Stepanov P S, Selim F A, Stepanov S V, Bokov A V, Ilyukhina O V, Duplâtre G, Byakov V M
Center for Photochemical Sciences, Department of Physics and Astronomy, Bowling Green State University, OH 43403, USA.
Phys Chem Chem Phys. 2020 Mar 7;22(9):5123-5131. doi: 10.1039/c9cp06105c. Epub 2020 Feb 19.
The interaction of positronium (Ps) with molecular oxygen dissolved in liquids is experimentally investigated. Computer software has been developed for fitting the positron annihilation lifetime spectra in liquids using parameters with clear physical meaning: rate constants of the Ps chemical reactions, annihilation rate constants of the different positron states, probability of Ps formation in a quasi-free state, typical formation time of a Ps nanobubble. Such processing of the spectra allowed identification of the dominant interaction of the Ps atom with dissolved oxygen. It turns out to be mainly ortho-para-conversion (Ps → 1/4 p-Ps + 3/4 o-Ps), but not oxidation (Ps + O→ e + O). Values of the reaction rate constants are obtained.
对正电子素（Ps）与溶解在液体中的分子氧之间的相互作用进行了实验研究。已开发出计算机软件，用于使用具有明确物理意义的参数来拟合液体中的正电子湮没寿命谱：Ps化学反应的速率常数、不同正电子态的湮没速率常数、准自由态下Ps形成的概率、Ps纳米气泡的典型形成时间。这种对谱的处理使得能够识别Ps原子与溶解氧之间的主要相互作用。结果表明，主要是仲-正转换（Ps→1/4对-正电子素+3/4邻-正电子素），而不是氧化（Ps+O→e+O）。获得了反应速率常数的值。
