavity in KEK. The horizontal test is an overall test for the cavity without a beam. Both cavities achieved above an operational kick voltage of 1.4MV. Although the HER (High Energy Ring for electron) Crab cavity had no trouble, the LER (Low Energy Ring for positron) had a trouble of tuner operation. Due to the limited time, both cavities were installed into the tunnel at the beginning of Jan. in 2007. After the beam commissioning, it was found that this problem was not so much significant for the operation. The LER Crab cavity is being operated above 1A at present.
WEP48	Design and fabrication of superconducting cavities for industrialization	597
	K. Sennyu, H. Hara MHI Kobe M. Matsuoka MHI Hyogo
	MHI has supplied various types of superconducting cavities mainly to KEK in Japan since TRISTAN project started at 1977. We have a lot of experience in the development of superconducting cavities for Japanese projects. And we have the technology to design and fabricate the superconducting cavities. We can present some ideas to improve the quality, cost, and delivery time of the superconducting cavities based on our experience. We designed and fabricated four STF-Baseline superconducting cavities with frequency tuners, helium jackets, according to KEK specifications. To decrease a cavity deformation occurring due to Lorenz force, rigid jacket systems including tuner were designed. By fabricating four cavities, some problems and improvements in the next step are cleared. Some ideas to reduce the fabrication cost are proposed in this paper.
WEP50	Input Couplers for KEKB Crab Cavities	606
	K. Nakanishi, K. Hara, K. Hosoyama, Y. Kojima, S. Mitsunobu, Y. Yamamoto KEK K. Okihira, K. Sennyu MHI Kobe T. Tanaka Broad Wireless Corporation
	The RF input couplers for KEKB crab cavities were designed, fabricated and installed. The input coupler is shown in figure 1. The RF input coupler has a ceramic RF window and a T-stub structure. The shape of T-stub structure and length of the probe were decided using RF simulation program. The RF window and the doorknob translator may cause some reflection. The RF windows for superconducting accelerator cavities for KEKB (KEKB-SCC) and the doorknob translators for TRISTAN were used. According to the procedure of assembling the RF input coupler for KEKB-SCC, they were rinsed and assembled. Aging was done individually. After that, they were installed into cryostats for crab cavities. These cryostats were installed to KEKB and have been working. Three input couplers, which are included for prototype cryostat, were prepared.