- Tytuł:
- Relationship between Enhanced Positronium Formation and Enhanced Positron Trapping in Polymers at Low Temperature
- Autorzy:
-
Kansy, J.
Suzuki, T. - Powiązania:
- https://bibliotekanauki.pl/articles/2047130.pdf
- Data publikacji:
- 2006-11
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
78.70.Bj
71.60.+z
61.80.Fe - Opis:
- Positron annihilation lifetime spectroscopy is used for investigation of low-density polyethylene and ethylene-methyl methacrylate copolymers of 1.45, 3.0, and 5.4 mole% of methyl methacrylate. The lifetime spectra are collected at 30 K, one by one, as a function of elapsed time. In the computer analysis a new theoretical model is developed, which enables separating the annihilation from positron free state, its trapped state and bound state in positronium. The positron trapping rateμ and the enhanced positronium formation rateκ are determined. The calculated values of μ andκ turned out to be linearly correlated. This correlation presumably originates from an influence of trapped electrons on the trapping of positrons. The dependences ofκ on measurement time are determined for low-density polyethylene and ethylene-methyl methacrylate of different methyl methacrylate content. A theoretical model describing quantitatively the dependences is proposed. The model considers the processes of electron-ion recombination, electron trapping, and electron scavenging by dipolar carbonyl groups supplied by methyl methacrylate additives.
- Źródło:
-
Acta Physica Polonica A; 2006, 110, 5; 593-604
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł