Mechanism of enhanced positronium formation in low-temperature polymers
Mechanism of enhanced positronium formation in low-temperature polymers
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DOI：
10.1063/1.1924553
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发表时间：
2005-06-01
影响因子：
4.4
通讯作者：
Matsuo, M
中科院分区：
文献类型：
--
作者：
He, CQ;Shantarovich, VP;Matsuo, M
人们广泛观察到低温聚合物中正电子素（Ps）的形成增强。额外的正电子素形成是由于其中浅层俘获的电子造成的。应用正电子湮灭寿命光谱研究了低密度聚乙烯、不同甲基丙烯酸甲酯含量的乙烯-甲基丙烯酸甲酯共聚物以及纯聚甲基丙烯酸甲酯等一系列聚合物在低温下的Ps形成。基于简单动力学方程的实验数据分析使人们能够了解低温正电子湮灭实验中聚合物中 Ps 形成机制作为温度和经过时间的函数。获得了实验数据的良好拟合。拟合参数似乎显示出明确的物理意义。 (c) 2005 年美国物理研究所。
An enhanced positronium (Ps) formation in low-temperature polymers has been widely observed. The additional positronium formation is due to shallow trapped electrons in them. Positron annihilation lifetime spectroscopy was applied to investigate the Ps formation in a series of polymers, such as low-density polyethylene, ethylene-methyl methacrylate copolymers with various methyl methacrylate contents, and pure poly(methyl methacrylate) at low temperature. An analysis of the experimental data based on simple kinetic equations enables one to understand the Ps formation mechanism in polymers during low-temperature positron annihilation experiments as functions of the temperature and elapsed time. Good fittings of the experimental data were obtained. The fitting parameters seemed to show clear physical meanings. (c) 2005 American Institute of Physics.