正电子湮没寿命谱分析结果的正确表示

Correct expression of analytical results of positron annihilation lifetime spectra

正电子湮没寿命的多寿命成分分析结果通常给出各成分的寿命τi及其零时相对湮没强度Ii(O).指出用零时相对或绝对湮没强度讨论分析结果并不合理,只有正电子在各湮没态上的零时相对占有数Ni(O)=τiIi(O)或占有率ni(O)=Ni(O)/∑Ni(O)才有明确的物理意义,因为正电子在态上的几率密度ni(O)与正电子湮没环境介质的结构特性密切相关.并以二态捕获模型为例对上述论点作了证明.

It is indicated in this paper that relative annihilation intensity, Ii(0), which comes from the analysis of the lifetime spectrum and is usually regarded as a basis of discussion on the experiment, dose not always have exact physical meaning. Instead, either the relative population of positrons in the ith state, Ni(0), or the probability density of positrons distributed in the states, ni(0), being equal to Ni(0)/∑Ni(0) = τiIi(0)/∑Ni(0), has obvious connection physically with the structure and characters of the annihilation medium. A proof of the above propositions based on the two- state capture model is given.