Low energy gamma radiation （0.2-10.0） MeV near the Earth＇s surface has several origins. Primary and secondary cosmic radiations with interactions of very high energy protons （〉 1 GeV） in terrestrial atmosphere a...Low energy gamma radiation （0.2-10.0） MeV near the Earth＇s surface has several origins. Primary and secondary cosmic radiations with interactions of very high energy protons （〉 1 GeV） in terrestrial atmosphere are the main sources. The second most important source near the surface of the Earth and in the tropical and equatorial regions is the radon gas （Rn-222） that decays in alpha particles and gamma rays in this energy range. Also the telluric radionuclides 238U, 235U, 40K and 232Th in decays produce gamma radiation with different intensities at different locations on the surface of the Earth. Other sources less present are electrical discharges （lightning strikes） and man-made radioactive sources for medical, dental and industrial applications. In this work, it is shown that measurements of these components during all year 2016 are carried out at the ITA （Technological Institute of Aeronautics） campus in Sao Jose dos Campos, SP, Brazil and their possible correlations with atmospheric phenomena.展开更多
The α-preformation probability is directly deduced from experimental α decay energies and half-lives in an analytical way without any modified parameters. Several other model-deduced results, are used to compare wit...The α-preformation probability is directly deduced from experimental α decay energies and half-lives in an analytical way without any modified parameters. Several other model-deduced results, are used to compare with that of the present study. The key role played by the shell effects in the v-preformation process is indicated in all these cases. In detail, the α-preformation factors of different theoretical extractions are found to have similar behavior for one given isotopic chain, implying the model-independent varying trend of the preformation probability of α particle. In addition, the formation probability of heavier particle in cluster radioactivity is also obtained, and this confirms the relationship between the cluster preformation factor and the product of the cluster and daughter proton numbers.展开更多
基金National Natural Science Foundation of China(11205083,11505100)Construct Program of the Key Discipline in Hunan Province,Research Foundation of Education Bureau of Hunan Province,China(15A159)+2 种基金Natural Science Foundation of Hunan Province,China(2015JJ3103,2015JJ2121)Innovation Group of Nuclear and Particle Physics in USCShandong Province Natural Science Foundation,China(ZR2015AQ007)~~
文摘Low energy gamma radiation （0.2-10.0） MeV near the Earth＇s surface has several origins. Primary and secondary cosmic radiations with interactions of very high energy protons （〉 1 GeV） in terrestrial atmosphere are the main sources. The second most important source near the surface of the Earth and in the tropical and equatorial regions is the radon gas （Rn-222） that decays in alpha particles and gamma rays in this energy range. Also the telluric radionuclides 238U, 235U, 40K and 232Th in decays produce gamma radiation with different intensities at different locations on the surface of the Earth. Other sources less present are electrical discharges （lightning strikes） and man-made radioactive sources for medical, dental and industrial applications. In this work, it is shown that measurements of these components during all year 2016 are carried out at the ITA （Technological Institute of Aeronautics） campus in Sao Jose dos Campos, SP, Brazil and their possible correlations with atmospheric phenomena.
基金the National Natural Science Foundation of China (Grant Nos. 11035001, 10975072, 10735010 and 11120101005)the National Major State Basic Research and Development of China (Grant Nos. 2010CB327803 and 2013CB834400)+4 种基金the Knowledge Innovative Program of the Chinese Academy of Sciences (Grant No. KJCX2-SW-N02)the Research Fund of Doctoral Point (RFDP) (Grant No. 20100091110028)the Project Funded by the Priority Academic Programme Development of Jiangsu Higher Education Institutions (PAPD)the Research and Innovation for College Postgraduate of JiangSu Province (Grant No. CXZZ12 0031)the Science and Technology Development Fund of Macao (Grant No.068/2011/A)
文摘The α-preformation probability is directly deduced from experimental α decay energies and half-lives in an analytical way without any modified parameters. Several other model-deduced results, are used to compare with that of the present study. The key role played by the shell effects in the v-preformation process is indicated in all these cases. In detail, the α-preformation factors of different theoretical extractions are found to have similar behavior for one given isotopic chain, implying the model-independent varying trend of the preformation probability of α particle. In addition, the formation probability of heavier particle in cluster radioactivity is also obtained, and this confirms the relationship between the cluster preformation factor and the product of the cluster and daughter proton numbers.
