Development of a design optimization framework for sodium-cooled fast reactors, 2; Development of optimization analysis control function

Doda, Norihiro; Nakamine, Yoshiaki*; Kuwagaki, Kazuki; Hamase, Erina; Kikuchi, Norihiro; Yoshimura, Kazuo; Matsushita, Kentaro; Tanaka, Masaaki

Keisan Kogaku Koenkai Rombunshu (CD-ROM), 28, 5 Pages, 2023/05

As a part of the development of the "Advanced Reactor Knowledge- and AI-aided Design Integration Approach through the whole plant lifecycle (ARKADIA)" to automatically optimize the life cycle of innovative nuclear reactors including fast reactors, ARKADIA-design is being developed to support the optimization of fast reactor in the conceptual design stage. ARKADIA-Design consists of three systems (Virtual plant Life System (VLS), Evaluation assistance and Application System (EAS), and Knowledge Management System (KMS)). A design optimization framework controls the connection between the three systems through the interfaces in each system. This paper reports on the development of an optimization analysis control function that performs design optimization analysis combining plant behavior analysis by VLS and optimization study by EAS.

Thermally altered subsurface material of asteroid (162173) Ryugu

Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.

Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03

https://doi.org/10.1038/s41550-020-01271-2

Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.

Observation and theory of X-ray mirages

Magnitskiy, S.*; Nagorskiy, N.*; Faenov, A.*; Pikuz, T.; Tanaka, Momoko; Ishino, Masahiko; Nishikino, Masaharu; Fukuda, Yuji; Kando, Masaki; Kawachi, Tetsuya; et al.

Nature Communications (Internet), 4, p.1936_1 - 1936_7, 2013/06

https://doi.org/10.1038/ncomms2923

Advent of plasma-based transient collisional excitation X-ray lasers allowed us to realize compact coherent X-ray sources, thus opening the way to a wide range of applications. Here we report the observation of unexpected concentric rings in the far-field beam profile at the output of a two-stage plasma-based X-ray laser developed in Japan Atomic Energy Agency, which can be considered as the first manifestation of a mirage phenomenon in X-rays. We have developed a method of solving the Maxwell-Bloch equations, which has allowed to find that the observed phenomenon is due to the emergence in the plasma-amplifier of X-ray mirage in the form of the phase matched coherent virtual point source. The obtained results bring a new insight into physical nature of amplification of X-ray radiation in laser-induced plasma amplifiers and open new opportunities for X-ray plasma diagnostics and extreme UV lithography.

Source development and novel applications of laser-driven plasma X-ray lasers in JAEA

Kawachi, Tetsuya; Hasegawa, Noboru; Nishikino, Masaharu; Ishino, Masahiko; Imazono, Takashi; Oba, Toshiyuki; Kaihori, Takeshi; Kishimoto, Maki; Ochi, Yoshihiro; Tanaka, Momoko; et al.

X-Ray Lasers 2010; Springer Proceedings in Physics, Vol.136, p.15 - 24, 2011/12

http://ci.nii.ac.jp/ncid/BB05543208

This paper reviews recent improvement in the source development of laser-driven X-ray lasers and the applications in the research fields of material science, laser processing, X-ray imaging, and radiation damage in biological cells. In the application for material science, we have firstly observed temporal correlation between the domain structures of ferro-electric substance under the Curie temperature. In the laser processing, new X-ray laser interferometer reveals us the nano-scale surface distortion of substance pumped by a femto-second optical pulse. In the X-ray diffraction image, we have taken several static images of micro-structure of samples: now we are trying to extend the objective to nano-scale dynamics using pump and probe method. In the radiation damage of biological cells, we observed double strand break in DNA using X-ray laser exposure; this results are compared with the case using incoherent several KeV X-ray exposure.

Spallative ablation of dielectrics by X-ray laser

Inogamov, N. A.*; Zhakhovsky, V. V.*; Faenov, A. Ya.*; Khokhlov, V. A.*; Shepelev, V. V.*; Skobelev, I. Y.*; Kato, Yoshiaki*; Tanaka, Momoko; Pikuz, T. A.*; Kishimoto, Maki; et al.

Applied Physics A, 101(1), p.87 - 96, 2010/10

https://doi.org/10.1007/s00339-010-5764-3

Evaluation of stress and strain using synchrotron radiation

Tanaka, Keisuke*; Suzuki, Kenji*; Akiniwa, Yoshiaki*; Shobu, Takahisa

Hoshako Ni Yoru Oryoku To Hizumi No Hyoka, 238 Pages, 2009/10

no abstracts in English

Low-threshold ablation of dielectrics irradiated by picosecond soft X-ray laser pulses

Faenov, A. Y.; Inogamov, N. A.*; Zhakhovskii, V. V.*; Khokhlov, V. A.*; Nishihara, Katsunobu*; Kato, Yoshiaki*; Tanaka, Momoko; Pikuz, T. A.*; Kishimoto, Maki; Ishino, Masahiko; et al.

Applied Physics Letters, 94(23), p.231107_1 - 231107_3, 2009/06

https://doi.org/10.1063/1.3152290

Direct measurement of the temporal profile of the amplification gain of the transient collisional excitation neonlike manganese X-ray laser medium

Hasegawa, Noboru; Kawachi, Tetsuya; Sasaki, Akira; Kishimoto, Maki; Sukegawa, Kota; Tanaka, Momoko; Tai, R. Z.*; Ochi, Yoshihiro; Nishikino, Masaharu; Nagashima, Keisuke; et al.

Physical Review A, 76(4), p.043805_1 - 043805_5, 2007/10

https://doi.org/10.1103/PhysRevA.76.043805

We firstly demonstrated the measurement of temporal profile of the amplification gain of the transient collisional excitation (TCE) X-ray laser with the solid target by use of X-ray diagnostic beam injection technique. In this experiment, higher-order harmonic light at a wavelength of 26.9 nm was injected into the neon-like manganese plasma as X-ray laser medium, and the amplified signal was observed. The obtained buildup time of the amplification gain was 23 ps measured from the time of the main pumping laser pulse, and the lifetime of the amplification gain was 27 ps. This result was in good agreement with the theoretical simulation by using an atomic kinetics code.

Research and development of minor actinide-containing fuel and target in a future integrated closed cycle system

Osaka, Masahiko; Serizawa, Hiroyuki; Kato, Masato; Nakajima, Kunihisa; Tachi, Yoshiaki; Kitamura, Ryoichi; Miwa, Shuhei; Iwai, Takashi; Tanaka, Kenya; Inoue, Masaki; et al.

Journal of Nuclear Science and Technology, 44(3), p.309 - 316, 2007/03

https://doi.org/10.3327/jnst.44.309

no abstracts in English

Application of strain scanning method to stress measurement of austenitic stainless steel

Shobu, Takahisa; Mizuki, Junichiro; Suzuki, Kenji*; Suzuki, Hiroshi; Akiniwa, Yoshiaki; Tanaka, Keisuke*

Zairyo, 55(7), p.647 - 653, 2006/07

https://doi.org/10.2472/jsms.55.647

no abstracts in English