Naturally occurringαemitters with extremely long half-lives are investigated using the latest experimental data.Within the time-dependent perturbation theory,αdecay with a rather narrow width is treated as a quasi-s...Naturally occurringαemitters with extremely long half-lives are investigated using the latest experimental data.Within the time-dependent perturbation theory,αdecay with a rather narrow width is treated as a quasi-stationary problem by dividing the potential between the α particle and daughter nucleus into a stationary part and a perturbation.The experimentalαdecay half-lives of seven available long-livedαemitters with T^(total)_(1/2)>10^(14)y are reproduced with a good accuracy.It is also found that the deformation effect should be treated carefully for long-lived nuclei,especially with low Q_(α) values.Predictions of the α decay half-lives of twenty naturally occurring nuclei are provided,namely,^(142)Ce,^(145,146)Nd,^(149)Sm,^(156)Dy,^(162,164)Er,^(168)Yb,^(182,183,184,186)W,^(187,188,189,190)Os,^(192,195)Pt,and^(204,206)Pb.These nuclei are energetically unstable to α decay with low decay energies and extremely long decay half-lives.In particular,the candidates^(187)Os and^(149)Sm are strongly recommended for future experiments.展开更多
基金Supported by the National Natural Science Foundation of China(11822503)the Fundamental Research Funds for the Central Universities(Nanjing University)。
文摘Naturally occurringαemitters with extremely long half-lives are investigated using the latest experimental data.Within the time-dependent perturbation theory,αdecay with a rather narrow width is treated as a quasi-stationary problem by dividing the potential between the α particle and daughter nucleus into a stationary part and a perturbation.The experimentalαdecay half-lives of seven available long-livedαemitters with T^(total)_(1/2)>10^(14)y are reproduced with a good accuracy.It is also found that the deformation effect should be treated carefully for long-lived nuclei,especially with low Q_(α) values.Predictions of the α decay half-lives of twenty naturally occurring nuclei are provided,namely,^(142)Ce,^(145,146)Nd,^(149)Sm,^(156)Dy,^(162,164)Er,^(168)Yb,^(182,183,184,186)W,^(187,188,189,190)Os,^(192,195)Pt,and^(204,206)Pb.These nuclei are energetically unstable to α decay with low decay energies and extremely long decay half-lives.In particular,the candidates^(187)Os and^(149)Sm are strongly recommended for future experiments.
