Development of a bio-based adhesive by polymerization of Boc-protected vinyl catechol derived from caffeic acid

Tanizaki, Shiho*; Kubo, Tomohiro*; Bito, Yosuke*; Mori, Shigeki*; Aoki, Hiroyuki; Sato, Kotaro*

RSC Sustainability (Internet), 3(4), p.1714 - 1720, 2025/04

https://doi.org/10.1039/D4SU00629A

Micro-fabrication of biodegradable polymers using focused ion beam

Okubo, Satoshi*; Takahashi, Tomohiro*; Takasawa, Yuya*; Gowa, Tomoko*; Sasaki, Takashi*; Nagasawa, Naotsugu; Tamada, Masao; Oshima, Akihiro*; Tagawa, Seiichi*; Washio, Masakazu*

Journal of Photopolymer Science and Technology, 23(3), p.393 - 397, 2010/11

https://doi.org/10.2494/photopolymer.23.393

Microfabrication of biodegradable polymers such as poly(butylene succinate--adipate) (PBSA) and poly(-caprolactone) (PCL) were demonstrated using focused ion beam (FIB) with maskless direct etching. As the result, the micro structures of PBSA and PCL were obtained. The etching depth of both PBSA and PCL were increased with increasing FIB fluence, and the etching rates were estimated to be about 1.3 10 m/(ions cm) and 1.2 10 m/(ions cm), respectively. Moreover, very thin films of PBSA and PCL were made by spin-coating method. The thicknesses of the spin-coated samples were about 200 nm, and the surface roughness was less than 10 nm (RMS). The fine structures such as micro-gear of PBSA and PCL were obtained without solid debris. The line width of the fabricated structure was about 250 nm.

Extended steady-state and high-beta regimes of net-current free heliotron plasmas in the large helical device

Motojima, Osamu*; Yamada, Hiroshi*; Komori, Akio*; Oyabu, Nobuyoshi*; Kaneko, Osamu*; Kawahata, Kazuo*; Mito, Toshiyuki*; Muto, Takashi*; Ida, Katsumi*; Imagawa, Shinsaku*; et al.

Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 12 Pages, 2007/03

http://www-naweb.iaea.org/napc/physics/FEC/FEC2006/html/node31.htm#5947

The performance of net-current free Heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping/fueling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have elucidated the advantages of net-current free heliotron plasmas. In particular, an Internal Diffusion Barrier (IDB) by combination of efficient pumping of the local island divertor function and core fueling by pellet injection has realized a super dense core as high as 510m, which stimulates an attractive super dense core reactor. Achievements of a volume averaged beta of 4.5 % and a discharge duration of 54-min. with a total input energy of 1.6 GJ (490 kW in average) are also highlighted. The progress of LHD experiments in these two years is overviewed with highlighting IDB, high and long pulse.

Magnetic field measurements, 3D field calculation and heat measurements of a prototype thick septum magnet for 3 GeV rapid cycling synchrotron of J-PARC

Watanabe, Masao; Irie, Yoshiro; Kamiya, Junichiro; Shimada, Taihei; Takayanagi, Tomohiro; Suzuki, Hiromitsu; Watanabe, Yasuhiro; Kawakubo, Toshimichi*

IEEE Transactions on Applied Superconductivity, 16(2), p.1354 - 1357, 2006/06

https://doi.org/10.1109/TASC.2005.864317

Septum magnets used in the injection and extraction section of the 3 GeV rapid cycling synchrotron of the J-PARC require large aperture for low-loss operations of high intensity beam, protection against the high radiation and the high durability to avoid the maintenance after the high activation. A prototype septum magnet was constructed. Magnetic fields in the gap of the core and leakage field outside of the magnetic shield were measured by a Hall device probe. The experimental results were compared with the 3D calculation by TOSCA. The leakage field of the measurements is larger than the one of the model. After we made a more detailed model, it cleared that many bolt holes which fasten a return yoke narrow the effective sectional area and thus reduce the permeability at the return yoke, making the leakage field larger. Because the thickness of the return yoke is not sufficient, magnetic flux density approaches saturation easily. Moreover, we discuss about the results of heat measurements of the magnet and efficiency of water cooling.

Design of the injection bump system of the 3-GeV RCS in J-PARC

Takayanagi, Tomohiro; Kamiya, Junichiro; Watanabe, Masao; Yamazaki, Yoshishige; Irie, Yoshiro; Kishiro, Junichi; Sakai, Izumi*; Kawakubo, Toshimichi*

IEEE Transactions on Applied Superconductivity, 16(2), p.1358 - 1361, 2006/06

https://doi.org/10.1109/TASC.2005.864361

The injection bump system of the 3-GeV RCS in J-PARC consists of the pulse bending magnets for the injection bump orbit, which are four horizontal bending magnets (shift bump), four horizontal painting magnets (h-paint bump), and two vertical painting magnets (v-paint bump). In this paper, the design of the magnets and power supply of the injection bump system are reported.

The Extraction kicker system of the RCS in J-PARC

Kamiya, Junichiro; Takayanagi, Tomohiro; Kawakubo, Toshimichi*; Murasugi, Shigeru*; Nakamura, Eiji*

Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.1009 - 1011, 2005/00

The kicker magnets are installed in the vacuum chamber at the extraction section of the RCS (Rapid Cycling Synchrotron) in J-PARC (Japan Proton Accelerator Research Complex) facility. They kick the 3GeV proton beam to the extraction septum magnets followed by a downstream beam transport line. The RCS is designed to achieve the 1MW beam power with minimum loss. Therefore, the kicker is required to have a wide aperture, UHV (ultra-high vacuum) in its chamber, and uniformity of magnetic field. The wide aperture requires large exciting current and the use environment of the thyratron is very tough. Therefore aging run was found out to be needed. And the uniformity of the magnetic field was improved by changing length of the conductors. In order to achieve the UHV, we succeeded in reducing outgas from components of the magnet. In this paper, we will introduce the specification of the extraction kicker system in the RCS, and report countermeasure against the technical challenge described above.

Feasibility Study on Commercialization of Fast Breeder Reactor Cycle Systems Interim Report of Phase II; Technical Study Report for Reactor Plant Systems

Konomura, Mamoru; Ogawa, Takashi; Okano, Yasushi; Yamaguchi, Hiroyuki; Murakami, Tsutomu; Takaki, Naoyuki; Nishiguchi, Youhei; Sugino, Kazuteru; Naganuma, Masayuki; Hishida, Masahiko; et al.

JNC TN9400 2004-035, 2071 Pages, 2004/06

JNC-TN9400-2004-035.pdf:76.42MB

The attractive concepts for Sodium-, lead-bismuth-, helium- and water-cooled FBRs have been created through using typical plant features and employing advanced technologies. Efforts on evaluating technological prospects of feasibility have been paid for these concepts. Also, it was comfirmed if these concepts satisfy design requierments of capability and performance presumed in the feasibilty study on commertialization of Fast Breeder Reactor Systems. As results, it was concluded that the selection of sodium-cooled reactor was most rational for practical use of FBR technologies in 2015.

Enhancement of IR-light emission from -FeSi nanocrystals by Cu doping

Hirata, Tomoaki*; Kagawa, Seiya*; Nagatsuyu, Tomohiro*; Shibahara, Kohei*; Iwamoto, Ryotaro*; Kawakubo, Yuki*; Noguchi, Masaya*; Mizuki, Tatsuya*; Narumi, Kazumasa; Sakai, Seiji; et al.

no journal, , 

no abstracts in English

Feasible study for the production of At-211 using Liquid Bismuth Target System

Watanabe, Shigeki*; Kondo, Hiroo*; Koka, Masashi*; Takai, Toshihide; Okubo, Nariaki; Furukawa, Tomohiro; Ishioka, Noriko*

no journal, , 

Astatine-211, one of the promising alpha-emitting radionuclides for the targeted alpha therapy, is mainly produced via the Bi(alpha, 2n)At reaction. High beam current will be required to produce enough radioactivity on the order of GBq to ship to multiple hospitals for clinical applications. However, melting of target Bi induced by alpha-beam irradiation occurs and it is difficult with even low beam current due to its low melting point. We are thus developing the "Liquid Bismuth Target System" by incorporating liquid metal technologies used for such as fast reactors and fusion reactors, and we have performed alpha-beam irradiation to a prototype system as a feasible study. Produced radioactivity of At was estimated to be 367 MBq, which was identical to that estimated from produced radioactivity when using a solid Bi target under the same condition.