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Oka, Toshitaka; Jinno, Satoshi*; Fujinami, Masanori*
Analytical Sciences, 25(7), p.837 - 844, 2009/07
Times Cited Count：13 Percentile：16.31(Chemistry, Analytical)Positrons have been used for material analysis not only because of their novel characteristics, such as an ability to detect open-volume type defects in materials, but also because interactions with solids differ from those of electrons in such processes as scattering and diffraction. Monoenergetic positron beams and microbeams were developed in the 1980s, and positron experiments have made progress in material analyses. In this article we review the fundamental technique of microbeam fabrication, especially using a magnetically-guided positron beam, its extension to various analytical methods, and expectations for future research.
Ito, Kenji*; Oka, Toshitaka*; Kobayashi, Yoshinori*; Shirai, Yasuharu*; Wada, Kenichiro*; Matsumoto, Masataka*; Fujinami, Masanori*; Hirade, Tetsuya; Honda, Yoshihide*; Hosomi, Hiroyuki*; et al.
Materials Science Forum, 607, p.248 - 250, 2009/00
So far no standard procedure for the positron annihilation lifetime (PAL) technique has been established. A lack of the standards has led to difficulty in ensuring the equivalency and reliability of data from different laboratories. As a first, we conducted an interlaboratory comparison of PAL measurements for metal, polymer and silica glass with agreed procedures for data recording and analysis. The PAL data recorded at different laboratories were analyzed with a single lifetime component for the metal sample and with three components for the others, respectively. Based on the results of the reported positron and ortho-positronium lifetimes, the possible sources of the uncertainties in the PAL measurements are discussed. To reduce the effect of scattered 
rays, a lead shield was placed between the detectors. The uncertainty was significantly decreased, signifying that placing lead shields between the detectors effectively reduced the false signals due to the scattered rays.
Ito, Kenji*; Oka, Toshitaka*; Kobayashi, Yoshinori*; Shirai, Yasuharu*; Wada, Kenichiro*; Matsumoto, Masataka*; Fujinami, Masanori*; Hirade, Tetsuya; Honda, Yoshihide*; Hosomi, Hiroyuki*; et al.
Journal of Applied Physics, 104(2), p.026102_1 - 026102_3, 2008/07
Times Cited Count：48 Percentile：83.42(Physics, Applied)Interlaboratory comparison of positron annihilation lifetime measurements using synthetic fused silica and polycarbonate was conducted with the participation of 12 laboratories. By regulating procedures for the measurement and data analysis the uncertainties of the positron lifetimes obtained at different laboratories were significantly reduced in comparison with those reported in the past.
Fujinami, Masanori*; Oguma, Koichi*; Akahane, Takashi*; Kawasuso, Atsuo; Maekawa, Masaki
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 151, 2007/02
no abstracts in English
Fujinami, Masanori*; Miyagoe, Tatsuzo*; Akahane, Takashi*; Kawasuso, Atsuo; Maekawa, Masaki; Chen, Z. Q.*
JAEA-Review 2005-001, TIARA Annual Report 2004, p.235 - 237, 2006/01
no abstracts in English
Ito, Kenji*; Oka, Toshitaka*; Kobayashi, Yoshinori*; Shirai, Yasuharu*; Wada, Kenichiro*; Matsumoto, Masataka*; Fujinami, Masanori*; Hirade, Tetsuya; Honda, Yoshihide*; Hosomi, Hiroyuki*; et al.
no journal, ,
So far no standard procedure for the positron annihilation lifetime (PAL) technique has been established. A lack of the standards has led to difficulty in ensuring equivalency and reliability of data from different laboratories. Recently, as a first step toward the standardization of the PAL technique, we conducted an interlaboratory comparison of PAL measurements for fused silica, polycarbonate and metal with agreed procedures for data recording and analysis. Based on the results of the reported lifetimes, possible sources of the uncertainties in the PAL measurements is probably caused by the backscattered -rays by other detectors. We succeeded to show that inserting shields between detectors can reduce the uncertainty.
Ito, Kenji*; Oka, Toshitaka*; Kobayashi, Yoshinori*; Shirai, Yasuharu*; Wada, Kenichiro*; Matsumoto, Masataka*; Fujinami, Masanori*; Hirade, Tetsuya; Honda, Yoshihide*; Hosomi, Hiroyuki*; et al.
no journal, ,
An interlaboratory comparison for positron annihilation lifetime measurements for pure nickel, polycarbonate (PC) and fused silica was performed. Based on the reported data of positron (for nickel) and positronium (for PC and fused silica) components, the uncertainties in the PAL measurements were estimated and their possible source was discussed.
Oka, Toshitaka; Jinno, Satoshi*; Fujiwara, Aya*; Fujinami, Masanori*
no journal, ,
Temperature dependence of free volume in polyethylene was investigated by positron annihilation lifetime spectroscopy. The relationship between the thermal expansion of free volume and the sample density was clearly shown.
Wada, Ken*; Mochizuki, Izumi*; Hyodo, Toshio*; Kosuge, Takashi*; Saito, Yuki*; Nigorikawa, Kazuyuki*; Shidara, Tetsuo*; Osawa, Satoshi*; Ikeda, Mitsuo*; Shirakawa, Akihiro*; et al.
no journal, ,
no abstracts in English
Hyodo, Toshio*; Fukaya, Yuki; Takahashi, Toshio*; Fujinami, Masanori*; Wada, Ken*; Mochizuki, Izumi*; Shidara, Tetsuo*; Kawasuso, Atsuo; Maekawa, Masaki; Shirasawa, Tetsuro*
no journal, ,
no abstracts in English
Wada, Ken*; Mochizuki, Izumi*; Hyodo, Toshio*; Kosuge, Takashi*; Saito, Yuki*; Shidara, Tetsuo*; Osawa, Satoshi*; Ikeda, Mitsuo*; Shirakawa, Akihiro*; Furukawa, Kazuro*; et al.
no journal, ,
no abstracts in English
Fujinami, Masanori*; Jinno, Satoshi*; Oka, Toshitaka; Kawashima, Yuji*
no journal, ,
Wada, Ken*; Mochizuki, Izumi*; Hyodo, Toshio*; Kosuge, Takashi*; Saito, Yuki*; Shidara, Tetsuo*; Osawa, Satoshi*; Ikeda, Mitsuo*; Shirakawa, Akihiro*; Furukawa, Kazuro*; et al.
no journal, ,
no abstracts in English
Wada, Ken*; Mochizuki, Izumi*; Hyodo, Toshio*; Kosuge, Takashi*; Saito, Yuki*; Nigorikawa, Kazuyuki*; Shidara, Tetsuo*; Osawa, Satoshi*; Ikeda, Mitsuo*; Shirakawa, Akihiro*; et al.
no journal, ,
no abstracts in English
Wada, Ken*; Mochizuki, Izumi*; Hyodo, Toshio*; Kosuge, Takashi*; Saito, Yuki*; Nigorikawa, Kazuyuki*; Shidara, Tetsuo*; Osawa, Satoshi*; Ikeda, Mitsuo*; Shirakawa, Akihiro*; et al.
no journal, ,
no abstracts in English
Yabuuchi, Atsushi*; Awaji, Ryo*; Hirade, Tetsuya; Fujinami, Masanori*; Oshima, Nagayasu*; Takai, Kenichi*; Taira, Yoshitaka*
no journal, ,
In situ measurements of positron annihilation lifetimes have been performed at the UVSOR synchrotron radiation facility to evaluate defects formed during tensile deformation in pure iron using the gamma-ray induced positron annihilation spectroscopy technique. A 66 MeV gamma-ray pulse beam with a diameter of 3 mm was irradiated to the centre of the sample while stretching it to a nominal strain of 7 or more at a strain rate of 2.2
10
/s. The positron lifetime change during the tensile deformation of iron specimens was observed. Positron lifetime measurements have often been performed after the deformation of the sample. Unlike these results, it was found that the lifetime change at the initial deformation stage was very small in these In situ measurements.
Kawasuso, Atsuo; Maekawa, Masaki; Fujinami, Masanori*; Oguma, Koichi*; Akahane, Takashi*; Watanabe, Kazuya*; Matsukawa, Kazuto*
no journal, ,
Transition-metals are ubiquitous in Si devices to degrade their properties. Gettering has proved effective to trap contaminants and it is important to study their interaction. Extended defects such as stacking faults and precipitates have been investigated by TEM and impurity profile is analyzed by SIMS. However, such a approach cannot afford us the interaction of them. PAS is a powerful tool to analyze the defects and their coupled elements. A Cz-Si wafer was implanted with 3MeV Si ions to dose of 1E+14/cm
and Cu ion implantation was done into the back side (200 keV, 1E+14/cm). Variable-energy positron beam was employed and coincidence Doppler broadening spectra were taken at 15 keV after sample annealing. Up to 500
C, no differences between with and without Cu ion implantation are found and the clustering of vacancies takes place. At 600C, the profile is very similar to that for the bulk Cu. At 700C, the trapped Cu are released and oxygen atoms are coupled with vacancy clusters.
Yabuuchi, Atsushi*; Hirade, Tetsuya; Fujinami, Masanori*; Awaji, Ryo*; Oshima, Nagayasu*; Takai, Kenichi*; Taira, Yoshitaka*; Sugita, Kento*
no journal, ,
In situ measurements of positron annihilation lifetimes have been performed at the UVSOR synchrotron radiation facility to characterise defects formed during tensile deformation of pure iron using the gamma-ray induced positron annihilation spectroscopy (GiPAS) technique. A dumbbell-shaped specimen was attached to a small tensile tester and stretched to a nominal strain of 7 or more at a strain rate of 2.210/s. Positron lifetime changes during tensile deformation of a pure iron specimen were observed using positrons generated in the sample by irradiating the centre of the sample with a 66MeV gamma-ray pulse beam of 3mm in diameter. Unlike the results reported so far, the change in the positron lifetime, especially at the early deformation stage, was very small, making clear the importance of in-situ measurement.
Fujinami, Masanori*; Watanabe, Kazuya*; Oguma, Koichi*; Akahane, Takashi*; Kawasuso, Atsuo; Maekawa, Masaki; Matsukawa, Kazuto*; Harada, Hirofumi*
no journal, ,
no abstracts in English
Akahane, Takashi*; Fujinami, Masanori*; Watanabe, Kazuya*; Oguma, Koichi*; Matsukawa, Kazuto*; Harada, Hirofumi*; Maekawa, Masaki; Kawasuso, Atsuo
no journal, ,
no abstracts in English
