Autor: Hamada, E. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: The Effect of Visible Light Irradiation on Positronium Formation in Polyethylene at Low Temperature
Autorzy:: Ito, Y.
Hirade, T.
Hamada, E.
Suzuki, T.
Powiązania:: https://bibliotekanauki.pl/articles/2007996.pdf
Data publikacji:: 1999-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 78.70.Bj
Opis:: The effect of visible light exposing on the ortho-positronium formation in polyethylene was studied. Lifetime spectra of positrons in polyethylene were measured in the temperature range between 50 K and 370 K. It was observed that the visible light quenches the enhancement of ortho-positronium intensity (I$\text{}_{3}$) at lower temperature than ca. 250 K - the glass transition temperature of polyethylene. On the other hand, the lifetime of ortho-positronium component (τ$\text{}_{3}$) was not affected by the presence of the visible light.
Źródło:: Acta Physica Polonica A; 1999, 95, 4; 533-538
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Positron Irradiation Effects on Positronium Formation in Polycarbonate Sduring a Positron-Annihilation Experiment
Autorzy:: Suzuki, T.
Kondo, K.
Hamada, E.
Ito, Y.
Powiązania:: https://bibliotekanauki.pl/articles/2025767.pdf
Data publikacji:: 2001
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 78.70.Bj
Opis:: The positron-irradiation effect on polycarbonate during a positron-annihilation lifetime spectroscopy experiment was investigated using different intensities of $\text{}^{22}$Na positron sources andγ-irradiated samples. The decrease in I$\text{}_{3}$ was larger for a larger intensity of positron sources. In the case of a weak source (≈ 140 kBq), I$\text{}_{3}$ did not change with the elapsed time for non-irradiated samples. However, for 1 MGy irradiated samples, I$\text{}_{3}$ measured with the weak source increased with the elapsed time. This can be attributed to a decrease in the radicals induced in the irradiated samples by γ-irradiation. In order to explain the change in I$\text{}_{3}$ measured at room and liquid-nitrogen temperatures, several effects, such as radicals, cross-linking, structure change, and charging, need to be considered. Also, it is difficult to explain the change in I$\text{}_{3}$ using only one of these effects.
Źródło:: Acta Physica Polonica A; 2001, 99, 3-4; 515-521
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Application of a Pulsed Slow-Positron Beam to Low-Density Polyethylene Film
Autorzy:: Hamada, E.
Oshima, N.
Katoh, K.
Suzuki, T.
Kobayashi, H.
Kondo, K.
Kanazawa, I.
Ito, Y.
Powiązania:: https://bibliotekanauki.pl/articles/2024257.pdf
Data publikacji:: 2001
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 78.70.Bj
Opis:: A pulsing system for a slow-positron beam was applied to study the region near the surface of low-density polyethylene film using positron-annihilation lifetime measurement. The lifetime and intensity of ortho-positronium near the surface were measured as a function of the incident positron energy (1.6-9.1 keV). The size of intermolecular spaces in the surface region (~ 1500 nm) was larger than that in the bulk region. This tendency was especially strong in the region around 200 nm below the surface. On the other hand, the intensity of ortho-positronium decreased at lower incident positron energies, which was attributed to a decrease in the density of the spur electrons and/or an increase in the number of reemitted positrons from the surface.
Źródło:: Acta Physica Polonica A; 2001, 99, 3-4; 373-378
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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