Study of annealing effect on crystal and local structures of doped zirconia using multi probe

Ito, Takanori*; Mori, Masashi*; Inukai, Manabu*; Nitani, Hiroaki*; Yamamoto, Takashi*; Miyanaga, Takashi*; Igawa, Naoki; Kitamura, Naoto*; Ishida, Naoya*; Idemoto, Yasushi*

Photon Factory News, 33(1), p.18 - 24, 2015/05

http://pfwww.kek.jp/publications/pfnews/33_1/saikin1.pdf

The effect of the annealing on the crystal and local structures of doped zirconia was investigated by multi-probe technique using synchrotron X-ray and neutron diffraction, and first principles calculation. It was revealed that the annealing process enhances the periodic distortion of some zirconia compounds by Rietveld/ maximum entropy methods applied to the SR-X-ray and neutron diffractions. In addition, the combined X-ray absorption spectroscopy and first-principles calculations results showed the ZrO polyhedra in zirconia were distorted by the annealing. Those results indicate that the degradation of oxide ionic conductivity by the annealing was related to the periodic distortion in zirconia.

Evaluation of irradiation behavior on oxide dispersion strengthened (ODS) steel claddings irradiated in Joyo/CMIR-6

Yano, Yasuhide; Otsuka, Satoshi; Yamashita, Shinichiro; Ogawa, Ryuichiro; Sekine, Manabu; Endo, Toshiaki; Yamagata, Ichiro; Sekio, Yoshihiro; Tanno, Takashi; Uwaba, Tomoyuki; et al.

JAEA-Research 2013-030, 57 Pages, 2013/11

JAEA-Research-2013-030.pdf:48.2MB

It is necessary to develop the fast reactor core materials, which can achieve high-burnup operation improving safety and economical performance. Ferritic steels are expected to be good candidate core materials to achieve this objective because of their excellent void swelling resistance. Therefore, oxide dispersion strengthened (ODS) ferritic steel and 11Cr-ferritic/martensitic steel (PNC-FMS) have been respectively developed for cladding and wrapper tube materials in Japan Atomic Energy Agency. In this study, the effects of fast neutron irradiation on mechanical properties and microstructure of 9Cr-and 12Cr-ODS steel claddings for fast reactor were investigated. Specimens were irradiated in the experimental fast reactor Joyo using the CMIR-6 at temperatures between 420 and 835C to fast neutron doses ranging from 16 to 33 dpa. The post-irradiation ring tensile tests were carried out at irradiation temperatures.

Maintenance of used components in spallation neutron source; Moderator reflector and proton beam window

Teshigawara, Makoto; Kinoshita, Hidetaka; Wakui, Takashi; Meigo, Shinichiro; Seki, Masakazu; Harada, Masahide; Ito, Manabu; Suzuki, Toru; Ikezaki, Kiyomi; Maekawa, Fujio; et al.

JAEA-Technology 2012-024, 303 Pages, 2012/07

JAEA-Technology-2012-024.pdf:46.04MB

3 GeV Protons with 1 MW beam power are irradiated to mercury target of spallation neutron source in Materials and Life science Facility (MLF), which is one of facilities of J-PARC. Irradiated components, such as target container, moderator, reflector and proton beam window, are needed to replace periodically due to irradiation damage of high energy protons and neutrons. These used components are replaced remotely because of highly activated. Maintenance scenario was settled so as to handle these components. Required remote handling machines were designed and installed in hot cell and other room of the MLF. We performed remote handling tests by using actual components to confirm the design. We report results, such as replacement procedure, trouble and its solution, etc., for moderator, reflector and proton beam window in order to provide the handling of actual used components.

Effect of the laser contrast ratio within picosecond timescales on generating a high-quality electron beam by laser-plasma interaction

Kotaki, Hideyuki; Kando, Masaki; Daito, Izuru; Kameshima, Takashi*; Kawase, Keigo*; Chen, L. M.*; Fukuda, Yuji; Koga, J. K.; Kiriyama, Hiromitsu; Kondo, Shuji; et al.

Japanese Journal of Applied Physics, 50(6), p.066401_1 - 066401_3, 2011/06

https://doi.org/10.1143/JJAP.50.066401

Propagation behaviour of general and localised corrosion of carbon steel in simulated groundwater under aerobic conditions

Taniguchi, Naoki; Suzuki, Hiroyuki; Kawasaki, Manabu; Naito, Morimasa; Kobayashi, Masato*; Takahashi, Rieko*; Asano, Hidekazu*

Corrosion Engineering, Science and Technology, 46(2), p.117 - 123, 2011/04

https://doi.org/10.1179/1743278210Y.0000000011

Carbon steel has been selected as one of the candidate materials for overpack for geological disposal of high-level radioactive waste in Japan. Corrosion of carbon steel is divided into two types; general corrosion and localized corrosion. In this study, propagation behaviors of general and localized corrosions (pitting corrosion and crevice corrosion) were investigated by immersion tests of carbon steel under aerobic condition. The results of the immersion tests showed that the growth rate of corrosion was strongly dependent on the environmental condition and steel type, but the upper limit of pitting factor (the ratio of the maximum corrosion depth and the average corrosion depth) was approximately determined by only average corrosion depth. Based on these experimental data and literature data, an empirical model that predicts the maximum corrosion depth of an overpack from average corrosion depth was developed by applying the extreme value statistical analysis using the Gumbel distribution function.

Corrosion behavior of carbon steel in compacted bentonite saturated with simulated groudwater under anaerobic condition

Taniguchi, Naoki; Kawasaki, Manabu; Naito, Morimasa

Zairyo To Kankyo, 59(11), p.418 - 429, 2010/11

https://doi.org/10.3323/jcorr.59.418

Immersion tests of carbon steel were performed in compacted bentonite for 10 years duration under anaerobic condition. The ferrous carbonates were identified as the corrosion product by XRD and XPS analysis in almost test cases. The amount of corrosion in high carbonate concentration was smaller than those of other test conditions throughout the test periods. Although the corrosion rate at 50C was initially smaller than that at 80C, it resulted in larger value after several years. Such the effects of carbonate content and temperature on the long-term corrosion rate seemed to be correlated to the behavior of dissolution/precipitation of iron carbonate. Additionally, the correlation between initial corrosion amount and the protectiveness of corrosion product film was examined. Except for high carbonate condition, as the corrosion amount at early stage of immersion was larger, the corrosion product film tended to become more protective. The long-term corrosion depth was estimated by the extrapolation of the laboratory test results. The range of the estimated value was well agreed with that of archaeological analogue data.

Measured and simulated transport of 1.9 MeV laser-accelerated proton bunches through an integrated test beam line at 1 Hz

Nishiuchi, Mamiko; Sakaki, Hironao; Hori, Toshihiko; Bolton, P.; Ogura, Koichi; Sagisaka, Akito; Yogo, Akifumi; Mori, Michiaki; Orimo, Satoshi; Pirozhkov, A. S.; et al.

Physical Review Special Topics; Accelerators and Beams, 13(7), p.071304_1 - 071304_7, 2010/07

https://doi.org/10.1103/PhysRevSTAB.13.071304

A laser-driven repetition-rated 1.9 MeV proton beam line composed of permanent quadrupole magnets (PMQs), a radio frequency (rf) phase rotation cavity, and a tunable monochromator is developed to evaluate and to test the simulation of laser-accelerated proton beam transport through an integrated system for the first time. In addition, the proton spectral modulation and focusing behavior of the rf phase rotationcavity device is monitored with input from a PMQ triplet. In the 1.9 MeV region we observe very weakproton defocusing by the phase rotation cavity. The final transmitted bunch duration and transverse profile are well predicted by the PARMILA particle transport code. The transmitted proton beam duration of 6 ns corresponds to an energy spread near 5% for which the transport efficiency is simulated to be 10%. The predictive capability of PARMILA suggests that it can be useful in the design of future higher energy transport beam lines as part of an integrated laser-driven ion accelerator system.

High temporal and spatial quality petawatt-class Ti:sapphire chirped-pulse amplification laser system

Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki; Shimomura, Takuya; Sasao, Hajime; Tanoue, Manabu*; Kanazawa, Shuhei; Wakai, Daisuke*; Sasao, Fumitaka*; Okada, Hajime; et al.

Optics Letters, 35(10), p.1497 - 1499, 2010/05

https://doi.org/10.1364/OL.35.001497

OPCPA (Optical parametric chirped-pulse amplification) operation with low gain by seeding with high energy, clean pulses is shown to significantly improve the contrast to better than - in a high intensity Ti:sapphire laser system that is based on chirped pulse amplification. In addition to the high contrast broadband high energy output from the final amplifier is achieved with a flat-topped spatial profile of filling factor near 77%. This is the result of pump beam spatial profile homogenization with diffractive optical elements. Final pulse energies exceed 30-Joules indicating capability for reaching peak powers in excess of 500-TW.

High spatiotemporal-quality petawatt-class laser system

Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki; Shimomura, Takuya; Sasao, Hajime; Tanaka, Momoko; Ochi, Yoshihiro; Tanoue, Manabu*; Okada, Hajime; Kondo, Shuji; et al.

Applied Optics, 49(11), p.2105 - 2115, 2010/04

https://doi.org/10.1364/AO.49.002105

We have developed a femtosecond high intensity laser system, which combines both Ti:sapphire chirped-pulse amplification (CPA) and optical parametric chirped-pulse amplification (OPCPA) techniques, that produces more than 30-J broadband output energy, indicating the potential for achieving peak powers in excess of 500-TW. With a cleaned high-energy seeded OPCPA preamplifier as a front-end in the system, for the compressed pulse without pumping the final amplifier we found that the temporal contrast in this system exceeds 10 on the sub-nanosecond timescales, and is near 10 on the nanosecond timescale prior to the peak of the main femtosecond pulse. Using diffractive optical elements for beam homogenization of 100-J level high-energy Nd:glass green pump laser in a Ti:sapphire final amplifier, we have successfully generated broadband high-energy output with a near-perfect top-hat-like intensity distribution.

Anodic polarization behavior and film breakdown potential of pure copper in the simulated geological environment containing carbonate

Kawasaki, Manabu; Taniguchi, Naoki; Naito, Morimasa

Corrosion Engineering, 58(11), p.465 - 482, 2009/11

In order to clarify the influence of environmental factors on the corrosion behavior of copper overpacks in oxidizing environment, potentiodynamic and potentiostatic anodic polarization tests were performed in carbonate aqueous solutions at 80 C. As the results, the passivation was promoted and film breakdown was suppressed in higher carbonate concentrations, in lower chloride ion concentrations, and in higher pH conditions. The sulfate ion tended to promote the film breakdown of copper. The effects of the composition of the test solutions on the anodic polarization curve of copper in bentonite/sand mixture were quite smaller than those in simple aqueous solution. By comparison with previous data for lower temperature condition, it was clarified that passivation of copper was promoted in higher temperature condition, but breakdown potential, Eb was independent of temperature. The Eb, was expressed as a function of the ratio of aggressive ion and inhibiting ion such as [Cl]/[HCO] and [SO]/[HCO], and it was confirmed that the Eb was lowered with increasing the ratio. When the ratio exceeds a certain value, the Eb was no longer able to be determined since the anodic poralization curve becomes active dissolution type. The lower limit of Eb in passive type region was estimated to be about -200 mV vs. SCE. The results of potentiostatic tests showed that pitting corrosion or non-uniform corrosion was observed at the potentials over Eb or second current peak potentials in anodic polarization curve.