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Tanaka, Shingo*; Yokota, Hideharu; Ono, Hirokazu; Nakayama, Masashi; Fujita, Tomoo; Takiya, Hiroaki*; Watanabe, Naoko*; Kozaki, Tamotsu*
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 6 Pages, 2015/05
to extreme environmentsHorikawa, Daiki*; Yamaguchi, Ayami*; Sakashita, Tetsuya; Tanaka, Daisuke*; Hamada, Nobuyuki*; Yukuhiro, Fumiko*; Kuwahara, Hirokazu*; Kunieda, Takekazu*; Watanabe, Masahiko*; Nakahara, Yuichi*; et al.
Astrobiology, 12(4), p.283 - 289, 2012/04
Times Cited Count：23 Percentile：68.44(Astronomy & Astrophysics)We examined the hatchability of hydrated and anhydrobiotic eggs of the tardigrade to hatch after ionizing irradiation (helium ions), extremely low and high temperatures, and high vacuum. Anhydrobiotic eggs (50% lethal dose; 1690 Gy) were substantially more radioresistant than hydrated ones (50% lethal dose; 509 Gy). Anhydrobiotic eggs also have a broader temperature resistance compared with hydrated ones. Over 70% of the anhydrobiotic eggs treated at high and low temperatures, but all of the hydrated eggs failed to hatch. After exposure to high vacuum conditions, the hatchability of the anhydrobiotic eggs was comparable to that of untreated control eggs.
Naito, Fujio*; Nammo, Kesao*; Tanaka, Hirokazu*; Asano, Hiroyuki; Ito, Takashi
Proceedings of 25th International Linear Accelerator Conference (LINAC 2010) (CD-ROM), p.569 - 571, 2010/09
X-ray radiation from the SDTL of J-PARC linac has been observed with the beam loss monitor by the cavity. The results show that the X-ray intensity depends not only on the RF power level of the tank but also on the RF structure of the tank. In the paper we will show the results of the investigation for the origin of the X-ray radiation from the tank.
Saito, Takumi*; Sao, Hirokazu*; Ishida, Keisuke*; Aoyagi, Noboru; Kimura, Takaumi; Nagasaki, Shinya*; Tanaka, Satoru*
Environmental Science & Technology, 44(13), p.5055 - 5060, 2010/07
Times Cited Count：33 Percentile：61.31(Engineering, Environmental)Ito, Takashi; Asano, Hiroyuki; Tanaka, Hirokazu*; Kubota, Chikashi*; Nammo, Kesao*; Naito, Fujio*
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.690 - 692, 2010/03
The J-PARC DTL and SDTL have been operated since 2006. These linacs accelerate an H
ion beam stably now. But we have ever suffered from some troubles. These are the vacuum, the cooling water and the RF trouble mainly. In this paper, these troubles that happened to the DTL and SDTL are reported.
Zhao, Y.; Tanaka, Hirokazu*; Miyamoto, Nobuyoshi*; Koizumi, Satoshi; Hashimoto, Takeji
Macromolecules, 42(5), p.1739 - 1748, 2009/04
Times Cited Count：15 Percentile：45.49(Polymer Science)Hasegawa, Kazuo; Asano, Hiroyuki; Chishiro, Etsuji; Hori, Toshihiko; Ito, Takashi; Kobayashi, Tetsuya; Kondo, Yasuhiro; Namekawa, Yuya; Oguri, Hidetomo; Okoshi, Kiyonori; et al.
Proceedings of 24th International Linear Accelerator Conference (LINAC 2008) (CD-ROM), p.55 - 57, 2009/00
The beam commissioning of the J-PARC linac started in November 2006 and 181 MeV acceleration was successfully achieved in January 2007. The linac has delivered beams to the 3 GeV Rapid Cycling Synchrotron for its commissioning, and then, the subsequent Main Ring Synchrotron and the neutron target commissioning. The linac uses a Cs-free LaB
-driven ion source and 20 units of 324 MHz klystrons. As of June 2008, the operation times are about 3,000 and 6,000 hours for the ion source and the RF source, respectively. The operating experience of the linac is described.
Tanaka, Hirokazu*; Hashimoto, Takeji; Koizumi, Satoshi; Ito, Hideaki*; Naka, Kensuke*; Chujo, Yoshiki*
Macromolecules, 41(5), p.1815 - 1824, 2008/03
Times Cited Count：8 Percentile：26.71(Polymer Science)We have investigated the self-assembly formed by palladium acetate (Pd(OAc)
) and polyamidoamine dendrimers (GN-NH) in a mixed solvent of methanol and N, N-dimethylformamide. We aim to explore effects of the generation number (GN) and concentration of the dendrimers, [GN-NH], on the self-assembly of the dendrimers (defined hereafter as "templates") and the Pd nanoparticles inside the templates in order to clarify physical factors controlling the self-assembling mechanisms. We found that the templates are formed only when [GN-NH] falls below a critical value and thereby a sufficient amount of Pd(OAc) exists as the binders between the dendrimers. Otherwise dendrimers are molecularly dispersed in solution.
Morishita, Takatoshi; Ao, Hiroyuki; Asano, Hiroyuki; Ito, Takashi; Ueno, Akira; Okawa, Tomohiro; Hasegawa, Kazuo; Ikegami, Masanori*; Naito, Fujio*; Tanaka, Hirokazu*; et al.
Proceedings of 10th International Workshop on Accelerator Alignment (IWAA 2008) (Internet), 6 Pages, 2008/02
It has been widely accepted that an accurate alignment is essential to achieve high beam quality and highly stable operation increasingly demanded in recent particle accelerators. The J-PARC linac components are finely aligned based on the precise survey network, where we have emphasized on attaining the smoothness between adjacent elements. A floor elevation of the accelerator tunnel has been periodically measured since the completion of the linac building to correct the error by the settlement. The alignment of the linac components have been finished at Sep. 2006 and the beam commissioning has been started at Nov. 2006. After a coarse adjustment of the RF phase and amplitude, nearly complete beam transmission was easily established without using steering magnet. This successful beam transport proves the validity of the alignment strategy and the accurateness of the alignment procedure.
Tanaka, Hirokazu*; Koizumi, Satoshi; Hashimoto, Takeji; Kurosaki, Kazuhiro*; Kobayashi, Shiro*
Macromolecules, 40(17), p.6304 - 6315, 2007/08
Times Cited Count：30 Percentile：65.94(Polymer Science)We have investigated the self-assembling process of cellulose artificially synthesized via enzymatic polymerization as one of general problems of non-equilibrium phenomenon and pattern formation. The chemical reaction and the self-assembling process were explored at real time and in-situ by a combined small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), ultra-SANS and ultra-SAXS method, together with wide-angle X-ray diffraction and field-emission scanning electron microscopy. The results revealed for the first time the following pieces of new evidence: (1) The enzymes (cellulase) as a catalyst aggregate themselves into associations; (2) Cellulose molecules created at each active site of enzymes associate themselves around the enzyme associations into cellulose aggregates having surface fractal dimensions Ds, increasing from 2 to 2.3 with reaction time. (3) The fractal structure formed at the end of the reaction extends over a surprisingly wide length scale ranging from 30 nm to 30 
m (3 orders of magnitude).
Mita, Kazuki*; Tanaka, Hirokazu*; Saijo, Kenji*; Takenaka, Mikihito*; Hashimoto, Takeji
Macromolecules, 40(16), p.5923 - 5933, 2007/08
Times Cited Count：41 Percentile：74.87(Polymer Science)A zone heating method, which imposes the moving temperature-gradient field on order in process of various melts in general, enabled to control a macroscopic orientation of microdomain structures in block copolymer bulk. We applied the method to a polystyrene-block-polyisoprene diblock copolymer forming hexagonally packed cylindrical domains (hex-cyl) in the absence of extermal fields. We discovered that the method creates the following special texture of hex-cyl; (1) The texture seemingly consists of volume-filled columnar grains with the grain axis parallel to the temperature gradient axis (defined as the oz axis). (2) The cylinder axis always orients perpendicular to the oz axis with a rotational angle 
of the cylinder axis around the oz axis being fixed within a grain.
Tanaka, Hirokazu*; Koizumi, Satoshi; Hashimoto, Takeji; Ito, Hideaki*; Sato, Masahide*; Naka, Kensuke*; Chujo, Yoshiki*
Macromolecules, 40(12), p.4327 - 4337, 2007/06
Times Cited Count：32 Percentile：67.79(Polymer Science)We reported the reduction process of palladium(II) acetate, Pd(OAc), and self-assembling process of the resulting palladium atoms, Pd(0)'s, into nanoparticles in the presence of the first-generation polyamidoamine dendrimer (G1-NH) in non-aqueous solution. The process was induced by mixing the following two solutions: (A) Pd(OAc) dissolved in N,N-dimethylformamide (DMF) and (B) the G1-NH dissolved in methanol, under a specific condition of 
[Pd(OAc)]/[-NH] = 3.3 where [-NH] is mole concentration of the amine groups in the dendrimer in the reaction solution. The reaction and reaction-induced self-assembling process were explored in-situ by means of a combined time-resolved method of small-angle neutron scattering and small-angle X-ray scattering. The method revealed time-evolution of a series of self-assembling processes occurring in the system.
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.
Ito, Takashi; Asano, Hiroyuki; Morishita, Takatoshi; Ao, Hiroyuki; Tanaka, Hirokazu*; Naito, Fujio*; Kato, Takao*; Takasaki, Eiichi*
Proceedings of 2007 Particle Accelerator Conference (PAC '07) (Internet), p.1517 - 1519, 2007/06
The high-power conditioning of the three DTL tanks for the J-PARC has been started in October 2006. The design rf peak-power levels for beam acceleration of the tanks are about 1.1MW (DTL1), 1.2MW (DTL2) and 1.0MW (DTL3), respectively. As a result of the conditioning, we have achieved that the rf power levels are about 1.3MW, 1.45MW and 1.23MW of which are 1.2 times the power levels of the desired one (the pulse length is 650s and the pulse repetition is 25Hz). During the linac beam commissioning, the DTLs can keep the required rf power stable now.
Hashimoto, Takeji; Tanaka, Hirokazu*; Koizumi, Satoshi; Naka, Kensuke*; Chujo, Yoshiki*
Journal of Applied Crystallography, 40(s1), p.s73 - s77, 2007/04
Times Cited Count：18 Percentile：83.29(Chemistry, Multidisciplinary)As a problem in open non-equilibrium phenomena, we present small-angle scattering studies of chemical-reaction at specific sites and reaction-induced self-assembly of the system which is induced by mixing two stable solutions of palladium (II) acetate (Pd(OAc)) in N,N-dimethylformamide and the second-generation polyamidoamine dendrimer in methanol.
observation from 10
to 2.0
using a focusing and polarized neutron small-angle scattering spectrometer, SANS-J-IIIwase, Hiroki; Koizumi, Satoshi; Suzuki, Junichi; Oku, Takayuki; Sasao, Hajime*; Tanaka, Hirokazu*; Shimizu, Hirohiko*; Hashimoto, Takeji
Journal of Applied Crystallography, 40(s1), p.s414 - s417, 2007/04
Times Cited Count：15 Percentile：80.23(Chemistry, Multidisciplinary)In order to extend an upper q-limit larger, high-angle He sub-detectors were installed on focusing and polarized neutron small-angle scattering spectrometer (SANS-J-II) at JRR-3, Tokai. Consequently, its upper q-limit was improved from 0.2 to 2. To quantitatively discriminate spin incoherent scattering from hydrogen or to perform nuclear spin polarization contrast variation, a remanent supermirror analyser is also available on the high-angle sub detector. By combining a focusing ultra-small angle scattering, realized by compound and/or magnetic lens and high resolution area detector, SANS-J-II is able to cover from 3
10
to 2 (four order of magnitude of q), which profits to investigate hierarchically ordered system, found widely in hard, soft and bio-materials.
Ito, Takashi; Asano, Hiroyuki; Morishita, Takatoshi; Yamazaki, Yoshishige; Naito, Fujio*; Takasaki, Eiichi*; Yoshino, Kazuo*; Tanaka, Hirokazu*; Kato, Takao*; Kabeya, Zenzaburo*; et al.
Proceedings of 23rd International Linear Accelerator Conference (LINAC 2006) (CD-ROM), p.782 - 784, 2007/00
Three DTL tanks and 32 SDTL tanks for the Japan Proton Accelerator Research Complex (J-PARC) were assembled at KEK site. After the assembling, the high-power conditioning of the DTL1 and 12 SDTL tanks and the beam acceleration test for the DTL1 ware carried out. And then all the DTL and SDTL tanks have to be transported form KEK to JAEA. In order to confirm the effect of the transportation to the drift tube alignment, we measured the displacement of the drift tube positions before and after the transportation by using a prototype cavity. As a result of the test, the measured displacement of the drift tubes by the transportation was less than 0.02mm which is consistent in the measurement accuracy. Based on this result, all the DTL and SDTL tanks were transported form KEK to JAEA.
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.
Suzuki, Hiroyuki; Chishiro, Etsuji; Ito, Takashi; Kobayashi, Tetsuya; Hasegawa, Kazuo; Anami, Shozo*; Yamaguchi, Seiya*; Michizono, Shinichiro*; Fang, Z.*; Naito, Fujio*; et al.
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM), p.513 - 515, 2007/00
no abstracts in English
Koizumi, Satoshi; Iwase, Hiroki; Suzuki, Junichi; Oku, Takayuki; Motokawa, Ryuhei; Sasao, Hajime*; Tanaka, Hirokazu; Yamaguchi, Daisuke; Shimizu, Hirohiko; Hashimoto, Takeji
Physica B; Condensed Matter, 385-386(2), p.1000 - 1006, 2006/11
Times Cited Count：39 Percentile：80.57(Physics, Condensed Matter)no abstracts in English
