Dissolved radiocaesium in seawater off the coast of Fukushima during 2013-2015

Fukuda, Miho*; Aono, Tatsuo*; Yamazaki, Shinnosuke*; Nishikawa, Jun*; Otosaka, Shigeyoshi; Ishimaru, Takashi*; Kanda, Jota*

Journal of Radioanalytical and Nuclear Chemistry, 311(2), p.1479 - 1484, 2017/02

https://doi.org/10.1007/s10967-016-5009-9

In order to investigate processes affecting distribution of radiocaesium in seawater in the adjacent region of Fukushima Daiichi Nuclear Power Plant (FDNPP), relationships between Cs activity in seawater and physical properties of seawater (salinity, temperature, and potential density) were observed in seven stations within 10 km radius from the FDNPP. As a whole, Cs concentrations in seawater were higher in the vicinity of the FDNPP, and were negatively correlated with potential density. From these results, it can be considered that river water discharge or export of seawater from the FDNPP's harbor has affected the higher activity levels of Cs in seawater. It was also observed that the Cs-elevated seawater can be advected to the 2050 m depths.

Development of a turbo-molecular pump with a magnetic shield function

Ogiwara, Norio; Yanagibashi, Toru; Hikichi, Yusuke; Nishikawa, Masaaki; Kamiya, Junichiro; Wada, Kaoru*

Vacuum, 98, p.18 - 21, 2013/12

https://doi.org/10.1016/j.vacuum.2012.09.024

Reduction of outgassing from the ferrite cores in the kicker magnet of J-PARC 3-GeV rapid cycling synchrotron

Ogiwara, Norio; Suganuma, Kazuaki; Hikichi, Yusuke; Nishikawa, Masaaki; Yanagibashi, Toru; Kamiya, Junichiro; Kinsho, Michikazu

Journal of the Vacuum Society of Japan, 56(5), p.159 - 162, 2013/05

https://doi.org/10.3131/jvsj2.56.159

Status of the vacuum system in J-PARC RCS

Kamiya, Junichiro; Ogiwara, Norio; Nishikawa, Masaaki; Hikichi, Yusuke; Yanagibashi, Toru; Kinsho, Michikazu

Proceedings of 3rd International Particle Accelerator Conference (IPAC '12) (Internet), p.2522 - 2524, 2012/05

http://accelconf.web.cern.ch/accelconf/IPAC2012/papers/weppd013.pdf

In the vacuum system of J-PARC Rapid cycling synchrotron (RCS), we use beam pipes and bellows whose materials are vacuum fired at 700850 C in order to eliminate atoms in their bulk who are origin of outgassing. Until now, beam power has been increased up to 300 kW. Pressure in synchrotron beam line increased when the high power beam was accelerated. However, increment of pressure has reduced during the continuous beam operation. It is because the molecules, which adsorb on surface of the wall of the vacuum chambers, desorb by an ion bombardment and a heat generation due to an eddy current. Because the atoms in the bulk is eliminated, desorption of the molecules, which adsorb on the surface, means the reduction of the outgassing from the wall. In this presentation, we will report the past situation of the vacuum system during the beam operation. In addition, we also show the status after the Great East Japan Earthquake.

Development of an in-situ bake-out method for outgassing reduction of kicker ferrite cores

Kamiya, Junichiro; Ogiwara, Norio; Nishikawa, Masaaki; Hikichi, Yusuke; Yanagibashi, Toru; Suganuma, Kazuaki

Journal of the Vacuum Society of Japan, 55(4), p.156 - 159, 2012/04

https://doi.org/10.3131/jvsj2.55.156

It is usually difficult to reduce outgassing of a large structure inside a vacuum chamber by baking the whole chamber, which causes the large extension of the chamber and needs a lot of heater power. The solution is to rise the temperature of structure object without heating the vacuum chamber. This means to install heat source inside the chamber and increase the heat quantity to the object by inserting the heat shield between the object and the chamber. In the particle accelerator field, there are a lot of such requirements for reducing outgassing of structures inside vacuum chambers. One example is a kicker magnet, which is installed in a vacuum chamber and consists mainly of ferrite cores and aluminum electric plates. We applied the above method to the outgassing reduction of the kicker. In this article, we show outline of this in-situ bake-out method, the effects of the heat shield on the heat quantity and the result of the outgassing reduction.

Development of micromachining technology in ion microbeam system at TIARA, JAEA

Kamiya, Tomihiro; Nishikawa, Hiroyuki*; Sato, Takahiro; Haga, Junji; Oikawa, Masakazu*; Ishii, Yasuyuki; Okubo, Takeru; Uchiya, Naoyuki; Furuta, Yusuke*

Applied Radiation and Isotopes, 67(3), p.488 - 491, 2009/03

https://doi.org/10.1016/j.apradiso.2008.06.021

Development of a mask-less ion beam lithography technique for fabricating micro- or nano-meter sized structures has been started at the microbeam systems in the ion accelerator facility of JAEA Takasaki (TIARA) in collaboration with Shibaura Institute of Technology. In order to obtain a high precision measure for microbeam size estimation and lens system optimization, or for improvement of spatial resolution down to 100 nm level, we applied this lithography technique itself combined with the electroplating process to make a Ni relief pattern as an optimum resolution standard to be used in secondary electron imaging. In this work, using this standard, the smallest beam size could be obtained. This paper also discuses on the scattering of ions in the materials influenced to the resolution using a Monte Carlo simulation code.

The H-Invitational Database (H-InvDB); A Comprehensive annotation resource for human genes and transcripts

Yamasaki, Chisato*; Murakami, Katsuhiko*; Fujii, Yasuyuki*; Sato, Yoshiharu*; Harada, Erimi*; Takeda, Junichi*; Taniya, Takayuki*; Sakate, Ryuichi*; Kikugawa, Shingo*; Shimada, Makoto*; et al.

Nucleic Acids Research, 36(Database), p.D793 - D799, 2008/01

https://doi.org/10.1093/nar/gkm999

Here we report the new features and improvements in our latest release of the H-Invitational Database, a comprehensive annotation resource for human genes and transcripts. H-InvDB, originally developed as an integrated database of the human transcriptome based on extensive annotation of large sets of fulllength cDNA (FLcDNA) clones, now provides annotation for 120 558 human mRNAs extracted from the International Nucleotide Sequence Databases (INSD), in addition to 54 978 human FLcDNAs, in the latest release H-InvDB. We mapped those human transcripts onto the human genome sequences (NCBI build 36.1) and determined 34 699 human gene clusters, which could define 34 057 protein-coding and 642 non-protein-coding loci; 858 transcribed loci overlapped with predicted pseudogenes.

Anisotropy of resonant inelastic X-ray scattering at the edge of Si; Theoretical analysis

Nishikawa, Yunori; Usuda, Manabu; Igarashi, Junichi*

Journal of the Physical Society of Japan, 73(11), p.3171 - 3176, 2004/11

https://doi.org/10.1143/JPSJ.73.3171

no abstracts in English

Micro-machining of resist on silicon by proton beam writing

Uchiya, Naoyuki*; Harada, Takuya*; Nishikawa, Hiroyuki*; Haga, Junji; Sakai, Takuro; Sato, Takahiro; Ishii, Yasuyuki; Kamiya, Tomihiro

no journal, , 

no abstracts in English

Production of 3-D resit structures on silicon plates by a proton beam writing technique

Furuta, Yusuke*; Uchiya, Naoyuki*; Nishikawa, Hiroyuki*; Haga, Junji; Oikawa, Masakazu*; Sato, Takahiro; Ishii, Yasuyuki; Kamiya, Tomihiro

no journal, , 

no abstracts in English