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Information × Registration Number 0223U000090, 0121U112015 , R & D reports Title Spectroscopy of positron lifetime in structural materials of atomics popup.stage_title Head Lebed Oleksandr A., Доктор фізико-математичних наук Registration Date 03-01-2023 Organization Institute of Applied Physics National Academy of Sciences of Ukraine popup.description2  Analytical approaches have been developed to calculate the lifetime of a positron in a material taking into account local changes in the electron density associated with its defective structure. The Tao-Eldrup model was developed, which allows analytically calculating the lifetime of a positron in a spherically symmetric potential well, in the case when tunneling through the boundaries of the potential well into the base material and into the well is taken into account. It is shown thatthe value of the life time increases rather quickly when the height or width of the potential well increases. The developed modified model provides important information for the analysis of positron lifetime spectra in irradiated materials and data for verification of quantitative calculations by density functional methods, which are widely used for such tasks. It is shown that the ABINIT software package allows calculating the distribution of electron and positron density near vacancies in various types of materials. In turn, this makes it possible to determine the characteristic height and width of the well for comparing the analytical results of calculating the lifetime of positrons in the defects of the structural materials of the reactors with the results of modeling, which will be used in the prediction and analysis of the results of experimental measurements for irradiated samples. Product Description popup.authors Vorona Maryna I. Krukla Sergey V. Ovcharenko Artur Yu. popup.nrat_date 2023-01-03 Close