Estimation of external dose for wild Japanese macaques captured in Fukushima prefecture; Decomposition of electron spin resonance spectrum

Mitsuyasu, Yusuke*; Oka, Toshitaka; Takahashi, Atsushi*; Kino, Yasushi*; Okutsu, Kenichi*; Sekine, Tsutomu*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; et al.

Radiation Protection Dosimetry, 199(14), p.1620 - 1625, 2023/09

https://doi.org/10.1093/rpd/ncad146

We have been conducting dose assessments for Japanese macaques captured in Fukushima to reveal radiobiological effects on the low-dose expose animals. To accurately determine the external exposure dose, it is desirable to examine the analysis of the CO radical intensity. We examined ESR spectra of teeth of 10 macaques captured in Fukushima by two spectrum-decomposition algorithms.

Detection limit of electron spin resonance for Japanese deciduous tooth enamel and density separation method for enamel-dentine separation

Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; Osaka, Ken*; Sasaki, Keiichi*; et al.

Journal of Radiation Research (Internet), 63(4), p.609 - 614, 2022/07

https://doi.org/10.1093/jrr/rrac033

Electron spin resonance (ESR) dosimetry is one of the most powerful tools for radiation dose reconstruction. The detection limit of this technique using human teeth is reported to be 56 mGy or 67 mGy; however, the absorbed dose of Fukushima residents after the Fukushima Daiichi Nuclear Power Plant (FNPP) accident was estimated to be lower than this detection limit. Our aim is to assess the absorbed radiation dose of children in Fukushima Prefecture after the accident; therefore, it is important to estimate the detection limit for their teeth. The detection limit for enamel of deciduous teeth of Japanese children separated by the mechanical method is estimated to be 115.0 mGy. The density separation method can effectively separate enamel from third molars of Japanese people. As we have collected thousands of teeth from children in Fukushima, the present technique may be useful to examine their external absorbed dose after the FNPP accident.

Rapid analysis of Sr in cattle bone and tooth samples by inductively coupled plasma mass spectrometry

Koarai, Kazuma; Matsueda, Makoto; Aoki, Jo; Yanagisawa, Kayo*; Terashima, Motoki; Fujiwara, Kenso; Kino, Yasushi*; Oka, Toshitaka; Takahashi, Atsushi*; Suzuki, Toshihiko*; et al.

Journal of Analytical Atomic Spectrometry, 36(8), p.1678 - 1682, 2021/08

https://doi.org/10.1039/D1JA00086A

Rapid analysis of Sr in bone and tooth samples of cattle were achieved by an inductively coupled plasma mass spectrometry (ICP-MS) coupled with mass shift and solid phase extraction techniques. Limit of detection (LOD) in the ICP-MS measurement of 0.1 g samples was lower than that of the radioactivity measurement. Analytical time of the ICP-MS method was reduced from 20 days to 11 hours, compared with the radiometric method. Therefore, the ICP-MS method can be rapid and useful procedure of Sr in small bone and tooth samples derived from terrestrial animals.

External exposure dose estimation by electron spin resonance technique for wild Japanese macaque captured in Fukushima Prefecture

Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Mitsuyasu, Yusuke*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; Osaka, Ken*; et al.

Radiation Measurements, 134, p.106315_1 - 106315_4, 2020/06

https://doi.org/10.1016/j.radmeas.2020.106315

The relationship between the CO radical intensity and the absorbed dose (dose response curve) of tooth enamel of Japanese macaque was observed by electron spin resonance and the detection limit of our system was estimated to be 33.5 mGy, which is comparable to the detection limit for human molar teeth. Using the dose response curve, external exposure dose for seven wild Japanese macaques captured in Fukushima prefecture were examined. The results suggest that the external exposure dose for the wild Japanese macaques were ranged between 45 mGy to 300 mGy.

Uniaxial-pressure control of magnetic phase transitions in a frustrated magnet CuFeGaO (x =0, 0.018)

Nakajima, Taro*; Mitsuda, Setsuo*; Takahashi, Keiichiro*; Yoshitomi, Keisuke*; Masuda, Kazuya*; Kaneko, Chikafumi*; Homma, Yuki*; Kobayashi, Satoru*; Kitazawa, Hideaki*; Kosaka, Masashi*; et al.

Journal of the Physical Society of Japan, 81(9), p.094710_1 - 094710_8, 2012/09

https://doi.org/10.1143/JPSJ.81.094710

Photoelectron-photoion coincidence momentum imaging for dissociative ionization of ethanol in intense laser fields

Hosaka, Koichi; Itakura, Ryuji; Yokoyama, Keiichi; Yamanouchi, Kaoru*; Yokoyama, Atsushi

Chemical Physics Letters, 475(1-3), p.19 - 23, 2009/06

https://doi.org/10.1016/j.cplett.2009.05.008

In intense laser fields, molecules are decomposed into fragments through a number of competing dissociative ionization pathways. We investigate the dissociative ionization dynamics of ethanol in intense laser fields with photoelectron-photoion coincidence momentum imaging. The channel-specific photoelectron spectra reveal the electronic states prepared just after ionization, depending both on the decomposition pathways and on the temporal profile of laser pulses.

Determination of crystal structure and charge density of (BaSr)(CoFe)O by Rietveld refinement and maximum entropy method analysis

Ito, Takanori*; Nishida, Yuki*; Tomita, Aya*; Fujie, Yoshinori*; Kitamura, Naoto*; Idemoto, Yasushi*; Osaka, Keiichi*; Hirosawa, Ichiro*; Igawa, Naoki

Solid State Communications, 149(1-2), p.41 - 44, 2009/01

https://doi.org/10.1016/j.ssc.2008.10.020

The crystal structure and charge density of (BaSr)(CoFe)O were investigated by the Rietveld refinement method and the maximum entropy method by using neutron and synchrotron X-ray diffraction. The crystal structure was refined by using the split atom model to cation sites with the space group, . The site occupancies of O1(4) and O2(8) sites were 0.59 and 0.87, respectively. It was found that the (Co, Fe)-O2 plane in the sample has anisotropic covalent and ionic bands, and that the (Ba, Sr)-O1 bond was ionic with a low charge density.

Photoelectron-photoion coincidence momentum imaging for dissociative ionization in intense laser fields

Hosaka, Koichi; Itakura, Ryuji; Yokoyama, Keiichi; Yamanouchi, Kaoru*; Yokoyama, Atsushi

no journal, , 

When molecules are exposed to intense laser fields, dissociative ionization is efficiently induced and several decomposition pathways competes. The present study aims at revealing the correlation between the electronic states just after ionization and the following dissociation process. The photoelectron-photoion coincidence momentum imaging (PEPICO-MI) technique enables us to detect photoelectrons and photoions produced in a single event simultaneously. We applied PEPICO-MI to dissociative ionization of ethanol (CHOH), whose branching ratio varies as a function of the laser pulse duration. When ethanol molecules are irradiated with a short laser pulse, photoelectron images strongly depend on the correlated product ions.

Dissociative ionization of ethanol in intense laser fields by photoelectron-photoion coincidence momentum imaging

Hosaka, Koichi; Itakura, Ryuji; Yokoyama, Keiichi; Yamanouchi, Kaoru*; Yokoyama, Atsushi

no journal, , 

In intense laser fields, molecules are decomposed into fragments through a number of competing dissociative ionization pathways. We investigate the dissociative ionization dynamics of ethanol in intense laser fields with photoelectron-photoion coincidence momentum imaging. The channel-specific photoelectron spectra reveal the electronic states prepared just after ionization, depending both on the decomposition pathways and on the temporal profile of laser pulses.

Fragment momentum specific photoelectron imaging of ethanol in intense laser field

Hosaka, Koichi; Itakura, Ryuji; Yokoyama, Keiichi; Yamanouchi, Kaoru*; Yokoyama, Atsushi

no journal, , 

In intense laser fields, molecules are decomposed into fragments through a number of competing dissociative ionization pathways. We have investigated the dissociative ionization dynamics of ethanol in intense laser fields with photoelectron-photoion coincidence momentum imaging. The fragment momentum specific photoelectron images reveal the correlation between the electronic states prepared just after ionization and the following dissociation dynamics of ethanol cation.