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Journal Articles

Structure and magnetic properties of Fe nanoparticles in amorphous silica implanted with Fe ions and effect of subsequent energetic heavy ion irradiation

Iwase, Akihiro*; Fukuda, Kengo*; Saito, Yuichi*; Okamoto, Yoshihiro; Semboshi, Satoshi*; Amekura, Hiroshi*; Matsui, Toshiyuki*

Journal of Applied Physics, 132(16), p.163902_1 - 163902_10, 2022/10

 Times Cited Count:0 Percentile:0.00(Physics, Applied)

Amorphous SiO$$_{2}$$ samples were implanted with 380 keV Fe ions at room temperature. After implantation, some of the samples were irradiated with 16 MeV Au ions. magnetic properties were investigated using a SQUID magnetometer, and the morphology of the Fe-implanted SiO$$_{2}$$ samples was examined using transmission electron microscopy and X-ray absorption spectroscopy (EXAFS and XANES), which showed that the size of Fe nanoparticles was increasing The size of Fe nanoparticles increased with increasing Fe implantation amount; some of the Fe nanoparticles consisted of Fe oxides, and the valence and structure of Fe atoms became closer to that of metallic $$alpha$$-Fe with increasing Fe injection amount. The magnetization-field curve of the sample implanted with a small amount of Fe was reproduced by Langevin's equation, suggesting that the Fe nanoparticles behave in a superparamagnetic manner. In addition, when a large amount of Fe was implanted, the magnetization-magnetic field curve shows a ferromagnetic state. These magnetic property results are consistent with the X-ray absorption results. Subsequent 16 MeV Au irradiation crushed the Fe nanoparticles, resulting in a decrease in magnetization.

Journal Articles

Neutron irradiation effect of high-density MoO$$_{3}$$ pellets for Mo-99 production, 3

Ishida, Takuya; Suzuki, Yoshitaka; Nishikata, Kaori; Yonekawa, Minoru; Kato, Yoshiaki; Shibata, Akira; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; et al.

KURRI Progress Report 2015, P. 64, 2016/08

no abstracts in English

Journal Articles

Neutron irradiation effect of high-density MoO$$_{3}$$ pellets for Mo-99 production, 2

Nishikata, Kaori; Ishida, Takuya; Yonekawa, Minoru; Kato, Yoshiaki; Kurosawa, Makoto; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.

KURRI Progress Report 2014, P. 109, 2015/07

As one of effective applications of the Japan Materials Testing Reactor (JMTR), JAEA has a plan to produce $$^{99}$$Mo by (n,$$gamma$$) method ((n,$$gamma$$)$$^{99}$$Mo production), a parent nuclide of $$^{99m}$$Tc. In this study, preliminary irradiation test was carried out with the high-density molybdenum trioxide (MoO$$_{3}$$) pellets in the hydraulic conveyer (HYD) of the Kyoto University Research Reactor (KUR) and the $$^{99m}$$Tc solution extracted from $$^{99}$$Mo was evaluated. After the irradiation test of the high-density MoO$$_{3}$$ pellets in the KUR, $$^{99m}$$Tc was extracted from the Mo solution and the recovery rate of $$^{99m}$$Tc achieved the target values. The $$^{99m}$$Tc solution also got the value that satisfied the standard value for $$^{99m}$$Tc radiopharmaceutical products by the solvent extraction method.

Journal Articles

Neutron irradiation effect of high-density MoO$$_{3}$$ pellets for Mo-99 production

Nishikata, Kaori; Ishida, Takuya; Yonekawa, Minoru; Kato, Yoshiaki; Kurosawa, Makoto; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.

KURRI Progress Report 2013, P. 242, 2014/10

As one of effective applications of the Japan Materials Testing Reactor (JMTR), JAEA has a plan to produce Mo-99 ($$^{99}$$Mo) by (n,$$gamma$$) method ((n,$$gamma$$)$$^{99}$$Mo production), a parent nuclide of $$^{99m}$$Tc. In this study, preliminary irradiation tests were carried out with the high-density MoO$$_{3}$$ pellets in the KUR and the $$^{99}$$Mo production amount was evaluated between the calculation results and measurement results.

Journal Articles

Investigation of strand bending in the He-inlet during reaction heat treatment for ITER TF Coils

Hemmi, Tsutomu; Matsui, Kunihiro; Kajitani, Hideki; Okuno, Kiyoshi; Koizumi, Norikiyo; Ishimi, Akihiro; Katsuyama, Kozo

IEEE Transactions on Applied Superconductivity, 24(3), p.4802704_1 - 4802704_4, 2014/06

 Times Cited Count:1 Percentile:9.39(Engineering, Electrical & Electronic)

Japan Atomic Energy Agency (JAEA), as Japan Domestic Agency, has responsibility to procure nine ITER Toroidal Field (TF) coils. The TF coil winding consists of a Nb$$_{3}$$Sn Cable-In-Conduit conductor, a pair of joints and a He-inlet. The current capacity of 68 kA is required at the magnetic field of 7 T around the He-inlet region in the TF coil winding. During reaction heat-treatment, the compressive residual strain in Nb$$_{3}$$Sn cable is induced by the difference in the thermal expansion coefficients between the Nb$$_{3}$$Sn cable and stainless steel jacket. The strands bending in the Nb$$_{3}$$Sn cable of the He-inlet is anticipated since there is the compressive residual strain and a gap between the Nb$$_{3}$$Sn cable and the He-inlet to introduce SHE flow. If the strand is bent, the variation of mechanical behaviors, such as the elongation of He-inlet during the reaction heat-treatment and the thermally induced residual strain on the jacket around the He-inlet, are expected. To investigate the strands bending in the Nb$$_{3}$$Sn cable of the He-inlet, the following items are performed; (1) elongation measurement during reaction heat-treatment, (2) residual longitudinal strain measurement using strain gauges by sample cuttings, (3) nondestructive inspection on the cable and strands using high resolution X-ray CT, Detail of test results and investigation of the strands bending in the Nb$$_{3}$$Sn cable of the He-inlet are reported and discussed.

Journal Articles

Magnetic patterning of FeRh thin films by energetic light ion microbeam irradiation

Koide, Tetsuya*; Sato, Takahiro; Koka, Masashi; Saito, Yuichi; Kamiya, Tomihiro; Okochi, Takuo*; Kotsugi, Masato*; Kinoshita, Toyohiko*; Nakamura, Tetsuya*; Iwase, Akihiro*; et al.

Japanese Journal of Applied Physics, 53(5S1), p.05FC06_1 - 05FC06_4, 2014/05

 Times Cited Count:12 Percentile:46.80(Physics, Applied)

We previously reported that the magnetic state of FeRh can be controlled by irradiation with ion beams. In this paper, we evaluate possibility of magnetic patterning on FeRh thin films using energetic light ion microbeam irradiation with various shapes and dimensions. Proton microbeam irradiation with 2 MeV was performed at JAEA-Takasaki to produce micron-sized magnetic patterns. XMCD-PEEM observation was performed at SPring8 to confirm the synthesized magnetic patterns. As a result, the XMCD-PEEM images of the various micrometer sized patters in FeRh film were observed using 2 MeV H ion beam. The observed bright regions are considered to have ferromagnetic spin orders, in contrast that the gray areas have anti-ferromagnetic spin order. Since the brightness of the PEEM images is strongly correlated with the magnetization of the samples, we reveal that the magnetic state in local regions of the FeRh thin films can be controlled by changing the ion fluences.

Journal Articles

Study on ferromagnetic ordering of FeRh thin films induced by energetic heavy ion irradiation by means of X-ray magnetic circular dichroism

Aiko, Kazuma*; Toki, Atsushi*; Okuda, Shuichi*; Saito, Yuichi; Kamiya, Tomihiro; Nakamura, Tetsuya*; Kinoshita, Toyohiko*; Iwase, Akihiro*; Matsui, Toshiyuki*

Nuclear Instruments and Methods in Physics Research B, 314, p.99 - 102, 2013/11

 Times Cited Count:5 Percentile:38.30(Instruments & Instrumentation)

Journal Articles

Development of $$^{99m}$$Tc production from (n,$$gamma$$)$$^{99}$$Mo based on solvent extraction

Kimura, Akihiro; Awaludin, R.*; Shiina, Takayuki*; Tanase, Masakazu*; Kawauchi, Yukimasa*; Gunawan, A. H.*; Lubis, H.*; Sriyono*; Ota, Akio*; Genka, Tsuguo; et al.

Proceedings of 3rd Asian Symposium on Material Testing Reactors (ASMTR 2013), p.109 - 115, 2013/11

JP, 2011-173260   Patent publication (In Japanese)

$$^{99m}$$Tc is generated by decay of $$^{99}$$Mo. Production of $$^{99}$$Mo is carried out by (n,f) method with high enriched uranium targets, and the production are currently producing to meet about 95% of global supply. Recently, it is difficult to carry out a stable supply for some problems such as aging of reactors etc. Furthermore, the production has difficulties in nuclear proliferation resistance etc. Thus, (n,$$gamma$$) method has lately attracted considerable attention. The (n,$$gamma$$) method has several advantages, but the extremely low specific activity makes its uses less convenient than (n,f) method. We proposed a method based on the solvent extraction, followed by adsorption of $$^{99m}$$Tc with alumina column. In this paper, a practical production of $$^{99m}$$Tc was tried by the method with 1Ci of $$^{99}$$Mo produced in MPR-30. The recovery yields were approximately 70%. Impurity of $$^{99}$$Mo was less than 4.0$$times$$10$$^{-5}$$% and the radiochemical purity was over 99.2%.

Journal Articles

Effect of salt-containing filter paper attached to osmotic membrane

Sano, Kenji*; Yamada, Arisa*; Matsui, Akihiro*; Tsuji, Hideyuki*; Hasegawa, Shin; Sawada, Shinichi; Maekawa, Yasunari

Desalination, 324, p.34 - 36, 2013/09

 Times Cited Count:3 Percentile:14.09(Engineering, Chemical)

Anchored osmotic pressure inducer was examined. Salt-containing filter paper attached to an osmotic membrane increased the water flux to more than 10% at 1 MPa. The salt-containing filter paper was fabricated via graft polymerization of acrylic acid onto a filter paper followed by alkaline treatment. The filter paper was characterized by thermo gravimetric analysis (TGA), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), scanning electronic microscopy-energy dispersive X-ray spectrometry(SEM-EDS).

Journal Articles

Magnetic Compton scattering studies of magneto-dielectric Ba(Co$$_{0.85}$$Mn$$_{0.15}$$)O$$_{3-delta}$$

Shinoda, Ryoichi*; Ito, Masayoshi*; Sakurai, Yoshiharu*; Yamamoto, Hiroyuki; Hirao, Norie; Baba, Yuji; Iwase, Akihiro*; Matsui, Toshiyuki*

Journal of Applied Physics, 113(17), p.17E307_1 - 17E307_3, 2013/05

 Times Cited Count:9 Percentile:37.75(Physics, Applied)

We revealed that the Ba(Co$$_{0.85}$$Mn$$_{0.15}$$)O$$_{3-delta}$$ (BCMO) ceramic samples exhibited ferromagnetic-dielectric behavior below the magnetic transition temperature of about 35 K. The origin of their magnetic ordering was expected to super-exchange coupling of Co$$^{4+}$$($$d^5$$)-O$$^{2-}$$-Mn$$^{4+}$$ ($$d^3$$) with bonding angle of 180$$^{circ}$$. and/or Mn$$^{4+}$$($$d^3$$)-O$$^{2-}$$-Mn$$^{4+}$$ ($$d^3$$) with bonding angle of 90$$^{circ}$$. The magnetic spin momentum estimated by the magnetic Compton profiles (MCP) of the samples had similar temperature dependence as that determined by the SQUID measurement, which meant that the observed magnetic moments could be ascribed to the spin moment. The shapes of the MCPs of the samples were completely same regardless of the temperature measured. This result indicates that there are no changes of the momentum space distribution of spin density between ferromagnetic and paramagnetic states. So, this magnetic transition is simply caused by a thermal fluctuation of the spin.

Journal Articles

MFM observation of micrometer-sized magnetic patterns produced by heavy ion microbeam irradiation in FeRh films

Aiko, Kazuma*; Toki, Atsushi*; Matsui, Toshiyuki*; Iwase, Akihiro*; Sato, Takahiro; Takano, Katsuyoshi*; Koka, Masashi; Saito, Yuichi; Kamiya, Tomihiro

JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 133, 2013/01

Journal Articles

Change in magnetic properties induced by swift heavy ion irradiation in CeO$$_{2}$$

Shimizu, Hirotaka*; Kosugi, Shinya*; Tahara, Yuki*; Yasunaga, Kazufumi*; Kaneta, Yasunori*; Ishikawa, Norito; Hori, Fuminobu*; Matsui, Toshiyuki*; Iwase, Akihiro*

Nuclear Instruments and Methods in Physics Research B, 286, p.291 - 294, 2012/09

 Times Cited Count:27 Percentile:87.31(Instruments & Instrumentation)

We have studied the magnetic properties of pure CeO$$_{2}$$ irradiated with swift heavy ions. Experiment a results showed that the ferromagnetism was induced even at room temperature by 200 MeV Xe ion irradiation. The value of saturation magnetization, Ms, systematically changes as a function of ion-fluence. The X-ray diffraction (XRD) spectra show that the lattice constant of CeO$$_{2}$$ increases with increasing ion-fluence. This result and our previous XPS result show that the ion-irradiation produced oxygen vacancies. The present study implies that the ferromagnetic behavior of the ion-irradiated CeO$$_{2}$$ is attributed to the magnetic moments of localized 4f electrons on Ce$$^{3+}$$ atoms, which are related to oxygen vacancies.

JAEA Reports

Experimental study on dilution coefficients measurement of capsule dilution tube for fuel transient tests

Inoue, Shuichi; Omuro, Tadao; Nabeya, Hideaki; Matsui, Yoshinori; Iida, Kazuhiro; Ito, Kazuyuki; Kimura, Akihiro; Kanno, Masaru

JAEA-Technology 2010-010, 27 Pages, 2012/05

JAEA-Technology-2010-010.pdf:1.99MB

In fuel irradiation transient tests using a boiling water capsule, a dilution tube has been installed in the boiling water capsule in order to detect fission products (FP) from an irradiated fuel, in case of the fuel failure during the transient, by a radiation monitor located outside the reactor. When the fuel failure occurs, the released FP flows out from the capsule through the dilution tube. The dilution tube is designed to minimize the released FP that can be detected by the radiation monitor located outside the reactor. This report summarized the measurement results of the dilution tube installed in the boiling water capsule.

Journal Articles

Study on effects of energetic ion irradiation in Gd$$_2$$O$$_3$$-doped CeO$$_2$$ by means of synchrotron radiation X-ray spectroscopy

Tahara, Yuki*; Shimizu, Hirotaka*; Ishikawa, Norito; Okamoto, Yoshihiro; Hori, Fuminobu*; Matsui, Toshiyuki*; Iwase, Akihiro*

Nuclear Instruments and Methods in Physics Research B, 277, p.53 - 57, 2012/04

 Times Cited Count:11 Percentile:63.06(Instruments & Instrumentation)

To study the effects of Gd$$_2$$O$$_3$$-doping and the irradiation with high energy fission products in the nuclear fuels (UO$$_2$$), Gd$$_2$$O$$_3$$-doped CeO$$_2$$ pellets were irradiated with 200 MeV Xe$$^{14+}$$ ions. Effects of Gd$$_2$$O$$_3$$-doping and the ion irradiation were estimated by using Extended X-ray Absorption Fine Structure (EXAFS) measurement. The interatomic distances between each Ce and the first nearest O atoms, and Ce and the second nearest Ce atoms increase by the irradiation and the effect of the ion irradiation on the atomic distances is more pronounced for higher amounts of dopant. The Debye-Waller factors for Ce-O and Ce-Ce pairs increase with increasing the amount of Gd$$_2$$O$$_3$$ dopant. These results suggest that the lattice binding energy is weakened by Gd$$_2$$O$$_3$$-doping. The Debye-Waller factors increase also by the irradiation. The effect of ion irradiation on the Debye-Waller factors, however, becomes smaller for higher amounts of dopant.

Journal Articles

Study on effects of energetic ion irradiation in Gd$$_{2}$$O$$_{3}$$-doped CeO$$_{2}$$ by means of synchrotron radiation X-ray spectroscopy

Tahara, Yuki*; Shimizu, Hirotaka*; Ishikawa, Norito; Okamoto, Yoshihiro; Hori, Fuminobu*; Matsui, Toshiyuki*; Iwase, Akihiro*

Nuclear Instruments and Methods in Physics Research B, 277, p.53 - 57, 2012/04

In this study, to simulate such an environment, Gd$$_{2}$$O$$_{3}$$-doped CeO$$_{2}$$ samples were irradiated with 200 MeV Xe$$^{14+}$$ ions at room temperature using an ion beam accelerator at JAEA-Tokai. As CeO$$_{2}$$ has the same fluorite structure as that of UO$$_{2}$$ and several properties of CeO$$_{2}$$ are similar to UO$$_{2}$$, in this study CeO$$_{2}$$ was used as a simulation material of UO$$_{2}$$. To study the effects of the ion irradiation on Gd$$_{2}$$O$$_{3}$$-doped CeO$$_{2}$$, extended X-ray absorption fine structure (EXAFS) and X-ray photoelectron spectroscopy (XPS) were used at the Photon Factory of High Energy Accelerator Research Organization (KEK) as well as conventional X-ray diffraction (XRD) measurement. The EXAFS and XRD spectra show that the effects of the ion irradiation are more pronounced for higher amount of Gd$$_{2}$$O$$_{3}$$ dopant.

Journal Articles

MFM and PEEM observation of micrometre-sized magnetic dot arrays fabricated by ion-microbeam irradiation in FeRh thin films

Aiko, Kazuma*; Toki, Atsushi*; Matsui, Toshiyuki*; Iwase, Akihiro*; Sato, Takahiro; Takano, Katsuyoshi*; Koka, Masashi; Saito, Yuichi; Kamiya, Tomihiro; Okochi, Takuo*; et al.

Journal of Synchrotron Radiation, 19(2), p.223 - 226, 2012/03

 Times Cited Count:7 Percentile:36.52(Instruments & Instrumentation)

Journal Articles

Swift heavy ion irradiation effect on structural properties for epitaxial Ba(Fe$$_{0.5}$$Mn$$_{0.5}$$)O$$_{3-delta}$$ thin film

Matsui, Toshiyuki*; Iwase, Akihiro*; Yamamoto, Hiroyuki; Hirao, Norie; Baba, Yuji

Photon Factory Activity Report 2011, Part B, P. 243, 2012/00

no abstracts in English

Journal Articles

Stability test of RHQT Nb$$_{3}$$Al cable-in-conduit conductor

Koizumi, Norikiyo; Matsui, Kunihiro; Hemmi, Tsutomu; Nakajima, Hideo; Takeuchi, Takao*; Banno, Nobuya*; Kikuchi, Akihiro*

Teion Kogaku, 46(8), p.495 - 499, 2011/08

JAEA and NIMS has been collaborating in development of high performance Rapid-Heating-Quenching-Transformation (RHQT) Nb$$_{3}$$Al CIC conductor, aiming at the application of this conductor to DEMO plant. The technical issue of the RHQT Nb$$_{3}$$Al strand in the application to a fusion magnet is stabilization against perturbation. NIMS developed technique to attach copper stabilizer by using electroplating and a sub-scale CIC conductor is developed using this conductor. JAEA performed stability test of the developed CIC conductor to demonstrate efficiency of this copper stabilization technique. The measured stability margin is sufficiently high compared to the one of similar NbTi CIC conductor previously tested by the authors. Then, it can be concluded that the copper stabilizer works efficiently from view point of stability, resulting in solving the remained technical issues in the RHQT CIC conductor. Therefore, we can say that the RHQT Nb$$_{3}$$Al CIC conductor is the most promising candidate for application to magnet in DEMO plant.

Journal Articles

Effect of high temperature annealing on ferromagnetism induced by energetic ion irradiation in FeRh alloy

Kosugi, Shinya*; Fujita, Naoki*; Matsui, Toshiyuki*; Hori, Fuminobu*; Saito, Yuichi; Ishikawa, Norito; Okamoto, Yoshihiro; Iwase, Akihiro*

Nuclear Instruments and Methods in Physics Research B, 269(9), p.869 - 872, 2011/05

 Times Cited Count:10 Percentile:60.56(Instruments & Instrumentation)

Effects of thermal annealing on ion-irradiation induced ferromagnetism of FeRh bulk alloy and the related structural change were investigated by means of superconducting quantum interference device (SQUID) and extended X-ray absorption fine structure (EXAFS), respectively. Depending on the annealing temperature from 100 to 500 $$^{circ}$$C, the magnetization induced by 10 MeV iodine ion irradiation and the lattice structure of the alloy were remarkably changed. After 500 $$^{circ}$$C annealing, the magnetization and the lattice ordering of the alloy become similar to the states before the irradiation. The experimental result indicates that the thermal relaxation of irradiation-induced atomic disordering dominates the magnetic state of ion-irradiated FeRh alloy.

Journal Articles

Study on effects of swift heavy ion irradiation on the crystal structure in CeO$$_{2}$$ doped with Gd$$_{2}$$O$$_{3}$$

Tahara, Yuki*; Zhu, B.-L.*; Kosugi, Shinya*; Ishikawa, Norito; Okamoto, Yoshihiro; Hori, Fuminobu*; Matsui, Toshiyuki*; Iwase, Akihiro*

Nuclear Instruments and Methods in Physics Research B, 269(9), p.886 - 889, 2011/05

 Times Cited Count:16 Percentile:75.56(Instruments & Instrumentation)

CeO$$_{2}$$ pellets doped with Gd$$_{2}$$O$$_{3}$$ were irradiated with 200-MeV Xe ions, and the effects of Gd$$_{2}$$O$$_{3}$$-doping and irradiation on the lattice structure were measured using XRD and EXAFS. The lattice constant decreases with increasing Gd$$_{2}$$O$$_{3}$$-doping and the local structure near the Gd atoms is more disordered with increasing amounts of Gd$$_{2}$$O$$_{3}$$-dopant. The irradiation induces an expansion of the lattice and disordering of the atomic arrangement around Gd atoms. The effect of high-energy ion irradiation becomes more pronounced with increasing amounts of Gd$$_{2}$$O$$_{3}$$-dopant.

37 (Records 1-20 displayed on this page)