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Kai, Takeshi; Ishida, Akira*; Oshima, Nagayasu*
no journal, ,
When a positron was injected into the condensed phase, positronium (Ps) which constructs of an electron and a positron was generated. Although we expect that Bose-Einstein condensation (BEC) using the densely positroniums creates newly physics such as gravity accurate measurement of antimatter and annihilation gamma-rays laser, the BEC have never been achieved. The aims of this study are that fundamental explication of Ps generation as well as elucidation of experimental condition for Ps - BEC achievement from the positrons deceleration simulation in the condensed phase. For the aims, we applied a dynamic Monte Carlo code of the electrons to deceleration simulation of positrons bunch. We present current states of development of the high dense positrons transport simulation in the condensed phase.
Hirade, Tetsuya
no journal, ,
The annihilation lifetime of triplet Ps (o-Ps) in water observed by the positron annihilation lifetime (PALS) measurement shows opposite temperature dependence of other usual liquids, i.e. shorter lifetimes at higher temperatures. This is because o-Ps reacts with surrounding active species in water. In the positron annihilation lifetime-momentum correlation (AMOC) measurement, in particular, singlet Ps (p-Ps) formed by spin exchange reaction is detected effectively, and it is predicted that temperature dependence is observed like PALS measurement. In fact, above about 10
C, the formation of p-Ps by the spin exchange reaction decreased with lowering temperatures. However, at around 6C, the formation of p-Ps by the spin exchange reaction increased again. The reason of this phenomenon is that the reaction with the OH radical with the electron having a spin correlation with the electron in o-Ps preferentially occurs. Hence, three-dimensional diffusion dominates the reaction above 10C and OH radical on the surface of water cluster preferentially reacts with o-Ps below 10C.
Ishida, Tsuyoshi; Sakoda, Akihiro; Kataoka, Takahiro*; Kanzaki, Norie; Tanaka, Hiroshi; Yunoki, Yuto*; Mitsunobu, Fumihiro*; Yamaoka, Kiyonori*
no journal, ,
We focused on the sebum layer and examined the solubility of radon in the components and its temperature dependence in order to clarify the effect of radon water on skin. As a result, the solubility of radon water by sebum component showed the maximum value for methyl myristate and squalene at each temperature, and the minimum value for triolein. In addition, it could also be suggested that triolein is greatly involved in the solubility of radon in sebum.
Kaburagi, Masaaki; Shimazoe, Kenji*; Otaka, Yutaka*; Foong, W. S.*; Uenomachi, Mizuki*; Kamada, Kei*; Kin, J. Y.*; Yoshino, Masao*; Yoshikawa, Akira*; Takahashi, Hiroyuki*; et al.
no journal, ,
no abstracts in English
Miura, Hikaru*; Kuribara, Yuichi; Yamamoto, Masayoshi*; Sakaguchi, Aya*; Higaki, Shogo*; Takahashi, Yoshio*
no journal, ,
A synchrotron radiation X-ray analysis was performed on radioactive particles released into the environment due to the Fukushima Dai-ichi Nuclear Power Plant accident, uranium particles (4 valence and 6 valence) with a size of several microns were present in the particles from the Unit 1. Since these uranium particles also contain zirconium, which is considered to be derived from the fuel cladding, it was presumed that the eutectic mixture of the fuel in the reactor and its cladding was incorporated into the radioactive particulates and released into the environment.
