PAC 2005 - List of Authors

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Ohuchi, N.

Paper	Title	Page
MPPT037	Design Study of Superconducting Magnets for the Super-KEKB Interaction Region	2470
	N. Ohuchi, Y. Funakoshi, H. Koiso, K. Oide, K. Tsuchiya KEK, Ibaraki
	The KEKB accelerator has achieved the highest luminosity of 1.39E10³⁴cm-2s-1 at June-03-2004. For getting the higher luminosity over 1E10³⁵cm-2s-1, the KEKB accelerator group continues to study the upgraded machine of the KEKB, that is the Super-KEKB. The designed machine parameters for this Super-KEKB are the vertical beta of 3 mm at the interaction point (IP), the LER and HER currents of 9.4 A and 4.1 A, and the half crossing angle of 15 mrad for the target luminosity of 1-5E10³⁵cm-2s-1. For achieving these beam parameters, the superconducting magnets (final focus quadrupoles and compensation solenoids) are newly required to design. The magnet-cryostats have very tight spatial constraints against the Belle particle detector and the beam pipe so that the beam and the synchrotron light do not have any interference with the beam pipe. In this design, the final focus quadrupoles generate the field gradient of 42.3 T/m and their effective magnetic lengths are 0.30m and 0.36m in each side with respect to the IP, respectively. The compensation solenoids are overlaid with the quadrupoles. We will report the design of these magnets in detail and show the difficulties for the Super-KEKB-IR.
MPPT044	The Construction of the Low-Beta Triplets for the LHC	2798
	R. Ostojic, M. Karppinen, T.M. Taylor, W. Venturini Delsolaro CERN, Geneva R. Bossert, J. DiMarco, SF. Feher, J.S. Kerby, M.J. Lamm, T.H. Nicol, A. Nobrega, T.M. Page, T. Peterson, R. Rabehl, P. Schlabach, J. Strait, C. Sylvester, M. Tartaglia, G. Velev Fermilab, Batavia, Illinois N. Kimura, T. Nakamoto, T. Ogitsu, N. Ohuchi, t.s. Shintomi, K. Tsuchiya, A. Yamamoto KEK, Ibaraki
	The performance of the LHC depends critically on the low-beta triplets, located on either side of the four interaction points. Each triplet consists of four superconducting quadrupole magnets, which must operate reliably at up to 215 T/m, sustain extremely high heat loads and have an excellent field quality. A collaboration of CERN, Fermilab and KEK was set up in 1996 to design and build the triplet systems, and after nine years of joint effort the production will be completed in 2005. We retrace the main events of the project and present the design features and performance of the low-beta quadrupoles, built by KEK and Fermilab, as well as of other vital elements of the triplet. The experience in assembly of the first triplet at CERN and plans for tunnel installation and commissioning in the LHC are also presented. Apart from the excellent technical results, the construction of the LHC low-beta triplets has been a highly enriching experience combining harmoniously the different competences and approaches to engineering in a style reminiscent of physics experiment collaborations, and rarely before achieved in accelerator building.
TPPT062	High Power Test of the Prototype Cryomodule for ADS Superconducting Linac	3579
	E. Kako, S. Noguchi, N. Ohuchi, T. Shishido, K. Tsuchiya KEK, Ibaraki N. Akaoka, H. Kobayashi, N. Ouchi JAERI/LINAC, Ibaraki-ken E. Chishiro, T. Hori, M. Nakata, M. Yamazaki JAERI, Ibaraki-ken
	A prototype cryomodule containing two 9-cell superconducting cavities of beta=0.725 and fo=972MHz had been constructed under the collaboration of Japan Atomic Energy Research Institute (JAERI) and High Energy Accelerator Research Organization (KEK) on the development of superconducting LINAC for Accelerator Driven System (ADS). Cool-down tests to 2.0K of the cryomodule and high power tests with a 972MHz pulsed klystron have been successfully carried out. Rf power of 350kW in a pulsed operation of 3msec and 25Hz was transferred to the nine-cell cavity through an input coupler. Accelerating gradients of about 14MV/m higher than the specification (10MV/m) were achieved in both cavities. Design and performance of the prototype cryomodule and the test results with high rf power will be reported.
TPPP007	Recent Progress at KEKB	1045
	Y. Funakoshi, K. Akai, K. Ebihara, K. Egawa, A. Enomoto, J.W. Flanagan, H. Fukuma, K. Furukawa, T. Furuya, J. Haba, S. Hiramatsu, T. Ieiri, N. Iida, H. Ikeda, T. Kageyama, S. Kamada, T. Kamitani, S. Kato, M. Kikuchi, E. Kikutani, H. Koiso, M. Masuzawa, T. Mimashi, A. Morita, T.T. Nakamura, H. Nakayama, Y. Ogawa, K. Ohmi, Y. Ohnishi, N. Ohuchi, K. Oide, M. Ono, M. Shimada, S. Stanic, M. Suetake, Y. Suetsugu, T. Sugimura, T. Suwada, M. Tawada, M. Tejima, M. Tobiyama, N. Tokuda, S. Uehara, S. Uno, N. Yamamoto, Y. Yamamoto, Y. Yano, K. Yokoyama, M. Yoshida, M. Yoshida, S.I. Yoshimoto KEK, Ibaraki F. Zimmermann CERN, Geneva
	We summarize the machine operation of KEKB during past one year. Progress for this period, causes of present performance limitations and future prospects are described.
RPPE052	Application of Comb-Type RF-Shield to Bellows Chambers and Gate Valves	3203
	Y. Suetsugu, K.-I. Kanazawa, N. Ohuchi, K. Shibata, M. Shirai KEK, Ibaraki
	A comb-type RF-shield, which was recently proposed for high current accelerators, was experimentally applied to bellows chambers and gate valves. The comb-type RF-shield has a structure of nested comb teeth, and has higher thermal strength and lower impedance than usual finger-type RF shields. The shield is suitable for future high intensity accelerators, such as particle factories aiming a luminosity of 1·10³⁵ - 36 /cm² /s. Seven bellows chambers with a circular or a racetrack cross section had been installed in the KEKB (KEK B-factory) positron ring since 2003 in series. Some bellows chambers are forced to bend up to 20 mrad during the beam operation. No significant problem had been found with a stored beam current up to 1.6 A (1.25 mA/bunch). On the other hand, a circular-type gate valve with the comb-type RF shield will be installed in the ring in January, 2005. Structures, properties and results of the beam test of the bellows chamber and the gate valve are discussed.
RPPE053	R&D Status of Vacuum Components for the Upgrade of KEKB	3256
	Y. Suetsugu, H. Hisamatsu, K.-I. Kanazawa, N. Ohuchi, K. Shibata, M. Shirai KEK, Ibaraki
	An upgrade plan of the KEK B-factory (KEKB), Super KEKB, aiming a luminosity over 1·10³⁵ /cm² /s has been discussed in KEK. To achieve the high luminosity, the stored beam currents are 4.2 - 9.4 A and the bunch length is 3 mm. In designing the vacuum system of the Super KEKB, therefore, the main issues are how to manage the resultant highly intense synchrotron radiation (SR) power, and how to reduce the beam impedance. The R&Ds for basic vacuum components, such as a beam duct, a bellows chamber, a connection flange, a collimator, a high-capacity pump and so on, are now undergoing to deal with the problems. For examples, a copper beam duct with an antechamber was manufactured to reduce the power density of SR, and to suppress the electrons around the beam for the positron ring. The test chamber was installed in the positron ring of KEKB and tested with a beam. Bellows chambers with a newly developed RF-shield were also installed in the ring and the property was investigated. A special connection flange with little step or gap inside was developed and examined in a test bench. The designs of these components and the results of tests are presented and discussed.