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Am-Li neutron sourceTsujimura, Norio; Yoshida, Tadayoshi
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no abstracts in English
Watanabe, Shigeki; Hanaoka, Hirofumi*; Liang, J. X.; Iida, Yasuhiko*; Watanabe, Satoshi; Endo, Keigo*; Ishioka, Noriko
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no abstracts in English
Hirade, Tetsuya; Lee, J.
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Positronium (Ps) formed in water and OH radical are a geminate radical pair. The geminate radical pair is in a singlet state initially. Both of the spins are in different conditions and then the spin state changes between singlet and triplet. The rotational frequency of Ps is much faster than that of OH radical and a half has the same direction of the rotation and the other half have the opposite direction. The measured phenomenon is the mixture of the both cases and then there will be swells on the probability of the singlet state. The radical reaction of Ps and OH radical is affected by the spin state and then the swells of the spin state can be detected by the positron annihilation experiment as quantum beats. The quantum beats in water were successfully observed.
Hirade, Tetsuya; Lee, J.
no journal, ,
The quantum beats caused by the hyperfine coupling of OH radicals in water were observed by the time resolved positron annihilation 
-ray Doppler broadening measurements. There were two kinds of beats observed at 18
C and 25C. The hyperfine coupling constants of OH radicals are smaller at higher temperatures. These things indicate the two-state model of water structure. If there is a continuous state of water structure it should be impossible to measure the quantum beats. It is possible to say that there are two states of water structure and the structures are affected by temperatures.
Hanaya, Hiroaki; Seito, Hajime; Kaneko, Hirohisa; Haruyama, Yasuyuki; Kanazawa, Takao; Kojima, Takuji; Sunaga, Hiromi*
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Kawamura, Hiroshi
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no abstracts in English
value of hydroxyl radical at high temperatureMuroya, Yusa*; Takahashi, Hiroyuki*; Katsumura, Yosuke; Lin, M.; Kumagai, Yuta; Kudo, Hisaaki*
no journal, ,
Water coolant in light water cooled reactors is exposed to high-dose radioactive field, and oxidant products produced in water radiolysis are significant factor to induce and accelerate corrosion of constructional materials of the reactors. Therefore, it is inevitably important to figure out and to control water radiolysis and involved reactions at elevated temperatures. Especially, hydroxyl radical (
OH) is important species because of its the strongest oxidant property among water decomposition products. However, detailed properties and reactivity of the radical are not known well at the temperatures of 200 C or higher. In this work, reactivity of OH and p value for dissociative reaction between OH and O
have been evaluated up to 300 C with pulse radiolysis technique.
Kawasuso, Atsuo; Maekawa, Masaki; Arashima, Hironobu*; Ito, Hideaki*; Kabutomori, Toshiki*
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Namba, Hideki
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Radioisotopes, -rays and charged particles, e.g. electron-beams and ion-beams, have the longest history of use in quantum beams. The results obtained were not limited in the field of academic research works, but also broadened in the fields of industrial, agricultural and medical activities as products visible in our daily life. Japan Atomic Energy Agency is conducting the researches for biotechnology contributing to the life science and medical applications, for materials development contributing to the environment protection, resources and energy, as well as the development of advanced beam-technologies needed to develop these researches by using ion beam irradiation facilities, named TIARA, electron beam and irradiation facilities in Takasaki Advanced Radiation Research Institute. This paper reports the resent research and development in JAEA-Takasaki in the fields of biotechnology, materials science, as well as new beam-technologies related to support the applications.
Lin, M.; Katsumura, Yosuke; Muroya, Yusa*; Fu, H.*; Yamashita, Shinichi; Yan, Y.*
no journal, ,
In the present work, we have investigated the optical absorption spectral shift of 4,4'-bipyridyl radical at elevated temperature and supercritical water. The results show that the spectral shift is mainly due to the change of water properties, especially the dielectric constant. Local density effect on the spectral shift has been also observed.
Sr and 
Sr in effluent by a liquid scintilation counterNakano, Masanao; Hiyama, Yoshinori; Watanabe, Hitoshi; Sumiya, Shuichi; Takeishi, Minoru*
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Kawasaki, Masatsugu; Watanabe, Yoko; Shimizu, Rumi
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I in soil using an accelerator mass spectrometryKokubun, Yuji; Nakano, Masanao; Sumiya, Shuichi; Takeishi, Minoru*
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no abstracts in English
Hirose, Akira; Komeda, Masao; Kinase, Masami; Sorita, Takami; Sagawa, Hisashi; Wada, Shigeru
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no abstracts in English
Fukaya, Yuki; Kawasuso, Atsuo; Ichimiya, Ayahiko
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no abstracts in English
Yamashita, Shinichi; Maeyama, Takuya*; Baldacchino, G.*; Katsumura, Yosuke; Muroya, Yusa*; Taguchi, Mitsumasa; Kimura, Atsushi; Murakami, Takeshi*
no journal, ,
A novel sensitive method to determine OH yield in water radiolysis has been developed and has been applied for heavy-ion irradiations. In this work, this method was extended to measurement near the Bragg peak. It was found that OH yield has minimum value near the Bragg peak and is different even for the same ion irradiation of different acceleration energies.
Maeyama, Takuya*; Yamashita, Shinichi; Baldacchino, G.*; Katsumura, Yosuke; Muroya, Yusa*; Taguchi, Mitsumasa; Kimura, Atsushi; Murakami, Takeshi*
no journal, ,
OH yield near the Bragg peak of high-energy heavy ions, of which energies are comparable to those used in cancer therapy, has been determined in the previous work. Because fragmentations of primary projectile are significant in the energy region, it was purposed to calculate the fragmentations with an existing code and to reproduce the already obtained experimental results for verification of the code as well as for estimation of how much each fragmentated ions contributes in terms of OH yield.
Midorikawa, Masamichi*; Yamashita, Shinichi; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Maeyama, Takuya*; Funtowiez, D.*; Kamibayashi, Masato*; Anzai, Kazunori*
no journal, ,
no abstracts in English
Tamoto, Yukihiro*; Sakamoto, Yuki*; Katsumura, Yosuke; Domae, Masafumi*; Akutagawa, Daisuke*; Ohira, Taku*; Hisamune, Kenji*
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no abstracts in English
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.