JOPSS - Search Results

Journal Articles

Ortho-positronium annihilation in room temperature ionic liquids

Hirade, Tetsuya

Acta Physica Polonica A, 132(5), p.1470 - 1472, 2017/11

https://doi.org/10.12693/APhysPolA.132.1470

Times Cited Count：3 Percentile：28.88(Physics, Multidisciplinary)

The positron annihilation lifetime measurements in RTILs showed very strange results. Finally, positron annihilation age-momentum correlation (AMOC) measurements indicated that it was caused by slow bubble formation in RTILs. Then I discovered the oscillation of o-Ps annihilation rates in room temperature ionic liquids (RTILs) which indicated, probably, the oscillation of the Ps bubble. Stepanov et al. calculated change of the bubble size in many liquids and the oscillation of the bubble was not expected except for a liquid He. It means that the structure of RTILs in nanometer scale is very different from usual liquids. Moreover, o-Ps pick-off annihilation rates seems to be too small for the macroscopic surface tension of RTILs. I am going to discuss what you can study by the positron annihilation methods for the structure of RTILs in nanometer scale.

Journal Articles

Effect of magnetic field on positron lifetimes of Fe, Co and Ni

Li, H.; Maekawa, Masaki; Kawasuso, Atsuo; Tanimura, Naoki*

Journal of Physics; Condensed Matter, 27(24), p.246001_1 - 246001_5, 2015/06

https://doi.org/10.1088/0953-8984/27/24/246001

Times Cited Count：6 Percentile：27.82(Physics, Condensed Matter)

Journal Articles

Positron lifetime measurement on centrifuged Bi $_{3}$ Pb $_{7}$ intermetallic compound

Ono, Masao; Huang, X. S.*; Shibata, Yasuhiro*; Iguchi, Yusuke*; Sakai, Seiji; Maekawa, Masaki; Chen, Z. Q.*; Osakabe, Toyotaka; Kawasuso, Atsuo; Naramoto, Hiroshi*; et al.

Proceedings of 1st International Conference on Diffusion in Solids and Liquids (DSL 2005), p.531 - 533, 2005/07

Recently, we formed atomic-scale graded structures in some miscible alloys and observed the decomposition in Bi $_{3}$ Pb $_{7}$ intermetallic compound by sedimentation of atoms under strong gravitational field. In this study, we measured positron lifetime of centrifuged Bi $_{3}$ Pb $_{7}$ , to which the composition change was very small as it was treated at low temperature. It was found that the positron lifetime became longer than that of starting state. This indicated that the point defects (vacancy or divacancy) increased in the sample by centrifugal treatment. We are now investigating the relationship between increase in point defects and sedimentation of atoms.

JAEA Reports

Reconstruction of CT images by the Bayes-back projection method

Haruyama, Mitsuo; Takase, Misao*; Iwasaki, Shin*; Tobita, Hiroshi

JAERI-Research 2002-022, 91 Pages, 2002/12

JAERI-Research-2002-022.pdf:37.97MB

In the course of research on quantitative assay of non-destructive measurement of radioactive waste, the authors have developed a unique program based on the Bayesian theory for reconstruction of transmission computed tomography (TCT) image. The reconstruction of cross-section images in the CT technology usually employs the Filtered Back Projection method. The new imaging reconstruction program reported here is based on the Bayesian Back Projection method, and it has a function of iterative improvement images by every step of measurement. Namely, this method has the capability of prompt display of a cross-section image corresponding to each angled projection data from every measurement. Hence, it is possible to observe an improved cross-section view by reflecting each projection data in almost real time. The present reconstruction program developed here for the -ray CT can widely applied also to, for instance, the Neutron Imaging and the Positron Emission Tomography (PET).

Journal Articles

Positron Emitting Tracer Imaging System (PETIS) as a tool for plant physiology

Mori, Satoshi*; Nakanishi, Tomoko*; Hayashi, Hiroaki*; Oyama, Takuji*; Uchida, Hiroshi*; Matsuhashi, Shimpei; Sekine, Toshiaki

Radioisotopes, 50(9), p.408 - 418, 2001/09

https://doi.org/10.3769/radioisotopes.50.9_408

no abstracts in English

Journal Articles

Vanadium uptake and an effect of vanadium treatment on $^{18}$ F-labeled water movement in a cowpea plant by positron emitting tracer imaging system (PETIS)

Furukawa, Jun*; Yokota, Harumi*; Tanoi, Keitaro*; Ueoka, Shiori*; Matsuhashi, Shimpei; Ishioka, Noriko; Watanabe, Satoshi; Uchida, Hiroshi*; Tsuji, Atsunori*; Ito, Takehito*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 249(2), p.495 - 498, 2001/08

https://doi.org/10.1023/A:1013276224300

Times Cited Count：16 Percentile：73.13(Chemistry, Analytical)

We present real time Vanadate (V $^{5+}$ ) uptake imaging in a cowpea plant by Positron Emitting Tracer Imaging System (PETIS). Vanadium-48 was produced by bombarding a Sc foil target with 50 MeV -particles at Takasaki Ion accelerators for Advanced Radiation Application (TIARA) AVF cyclotron. Then $^{48}$ V was added to the culture solution to investigate the V distribution in a cowpea plant. The real time uptake of the $^{48}$ V was monitored by PETIS. We measured the distribution of $^{48}$ V in a whole plant after 3, 6 and 20 hours of V treatment by Bio-imaging Analyzer System (BAS). After the 20 hour treatment, vanadate was detected at the up-ground part of the plant. To know the effect of V uptake on plant activity, $^{18}$ F-labeled water uptake was analyzed by PETIS. When a cowpea plant was treated with V for 20 hours before $^{18}$ F-labeled water uptake experiment, the total amount of $^{18}$ F-labeled water absorption was drastically desreased. Results suggest the inhibition of water uptake was mainly caused by the vanadate already moved to the up-ground part of the plant.

Journal Articles

Positron annihilation studies of defects in ion implanted palladium

Abe, Hiroshi; Uedono, Akira*; Uchida, Hirohisa*; Komatsu, A.*; Okada, Sohei; Ito, Hisayoshi

Materials Science Forum, 363-365, p.156 - 158, 2001/05

no abstracts in English

Journal Articles

Visualization of $^{15}$ O-water flow in tomato and rice in the light and dark using a positron-emitting tracer imaging system (PETIS)

Mori, Satoshi*; Kiyomiya, Shoichiro*; Nakanishi, Hiromi*; Ishioka, Noriko; Watanabe, Satoshi; Osa, Akihiko; Matsuhashi, Shimpei; Hashimoto, Shoji; Sekine, Toshiaki; Uchida, Hiroshi*; et al.

Soil Science and Plant Nutrition, 46(4), p.975 - 979, 2000/12

https://doi.org/10.1080/00380768.2000.10409163

Times Cited Count：29 Percentile：57.23(Plant Sciences)

no abstracts in English

Journal Articles

The Principle in the use of positron-emitting nuclides

Sekine, Toshiaki

Nihon Dojo Hiryo Gaku Zasshi, 71(6), p.928 - 929, 2000/11

no abstracts in English

JAEA Reports

Proceedings of the Symposium on the Joint Research Project between JAERI and Universities; Status and Perspective of the Advanced Radiation Technology Project, January 27, 1999, National Education Center, Tokyo, Japan

Committee for the Joint Research Project on the Advanced Radiation Technology; Committee for the Collaborative Research on the Advanced Radiation Technology

JAERI-Conf 2000-008, 113 Pages, 2000/06

JAERI-Conf-2000-008.pdf:11.5MB

no abstracts in English

Journal Articles