The DTL/SDTL alignment of the J-PARC linac

Morishita, Takatoshi; Asano, Hiroyuki; Ito, Takashi; Ueno, Akira; Hasegawa, Kazuo; Naito, Fujio*; Takasaki, Eiichi*; Tanaka, Hirokazu*; Yoshino, Kazuo*; Ikegami, Masanori*

Proceedings of 2007 Particle Accelerator Conference (PAC '07) (Internet), p.1523 - 1525, 2007/06

J-PARC linear accelerator components have been installed. The required alignment accuracy in the J-PARC linac is 0.1mm in transverse direction. In the DTL/SDTL section, the fine alignment was carried out by using an optical alignment telescope along with the cavity installation. The displacement of the DTL by the unit tank connection was monitored by a laser tracker to obtain the tolerable displacement between unit tanks. The heights of cavities and magnets were compensated form the unequal ground movement of the linac tunnel. Finally, all the cavities and magnets are aligned within the tolerable alignment error.

RF characteristics of the SDTL for the J-PARC

Ito, Takashi; Asano, Hiroyuki; Morishita, Takatoshi; Yamazaki, Yoshishige; Tanaka, Hirokazu*; Naito, Fujio*; Kato, Takao*; Takasaki, Eiichi*

Proceedings of 23rd International Linear Accelerator Conference (LINAC 2006) (CD-ROM), p.740 - 742, 2007/00

For the J-PARC (Japan Proton Accelerator Research Complex) linac, an SDTL (Separated type Drift Tube Linac) is used to accelerate an H ion beam from 50 MeV to 191 MeV. We have measured the RF characteristics of the SDTL tanks and adjusted the field distribution. The measured Q value was above 90% of an ideal SUPERFISH value. Furthermore the field distribution was adjusted within 1% for all the tanks.

DTL/SDTL installation and alignment of J-PARC LINAC

Morishita, Takatoshi; Asano, Hiroyuki; Ito, Takashi; Ikegami, Masanori*; Takasaki, Eiichi*; Tanaka, Hirokazu*; Naito, Fujio*; Yoshino, Kazuo*

Proceedings of 3rd Annual Meeting of Particle Accelerator Society of Japan and 31st Linear Accelerator Meeting in Japan (CD-ROM), p.376 - 378, 2006/00

In the J-PARC Linac, the DTL and the SDTL have been installed. A precise alignment of accelerator components is essential for high quality beam acceleration. Due to the heavy wiring for DTQs, the realignment of DTL cavity requires a long term. Then the DTL/SDTL and the focusing magnets are aligned precisely enough for the beam operation at the installation. The DTL/SDTL alignment accuracy satisfied the requirement, which confirmed by the laser tracker measurement. The floor level of the accelerator tunnel has been measured periodically. The long term motion of accelerator tunnel is quantitatively evaluated since Feb. 2005.

RF characteristics of J-PARC DTL3 cavity

Ito, Takashi; Asano, Hiroyuki*; Morishita, Takatoshi; Kato, Takao*; Takasaki, Eiichi*; Tanaka, Hirokazu*; Yoshino, Kazuo*; Naito, Fujio*

Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan, p.242 - 244, 2005/07

The third Drift Tube Linac (DTL3) is adopted for 37MeV-50MeV part of high intensity proton linac for Japan Proton Accelerator Research Complex(J-PARC). DTL3 consists of 26 full drift tubes, 2 half drift tubes and 26 post-couplers. As a result of tuning of the accelerating field of the DTL3, the resonant frequency was adjusted to 324MHz and the average accelerating field distribution was adjusted within 1%.

Extra radiation hardening and microstructural evolution in F82H by high-dose dual ion irradiation

Ando, Masami; Wakai, Eiichi; Sawai, Tomotsugu; Matsukawa, Shingo; Naito, Akira*; Jitsukawa, Shiro; Oka, Keiichiro*; Tanaka, Teruyuki*; Onuki, Somei*

JAERI-Review 2004-025, TIARA Annual Report 2003, p.159 - 161, 2004/11

https://jopss.jaea.go.jp/pdfdata/JAERI-Review-2004-025-p0117-p0247.pdf

The objectives of this study are to evaluate radiation hardening on ion-irradiated F82H up to 100 dpa and to examine the extra component of radiation hardening due to implanted helium atoms (up to 3000 appmHe) in F82H under ratio of 0, 10, 100 appmHe/dpa.The ion-beam irradiation experiment was carried out at the TIARA facility of JAERI. Specimens were irradiated at 633 K by 10.5 MeV Fe ions with/without 1.05 MeV He ions. Micro-indentation tests were performed at loads to penetrate about 0.40 mm in the irradiated specimens using an UMIS-2000. The results are summarized as follows:1) As a result of the single irradiated F82H, the micro-hardness tended to increase about 30 dpa. 2) The extra radiation hardening was obviously caused by co-implanted helium atoms more than 1000 appm in F82H irradiated at 633 K. 3) In the dual-beam (100 appmHe/dpa) irradiated microstructure, nano-voids and fine defects were observed. It is suggested that the formation of nano-voids causes the extra radiation hardening by helium co-implantation.

Beam commissioning of the J-PARC linac DTL1 at KEK

Kondo, Yasuhiro; Akikawa, Hisashi; Anami, Shozo*; Asano, Hiroyuki*; Fukui, Yuji*; Igarashi, Zenei*; Ikegami, Kiyoshi*; Ikegami, Masanori*; Ito, Takashi; Kawamura, Masato*; et al.

Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.156 - 158, 2004/08

A commissioning of the J-PARC linac DTL1 is now under way at KEK. A 30mA H beam was accelerated to 19.7-MeV, and 100% transmission was obtained with a 20-msec-pulse-width and 12.5-Hz-repetition beam. In this paper, present status of the DTL1 commissioning and preliminary results of the commissioning, such as emittance measurements, are presented.

Swelling behavior of TIG-welded F82H IEA heat

Sawai, Tomotsugu; Wakai, Eiichi; Tomita, Takeshi; Naito, Akira; Jitsukawa, Shiro

Journal of Nuclear Materials, 307-311(Part1), p.312 - 316, 2002/12

https://doi.org/10.1016/S0022-3115(02)01200-X

TIG-weld joints of the IEA heat of F82H were irradiated by TIARA. Transmission electron microscope (TEM) specimens were prepared by a focused ion beam (FIB) system. TEM specimens were obtained from the heat affected zone (HAZ) and the weld metal. HAZ specimens had typical bi-modal cavity microstructure after 50 dpa at 450C with He/dpa ratio of 10 appmHe/dpa. Larger voids about 30 nm were observed in the tempered side specimen, while the size of voids in the quenched side specimen was less than 15 nm. Ac1 temperature determined by heat-treated base metal is 820C. Cavity growth in specimens tempered at higher temperature was enhanced, while that in cold worked ones is suppressed.

Operation and maintenance experience on the fuel handling systems and storage facilities of "MONJU", 1

; ; Yamada, Takeshi; ; ; ; Kaito, Yasuaki; ; Kotaka, Yoshinori; ; et al.

PNC TN2410 96-005, 339 Pages, 1996/03

PNC-TN2410-96-005.pdf:14.53MB

Construction of the 'Monju' fuel handling systems was completed in April, 1992. From March 1991 to August 1992, pre-commissioning tests were carried out. In December 1992, all the systems of Monju were transfered to PNC, and commissioning tests and reactor physics tests, were started. For the first time, during these physics tests, the fuel handling systems were operated for one of the commissioning tests 'Loading to Criticality', without significant problems. 168 fuel sub-assemblies were loaded into the core and the first criticality was achieved on 5th April 1994. The fuel handling systems continued in operation for the 'Loading to Full Size of the Core', power distribution test and for cleaning discharged dummy sub-assemblies. To keep these fuel handling systems working somothly and satisfactorily annual maintenance has been carried out since 1992. This paper describes the operation and maintenance experience of fuel handling systems after the pre-commissioning tests and future study items for system reliability improvement.