JOPSS - Search Results

Journal Articles

Deformation-induced martensitic transformation at tensile and compressive deformations of bainitic steels with different carbon contents

Ueji, Rintaro*; Gong, W.; Harjo, S.; Kawasaki, Takuro; Shibata, Akinobu*; Kimura, Yuji*; Inoue, Tadanobu*; Tsuchida, Noriyuki*

ISIJ International, 64(2), p.459 - 465, 2024/01

https://doi.org/10.2355/isijinternational.ISIJINT-2023-253

Times Cited Count：0 Percentile：0.00(Metallurgy & Metallurgical Engineering)

Journal Articles

In situ neutron diffraction analysis of microstructural evolution-dependent stress response in austenitic stainless steel under cyclic plastic deformation

Kumagai, Masayoshi*; Kuroda, Masatoshi*; Matsuno, Takashi*; Harjo, S.; Akita, Koichi*

Materials & Design, 221, p.110965_1 - 110965_8, 2022/09

https://doi.org/10.1016/j.matdes.2022.110965

Times Cited Count：5 Percentile：40.83(Materials Science, Multidisciplinary)

JAEA Reports

Effects of temperature history during cooling process on cladding ductility reduction under lost of coolant accident conditions

Udagawa, Yutaka; Nagase, Fumihisa; Fuketa, Toyoshi

JAERI-Research 2005-020, 40 Pages, 2005/09

JAERI-Research-2005-020.pdf:4.63MB

In order to investigate effects of quenching temperature and cooling rate before quench on cladding ductility reduction under LOCA conditions, samples cut from non-irradiated 1717-type Zircaloy-4 cladding tubes for PWRs were oxidized in steam at 1373 and 1473 K, cooled at 2 to 7 K/s, and quenched at 1073 to 1373 K. The quenched samples were subjected to ring compression test, microstructure observation, and Vickers hardness test. Quenching temperature decrease obviously increased area fraction of phase in the radial cross section of the cladding, and reduced cladding ductility. Slow-cooling rate decrease increased unit size and hardness of precipitated phase, while phase area fraction and cladding ductility were not significantly changed. phase is harder than the surrounding region in the metallic layer and has higher oxygen content, indicating its low ductility. Consequently, increase in the area fraction in the cladding is a main cause of the reduction in cladding ductility with decrease in the quenching temperature.

Journal Articles

Measurement of emittance for electron bunches compressed by velocity bunching via double-slit-scan method

Iijima, Hokuto; Hajima, Ryoichi; Uesaka, Mitsuru*; Sakumi, Akira*; Sakamoto, Fumito*; Ueda, Toru*

Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan, p.501 - 503, 2005/07

We report the availability of velocity bunching in an energy recovery linac (ERL) by a numerical analysis, and the plan of precise measurement of bunching emittance via a double-slit-scan method. The simulation performed for eight TESLA-type cavities reveals successful bunch compression from 3.2 ps to 0.17 ps. Since the residual energy spread after velocity bunching is considerably smaller than the correlated energy spread required for magnetic compression through a recirculation loop, velocity bunching is useful to realized short-pulse and high-brightness X-rays by ERL. The emittance of velocity bunching was calculated to be 1.5 mm.mrad for the bunch charge of 77pC without the emittance compensation by an external solenoid field. Although the emittance growth due to the space-charge effect was small in the simulation, it is necessary to evaluate the emittance-growth mechanism under velocity bunching. Therefore, the emittance measurement via double-slit-scan method is carrying out in the UTNL-18L.

JAEA Reports

An Irradiation experiment for qualification of insulating coating

Nakamichi, Masaru*; Kawamura, Hiroshi

JAERI-Research 2005-015, 35 Pages, 2005/06

JAERI-Research-2005-015.pdf:6.48MB

no abstracts in English

Journal Articles

Experimental verification of velocity bunching via shot-by-shot measurement at S-band photoinjector and linac

Iijima, Hokuto; Uesaka, Mitsuru*; Sakamoto, Fumito*; Ueda, Toru*; Kumagai, Noritaka*; Serafini, L.*

Japanese Journal of Applied Physics, Part 1, 44(7A), p.5249 - 5253, 2005/01

https://doi.org/10.1143/JJAP.44.5249

Times Cited Count：8 Percentile：31.81(Physics, Applied)

We represent an experimental verification of a bunch compression method named "velocity bunching". The velocity bunching based on the rectilinear compression uses a traveling wave accelerating tube as a compressor. The experiment was performed by an S-band photoinjector and a linac at Nuclear Engineering Research Laboratory, University of Tokyo. The shot-by-shot bunch length was measured to be 0.5 0.1 ps (rms) in average by the femtosecond streak camera for a bunch charge of 1 nC. The experimental result is in good agreement with PARMELA simulations.

Journal Articles

Aging deterioration test of seismic isolation applied to fusion experimental reactor

Takeda, Nobukazu; Nakahira, Masataka; Kakudate, Satoshi; Takahashi, Hiroyuki*; Shibanuma, Kiyoshi; Yabana, Shuichi*; Matsuda, Akihiro*

Proceedings of 9th World Seminar on Seismic Isolation, Energy Dissipation and Active Vibration Control of Structures (CD-ROM), p.299 - 306, 2005/00

For the ITER, a fusion experimental reactor, it is planned to use rubber bearings in order to enhance the reliability of integrity with a sufficient margin even for the earthquakes beyond the design basis earthquake. In application for nuclear plants, the vertical compression of the isolator is 25 MPa and there is no experience for such a high compression as 10 MPa to be used for the ITER. Therefore, there is not enough design data of the rubber bearings with high compression, and thus a detailed estimation of performance is necessary. As a result of the endurance test after aging, it was validated that the bearing can be applied safely until 400th cycle even after 40 years of aging. On the other hand, the residual deformation was found at the 246th cycle. This means that the residual deformation can be observed enough earlier than the change of the macroscopic mechanical parameter such as stiffness. Therefore, it is possible to prevent break of the bearing during operation by sensing a sign of break with a periodical visual inspection.

JAEA Reports

Pumping characteristics of roots blower pumps for light element gases

Hiroki, Seiji; Abe, Tetsuya; Tanzawa, Sadamitsu; Nakamura, Junichi*; Obayashi, Tetsuro*

JAERI-Tech 2002-056, 11 Pages, 2002/07

JAERI-Tech-2002-056.pdf:0.79MB

no abstracts in English

JAEA Reports

Characteristic evaluation of high compression seismic isolator for International Thermonuclear Experimental Reactor (ITER); Verification test of sub-scaled rubber bearings (Contract research)

Takahashi, Hiroyuki*; Nakahira, Masataka; Yabana, Shuichi*; Matsuda, Akihiro*; Otori, Yasuki*

JAERI-Tech 2001-064, 111 Pages, 2001/11

JAERI-Tech-2001-064.pdf:8.96MB

no abstracts in English

Journal Articles

Bright electron multi-bunch production for the high power JAERI-FEL oscillator

Nishimori, Nobuyuki; Hajima, Ryoichi; Nagai, Ryoji; Shizuma, Toshiyuki; Sawamura, Masaru; Kikuzawa, Nobuhiro; Minehara, Eisuke

Proceedings of 13th Symposium on Accelerator Science and Technology, p.458 - 460, 2001/00

Stable and bright electron multi-bunches at 16.5 MeV with a long macro-pulse duration over 0.4 ms, which consists of 4,000 micro-bunches, have been produced at the Japan Atomic Energy Research Institute (JAERI) superconducting linac driven Free-Electron Laser (FEL) facility. The bunch charge is 0.5 nC with peak current higher than 100 A. The bright electron bunch was generated using a RF compression made in two stages in the injector system, and directly led to a quasi-CW kilowatt lasing. In this paper, we describe the bunching system and electron beam performances in JAERI-FEL.

Journal Articles