Rabi-oscillation spectroscopy of the hyperfine structure of muonium atoms

Nishimura, Shoichiro*; Torii, Hiroyuki*; Fukao, Yoshinori*; Ito, Takashi; Iwasaki, Masahiko*; Kanda, Sotaro*; Kawagoe, Kiyotomo*; Kawall, D.*; Kawamura, Naritoshi*; Kurosawa, Noriyuki*; et al.

Physical Review A, 104(2), p.L020801_1 - L020801_6, 2021/08

https://doi.org/10.1103/PhysRevA.104.L020801

Study on oxidation model for Zircalloy-2 cladding in SFP accident condition

Nemoto, Yoshiyuki; Kaji, Yoshiyuki; Onizawa, Takashi*; Kanazawa, Toru*; Nakashima, Kazuo*; Tojo, Masayuki*

Proceedings of Annual Congress of the European Federation of Corrosion (EUROCORR 2018) (USB Flash Drive), 8 Pages, 2018/09

The authors proposed oxidation models based on oxidation data which previously obtained in high temperature oxidation tests on small sample of Zircalloy-2 (Zry2) cladding in dry air and in air/steam mixture environment. The oxidation models were implemented in computational fluid dynamics (CFD) code to analyse oxidation behavior of long cladding sample in hypothetical spent fuel pool (SFP) accident conditions. The oxidation tests were conducted using Zry2 cladding sample 500 mm in length. The oxide layer growth in dry air was well reproduced in the calculation using the oxidation model, meanwhile which in air/steam mixture was overestimated atmosphere composition change anticipated in the spent fuel rack during the accident, and its influence on the oxidation behaviour of the cladding were discussed in consideration of the oxidation model improvement.

Optical designs of reflection and refraction collection optics for a JT-60SA core Thomson scattering system

Tojo, Hiroshi; Hatae, Takaki; Hamano, Takashi; Sakuma, Takeshi; Itami, Kiyoshi

Review of Scientific Instruments, 84(9), p.093506_1 - 093506_8, 2013/09

https://doi.org/10.1063/1.4821248

First measurement of electron temperature from signal ratios in a double-pass Thomson scattering system

Tojo, Hiroshi; Ejiri, Akira*; Hiratsuka, Junichi*; Yamaguchi, Takashi*; Takase, Yuichi*; Itami, Kiyoshi; Hatae, Takaki

Review of Scientific Instruments, 83(2), p.023507_1 - 023507_4, 2012/02

https://doi.org/10.1063/1.3685612

Surface study of organopalladium molecules on S-terminated GaAs

Konishi, Tomoya*; Nishiwaki, Nagatoshi*; Tojo, Takashi*; Ishikawa, Takuma*; Teraoka, Teruki*; Ueta, Yukiko*; Kihara, Yoshifumi*; Moritoki, Hideji*; Tono, Tatsuo*; Musashi, Mio*; et al.

Physica Status Solidi (C), 8(2), p.405 - 407, 2011/02

https://doi.org/10.1002/pssc.201000436

Conceptual design of polychromator for Thomson scattering system in JT-60SA

Tojo, Hiroshi; Hatae, Takaki; Sakuma, Takeshi; Hamano, Takashi; Itami, Kiyoshi

Journal of Plasma and Fusion Research SERIES, Vol.9, p.288 - 293, 2010/08

http://www.jspf.or.jp/JPFRS/PDF/Vol9/jpfrs2010_09-288.pdf

Significant loss in transmissivity of the used fiber after the 18 years operations in JT-60U are found. Therefore, an optimization of the filter's configuration of the polychromator in Thomson scattering system for the high performance plasmas in JT-60SA is an essential task. Especially, loss in optical components induced by radiation from neutrons and -ray should be examined. In this paper, an optimization of the filter configuration in the polychromator is executed and expected error degradation due to the radiation damages in the measurements are also estimated with a comparison between used fibers in JT-60U and radiation resistance fibers. In 10 keV, the time evolution of the averaged relative errors for the radiation resistance fibers increase from 35% by . However, for the used fibers in JT-60U, the errors are 78% and they reaches more than 10% in some high conditions, suggesting some difficulties in the measurements.

Design of collection optics and port-plug for Thomson scattering system in JT-60SA

Tojo, Hiroshi; Hatae, Takaki; Sakuma, Takeshi; Hamano, Takashi; Shinohara, Koji; Itami, Kiyoshi; Aida, Yoshiaki*; Suito, Satoshi*; Fujie, Daijiro*

no journal, , 

Conceptual designs of the collection optics for JT-60SA Thomson scattering have been done. Adapting four glass materials of the lenses used for the collection optics enables to correct the chromatic aberrations with good resolution ( 1 mm). The whole radial profile can be measured using three designed collection optics in Port-P1, P2 and P5. The collection optics will be installed in port-plugs accessing from the cryostat to vacuum vessel. In a disruption with a decrease of the plasma current by a time scale of 5 MA/8 ms, the eddy current (0.1 MA/m) is strongly generated in the area of 500 mm from the edge of the port-plug with the thickness of 30 mm. Even if the thickness is reduced to 20 mm decreasing the current in the area, the maximum principal stress is still under the limit value for the design.

Recent development of the plasma diagnostics for JT-60SA

Itami, Kiyoshi; Shinohara, Koji; Hatae, Takaki; Kamiya, Kensaku; Fukumoto, Masakatsu; Nakano, Tomohide; Yoshida, Maiko; Tojo, Hiroshi; Arakawa, Hiroyuki; Kokusen, Shigeharu; et al.

no journal, , 

Development of a Thomson scattering diagnostic design for JT-60SA

Tojo, Hiroshi; Hatae, Takaki; Sakuma, Takeshi; Hamano, Takashi; Itami, Kiyoshi

no journal, , 

Progress of diagnostics development in JAEA

Kawano, Yasunori; Sugie, Tatsuo; Ogawa, Hiroaki; Tojo, Hiroshi; Yatsuka, Eiichi; Imazawa, Ryota; Hatae, Takaki; Hamano, Takashi; Sakuma, Takeshi; Takeuchi, Masaki; et al.

no journal, , 

no abstracts in English