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Journal Articles

Crystal structure change of katoite, Ca$$_{3}$$Al$$_{2}$$(O$$_{4}$$D$$_{4}$$)$$_{3}$$, with temperature at high pressure

Kyono, Atsushi*; Kato, Masato*; Sano, Asami; Machida, Shinichi*; Hattori, Takanori

Physics and Chemistry of Minerals, 46(5), p.459 - 469, 2019/05

 Times Cited Count:1 Percentile:12.33(Materials Science, Multidisciplinary)

To reveal the decomposition mechanism with temperature under high-pressure, crystal structure of a hydrogrossular, katoite Ca$$_{3}$$Al$$_{2}$$(O$$_{4}$$D$$_{4}$$)$$_{3}$$ has been studied by in-situ neutron diffraction at 8 GPa. Although unusual expansion behavior was discerned at 200-400$$^circ$$C, the unit cell was continuously expanded up to 850$$^circ$$C. At 900$$^circ$$C, katoite was decomposed, indicating that pressure strongly increases dehydration temperature from 300$$^circ$$C to 900$$^circ$$C. On release of pressure, the katoite reappear together with corundum and portlandite. At 8 GPa, CaO$$_{8}$$ and AlO$$_{6}$$ polyhedra expand with temperature up to 850$$^circ$$C by about 8% and 13%, respectively. On the other hand, tetrahedral interstices are isotopically squeezed by about 10%: due to the expansion of above polyhedra. The neighboring D-D distance remains almost unchanged in this temperature range, while the O-D bond distance shrinks drastically just before decomposition. This finding suggests that the shortening of O-D distance caused by the D-D repulsion destabilizes the O-D bond, which induces the thermal decomposition of katoite.

Journal Articles

High-pressure-high-temperature study of benzene; Refined crystal structure and new phase diagram up to 8 GPa and 923 K

Chanyshev, A. D.*; Litasov, K. D.*; Rashchenko, S.*; Sano, Asami; Kagi, Hiroyuki*; Hattori, Takanori; Shatskiy, A. F.*; Dymshits, A. M.*; Sharygin, I. S.*; Higo, Yuji*

Crystal Growth & Design, 18(5), p.3016 - 3026, 2018/05

 Times Cited Count:14 Percentile:88.87(Chemistry, Multidisciplinary)

The high-temperature structural properties of solid benzene were studied at 1.5-8.2 GPa up to melting or decomposition using multi-anvil apparatus and in situ neutron and X-ray diffraction. The crystal structure of deuterated benzene phase II (P2$$_{1}$$/c unit cell) was refined at 3.6-8.2 GPa and 473-873 K. Our data show a minor temperature effect on the change in the unit cell parameters of deuterated benzene at 7.8-8.2 GPa. At 3.6-4.0 GPa, we observed the deviation of deuterium atoms from the benzene ring plane and minor zigzag deformation of the benzene ring, enhancing with the temperature increase caused by the displacement of benzene molecules and decrease of van der Waals bond length between the $$pi$$-conjuncted carbon skeleton and the deuterium atom of adjacent molecule. Deformation of benzene molecule at 723-773 K and 3.9-4.0 GPa could be related to the benzene oligomerization at the same conditions. In the pressure range of 1.5-8.2 GPa, benzene decomposition was defined between 773-923 K. Melting was identified at 2.2 GPa and 573 K. Quenched products analyzed by Raman spectroscopy consist of carbonaceous material. The defined benzene phase diagram appears to be consistent with those of naphthalene, pyrene, and coronene at 1.5-8 GPa.

Journal Articles

Improvement of high-voltage performance of acceleration tubes by cleaning the walls with a high-pressure water jet

Takeuchi, Suehiro; Nakanoya, Takamitsu; Kabumoto, Hiroshi; Yoshida, Tadashi

Nuclear Instruments and Methods in Physics Research A, 513(3), p.429 - 438, 2003/11

 Times Cited Count:2 Percentile:21.84(Instruments & Instrumentation)

At the JAERI Tandem accelerator, an acceleration tube replacing plan is proceeding to increase the acceleration voltage toward 20 MV. Lengthy conditioning is generally necessary for a large tube system. We had an idea to clean the tubes with high-pressure water-jet rinsing before installation. We cleaned tubes and tested them at 1 MV and 3 MV. The both results exhibited that the voltages went beyond the rated voltages and discharge activities were much less than the old records. During the test of new tubes at 3 MV, the conditioning proceeded well and an extremely stable condition was fulfilled within 24 hours. In conclusion, the cleaning was found to be a very promising way to improve high-voltage performance of the tubes in a large tube system.

Journal Articles

Replacement of accelerator tubes of the JAERI tandem accelerator with tubes cleaned by a high-pressure water jet

Takeuchi, Suehiro; Nakanoya, Takamitsu; Kabumoto, Hiroshi; Ishizaki, Nobuhiro; Matsuda, Makoto; Tsukihashi, Yoshihiro; Kanda, Susumu; Tayama, Hidekazu; Abe, Shinichi; Yoshida, Tadashi

Dai-14-Kai Kasokuki Kagaku Kenkyu Happyokai Hokokushu, p.308 - 310, 2003/00

no abstracts in English

Journal Articles

Pressure-variation of structure factor of liquid Rb

*; G.Kahl*

Japanese Journal of Applied Physics, 38(SUPPL.38-1), p.492 - 495, 1999/00

 Times Cited Count:182 Percentile:98.05(Physics, Applied)

no abstracts in English

JAEA Reports

Core void fraction distribution under high-temperature high-pressure boil-off conditions; Experimental study with two-phase flow test facility(TPTF)

; Kumamaru, Hiroshige; Murata, Hideo; Anoda, Yoshinari; Kukita, Yutaka

JAERI-M 93-200, 56 Pages, 1993/10

JAERI-M-93-200.pdf:1.85MB

no abstracts in English

Journal Articles

Fiber-optics video probes for observation of high-pressure high-temperature two-phase flow

Nakamura, Hideo; Murata, Hideo; Ito, Hideo; Anoda, Yoshinari; Kumamaru, Hiroshige; Kukita, Yutaka

Kashika Joho Gakkai-Shi, 12(47), p.47 - 56, 1992/10

no abstracts in English

Journal Articles

Post-dryout heat transfer of steam-water two-phase flow in rod bundle under high-pressure and low-flow conditions

Kumamaru, Hiroshige; Kukita, Yutaka

ANS Proc. 1991 National Heat Transfer Conf., Vol. 5, p.22 - 29, 1991/00

no abstracts in English

Journal Articles

Fiber-optics video probes for observation of high-pressure two-phase flow

Nakamura, Hideo; Murata, Hideo; Ito, Hideo; Anoda, Yoshinari; Kumamaru, Hiroshige; Kukita, Yutaka

ANS Proc. 1991 National Heat Transfer Conf., Vol. 5, p.175 - 180, 1991/00

no abstracts in English

Journal Articles

Slug to annular flow transition during boiloff in a rod bundle under high-pressure conditions

Osakabe, Masahiro; Koizumi, Yasuo; ; ; Tasaka, Kanji

Nucl.Eng.Des., 98, p.69 - 76, 1986/00

 Times Cited Count:3 Percentile:41.55(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Investigation of uncovered-bundle heat transfer under high-pressure boil-off conditions

; Koizumi, Yasuo; ; Osakabe, Masahiro; Tasaka, Kanji

Nucl.Eng.Des., 96, p.81 - 94, 1986/00

 Times Cited Count:3 Percentile:41.55(Nuclear Science & Technology)

no abstracts in English

JAEA Reports

Fabrication and Performance Test of NSRR High-Temperatur High-Pressure Loop

; ;

JAERI-M 83-039, 118 Pages, 1983/03

JAERI-M-83-039.pdf:3.07MB

no abstracts in English

Oral presentation

Construction of high-pressure neutron diffractometer PLANET and the realization of high-pressure and high-temperature neutron experiments

Hattori, Takanori; Sano, Asami; Arima, Hiroshi*

no journal, , 

High-Pressure Neutron Diffractometer PLANET constructed at BL11 in MLF is the first neutron spectrometer dedicated to high-pressure and high-temperature (high-PT) experiments. This aims at revealing the effects of water on the physical properties of the Earth. The beamline is equipped with the multi-anvil press "ATSUHIME" that can generate high-PT condition very stably, and is able to conduct high-PT neutron experiments at 16 GPa and 1000$$^{circ}$$C. The most characteristic feature of the beamline is, beside the above high-PT generation capability, that we can obtain very clean diffraction patterns with no Bragg peaks from sample surroundings, such as a heater and anvils. These characters enable us to analyze the structure not only of crystals, but also of liquids and amorphous solids. In this talk, I will introduce the performance of the spectrometer, recent results and future plan of the PLANET, together with the history of the construction.

Oral presentation

High-pressure inelastic experiments using a Paris-Edinburgh press and clamp cell

Hattori, Takanori; Nakamura, Mitsutaka; Iida, Kazuki*; Kawamura, Seiko; Sano, Asami; Machida, Shinichi*

no journal, , 

Since the pressure reduces the distance between atoms in a substance and directly changes the interatomic interaction, it is possible to greatly change the state of the substance with individual structure and physical properties. The response is a good clue to understand the mechanism of physical properties. Although inelastic scattering is effective for investigating the dynamics of a substance, experiments under high pressure have been limited mainly for three reasons: inelastic scattering is weak, high pressure specimens are small, neutron sources are weak. However, if we use spectrometers (BL01, 14) with high S/N ratio at J-PARC MLF, an inelastic scattering experiment under high pressure seems to be possible. Thus, we performed the feasibility test using a Paris Edinburgh press and clamp cell. In this talk, the results will be introduced.

Oral presentation

Current status of the high-pressure neutron diffractometer PLANET at J-PARC

Hattori, Takanori; Sano, Asami; Machida, Shinichi*; Abe, Jun*; Funakoshi, Kenichi*; Arima, Hiroshi*

no journal, , 

10 years has passed since the operation of J-PARC, and 5 years has passed since the PLANET started the user program. After the completion of the beamline in 2013, the developments in devices and techniques of the high-pressure neutron experiments have been done. In this talk, the recent developments and current status are introduced.

Oral presentation

Recent developments and current status of high-pressure neutron diffractometer PLANET in J-PARC

Hattori, Takanori; Sano, Asami; Machida, Shinichi*; Abe, Jun*; Funakoshi, Kenichi*; Arima, Hiroshi*

no journal, , 

The first domestic high-pressure powder neutron diffractometer PLANET celebrated five years since its operation started. Here, we will introduce the current status and subsequent progress. Expansion of measurable PT region: In the experiments using a 6-axis press, in-situ observation at 14 GPa, 1800 K became possible by increasing the anvil strength by shrink fitting and replacing a graphite with a TiC + Al$$_{2}$$O$$_{3}$$ heater. In experiments using the Paris Edinburgh Press (PE press), by reducing the anvil top to 2.5 mm in diameter, experiments at 30 GPa are possible. Improvement of measurement data quality: when using a PE press, samples are normally pressurized together with liquid pressure medium to avoid peak broadening. However, above 10 GPa, the medium solidifies and the peaks are broadened. To fix this problem, a system capable of heating the sample up to 100$$^{circ}$$C was designed and now we can obtain sharp diffraction peaks up to 20 GPa. New measurement method: In order to obtain macroscale information of samples under high PT condition, we attempted neutron radiograph. By using a compact neutron camera, we can place a camera close to the sample and obtain high resolution images.

Oral presentation

Current status and utilization results of BL11 PLANET

Hattori, Takanori

no journal, , 

The PLANET is a powder diffraction beamline dedicated to high-pressure experiments constructed at MLF in J-PARC. The most important feature is to enable the in-situ observation of the state of matter at high pressure and high temperature (10 GPa, 2000 K) by neutron diffraction and neutron imaging using a 6-axis multi anvil press (max. load is 500 ton per axis). The PLANET is also equipped with a radial collimator with a gauge length of 1.5 mm to 3.0 mm, which make it possible to obtain a clean diffraction pattern without signals from materials around the sample (heater and pressure medium etc.). Thanks to this character, it is possible to analyze the structure of crystals and liquid / amorphous solids very accurately even under high pressure. By exchanging a 6-axis press with a small press, high-pressure experiments are possible over wide temperature range from 77 K to 2000 K. In this lecture, I will introduce recent achievements obtained at the PLANET.

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