The Study Of The Physical Mechanism From The Low-energy Positron Annihilation With The Electrons In Atoms

In the past few decades,the gamma-ray spectra produced when the low-energy positrons in the molecule have been annihilated has been extensively studied,However,there are still many problems that puzzle scientists: First,in most current study of gamma-ray spectra,the experimentally measured values ??generally agree well with the theoretical gamma-ray spectra of the valence electron orbit,which means that the valence electrons dominate the annihilation process.However,why valence electrons play a major role in the annihilation process has not been given a reasonable quantitative explanation in theory.In addition,until now,most studies on gamma-ray spectra have used the full width at half maximum(FWHM)of the spectral line as the physical quantity to describe the gamma-ray spectra.However,FWHM only represents a special point in its spectral line,which has no clear physical meaning and cannot fully reflect the specific characteristics of the spectral line.However,in the recent study of gamma-ray spectra in the process of positron annihilation,the measurement results of its spectra are very accurate,enough to study the linear shape of the spectra,not just the width.Therefore,new physical quantities should be introduced to more accurately describe the gamma-ray spectra.In this paper,the gamma-ray spectra of a series of atoms is studied in combination with the latest Rahm’s electronegativity scale.In this study,the electron orbital energy and kinetic energy distribution of atoms 1-96 are calculated,and their momentum spectra and gamma-ray spectra data are obtained,thereby obtaining the theoretical gamma-ray spectra’s full width at half maximum(Valence FWHM)of a series of atoms.Through comparative analysis of these data and other processes,the research results obtained are as follows:1.Contrast and analyze the experimental measured value FWHM,theoretical predicted value FWHM and electronegativity of the gamma-ray spectra of the inert gas atoms that have been measured in experiments.The results show that the theoretical values of valence electrons are in good agreement with the experimentally measured values.At the same time,the electronegativity of the inert gas atoms has the same variation law as the width of the gamma ray spectra.This means that the valenceelectrons play a leading role in the annihilation process,and the width of the gamma ray spectra is likely related to the electronegativity or the average binding energy of the valence electrons in the atoms.2.For 36 A group atoms in elements 1-56,their gamma-ray spectra FWHM and their electronegativity were compared and analyzed.The results show that the width of the gamma-ray spectra of these atoms and their corresponding electronegativity are consistent,and there is a very obvious linear relationship between the two.This indicates that the width of the gamma ray spectra is likely to indicate the ability of valence electrons to attract positrons.3.This paper defines a new physical quantity: average doppler shift(ADS).ADS comes from integrating the entire gamma-ray spectra,which is averaging all the points in the gamma-ray spectra.Unlike FWHM,which represents only a particular point in the spectra,ADS uses all gamma-ray spectral points,and all gamma-ray spectral information is in ADS,so it is more general than FWHM.4.In this paper,ADS of 36 A group atoms in element 1-56 are calculated and compared with FWHM and electronegativity of these atoms.The results show that,for the A group elements,ADS has the same change as electronegativity,and has a strong linear relationship with electronegativity.Therefore,we showed that ADS can represent the gamma-ray spectra exactly like FWHM and can serve as an indicator of the positrophilic electrons in atoms.In summary,this paper introduces ADS instead of FWHM to represent the characteristics of the gamma-ray spectra,which can more accurately describe the gamma-ray spectra,and by comparing a series of atomic valence electron theory gamma-ray spectra width and electronegativity,the analysis quantitatively proved for the first time that positrophilic electrons in the positron-electron annihilation process are valence electrons.