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Accession number;99A1007985
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| Title;Positronium trapped in free volume holes. Study of the formation in extreme cases. |
| Author;
GOWOREK T
(High Energy Accelerator Res. Organization (kek), Tsukuba)
SUZUKI T
(High Energy Accelerator Res. Organization (kek), Tsukuba)
KONDO K
(High Energy Accelerator Res. Organization (kek), Tsukuba)
HAMADA E
(Graduate Univ. Advanced Studies, Tsukuba)
ITO Y
(Univ. Tokyo, Ibaraki)
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Journal Title;Abstracts of Papers. Symposium on Radiochemistry
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Journal Code:F0139B
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ISSN:1345-2762
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VOL.43rd;NO.;PAGE.70(1999)
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| Figure&Table&Reference; |
| Pub. Country;Japan |
| Language;English |
| Abstract;The measurements of positron lifetime spectra in biphenyl as a function of external pressure were performed. We have observed that already at 0.1 kbar the intensity of long lived component and its lifetime drop to very low values. There are two possibilities to explain the effect: a) at 0.1 kbar a phase transition occurs, or b) at normal pressure we are very near the threshold of Ps formation; application of pressure reduces further the free spaces, up to the moment when the trap volume is not sufficient to accommodate Ps atom. This second possibility seems most probable. In the case of very large voids in the structure of solid it is necessary to account the location of Ps on the excited levels of particle in the potential well which leads to dimi-nishing the o-Ps lifetime with the increase of temperature. As an example of this dependence one can give the porous glass of Vycor type. (author abst.) |
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