Intruder configurations in Ne at the transition into the island of inversion; Detailed structure study of Ne

Wang, H.*; Yasuda, Masahiro*; Kondo, Yosuke*; Nakamura, Takashi*; Tostevin, J. A.*; Ogata, Kazuyuki*; Otsuka, Takaharu*; Poves, A.*; Shimizu, Noritaka*; Yoshida, Kazuki; et al.

Physics Letters B, 843, p.138038_1 - 138038_9, 2023/08

https://doi.org/10.1016/j.physletb.2023.138038

Detailed -ray spectroscopy of the exotic neon isotope Ne has been performed using the one-neutron removal reaction from Ne. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder p-wave strength providing evidence of the breakdown of the N = 20 and N = 28 shell gaps. Only a weak, possible f-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large p-wave and small f-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.

Evaluation of mechanical properties and nano-meso structures of 9-11%Cr ODS steels

Tanno, Takashi; Otsuka, Satoshi; Yano, Yasuhide; Kaito, Takeji; Oba, Yojiro*; Onuma, Masato*; Koyama, Shinichi; Tanaka, Kenya

Journal of Nuclear Materials, 440(1-3), p.568 - 574, 2013/09

https://doi.org/10.1016/j.jnucmat.2013.04.006

This study carried out mechanical tests and microstructure characterizations of several 9Cr and 11Cr-ODS tempered martensitic steels, and discussed the appropriate chemical composition range of 11Cr-ODS tempered martensitic steel from the viewpoint of high-temperature strength improvement. It was shown that the residual -ferrite fraction in 11Cr-ODS steel was successfully controlled to the same level as the 9Cr-ODS steel by selecting the matrix chemical compositions on the basis of the multi-component phase diagram. The tensile strength decreased with decreasing W content from 2.0 to 1.4 wt%. On the other hand, creep strength at 973 K did not degrade by the decreasing W content. Both tensile strength and creep strength increased with increasing population of the nano-sized oxide particles. Small angle X-ray scattering analysis revealed that titanium and excess oxygen contents were key parameters in order to improve the dispersion condition of nano-sized oxide particles.

Training report of the FBR cycle training facility in 2004FY

Watanabe, Tomoo; Ozawa, Kazumasa; Otsuka, Jiro; Sasaki, Kazuichi; Sawada, Makoto

JNC TN4440 2005-001, 40 Pages, 2005/07

JNC-TN4440-2005-001.pdf:1.85MB

no abstracts in English

Training report of the FBR cycle training facility in 2004FY

Watanabe, Tomoo; Ozawa, Kazumasa; Otsuka, Jiro; SASAKI, Kazuhito; Sawada, Makoto

JNC TN4410 2004-003, 20 Pages, 2004/07

JNC-TN4410-2004-003.pdf:0.66MB

The FBR cycle training facility consists of sodium handling training facility and maintenance training facility, and is being contributed to train for the operators and maintenance workers of the prototype fast breeder reactor "Monju". So far, some training courses have been added to the both training courses of sodium handling technologies maintenance technologies in every year in order to carry out be significant training for preparation of Monju restarting. As encouragement of the sodium handling technology training in 2003FY, the sodium heat transfer basic course was equipped as the 9th sodium handling training course with the aims of learning basic principal technology regarding sodium heat transfer. While, for the maintenance training course, a named "Monju Systems Learning Training Course", which aims to learn necessary knowledge as the engineers related Monju development, was provided newly in this year as an improvement concerned the maintenance course. In 2003FY, nine sodium handling technology training courses were carried out total 33 times and 235 trainees took part in those training courses. Also, nine training courses concerning the maintenance technology held 15 times and total 113 trainees participated. On the other hand, the 4th special lecture related sodium technology by France sodium school instructor was held on Mar. 15-17 and 34 trainees participated. Consequently, a cumulative trainees since October in 2000 opened the FBR cycle training facility reached to 1,236 so for.

None

Otsuka, Jiro; Kawanishi, Tomotake*; Koyagishi, Naoki; Sasaki, Kazuichi; Sawada, Makoto

JNC TN4410 2003-009, 31 Pages, 2003/12

JNC-TN4410-2003-009.pdf:0.75MB

None

Creep strength and nano-macro structure of high-Cr martensitic steel

Tanno, Takashi; Otsuka, Satoshi; Kaito, Takeji; Yano, Yasuhide; Koyama, Shinichi; Tanaka, Kenya; Oba, Yojiro*; Onuma, Masato*

no journal, , 

The 9Cr-ODS martensitic steel is under development as first candidate material for fast reactor long life fuel cladding. It should have high temperature strength, irradiation resistance and productibility. The 11Cr-ODS steels with additional corrosion resistance by Cr enrichment are also under development. And the evaluation of their applicability for cladding material is in progress. Trial manufacture, creep test and nano/macro structure evaluation of several ODS steels were carried out to modify the chemical composition and manufacturing process of the 11Cr-ODS steel. Uni-axial creep strength of manufactured 11Cr-ODS steels were equal to or higher than that of 9Cr-ODS steel. The strength of 11Cr-ODS steels with 0.3wt% Ti was slightly higher than that with 0.2wt% Ti. The size and number density of dispersed-oxide depended on the amount of added Ti and extra-oxygen.