Theoretical studies on the alpha decay of 178–220Pb isotopes

The α   decay half lives for the isotopes of Pb (Z=82)(Z=82) nuclei in the range 178≤A≤220178≤A≤220 have been studied systematically within the Coulomb and proximity potential model (CPPM) and also within CPPM with modified deformation dependent assault frequency. The half-lives have been evaluated using the experimental Q   values. The computed half-lives are compared with the experimental data and also with the existing theoretical models and are found in good agreement. Using our model we could also demonstrate the influence of the neutron shell closure (N=126N=126) in the alpha decay half lives through the Geiger–Nuttall (GN) plots of ln⁡λln⁡λ vs. ZE−1/2ZE−1/2, log10⁡T1/2log10⁡T1/2 vs. Q−1/2Q−1/2 and −ln⁡P−ln⁡P vs. ZQ−1/2ZQ−1/2. We have also studied the Universal curve of log10⁡T1/2log10⁡T1/2 vs. −ln⁡P−ln⁡P, where all the alpha transitions could be plotted as a single line. The study on the various forms of GN plots, with various variables, enabled us in developing a new, simple relation for the alpha decay half lives of the Pb isotopes and our study also revealed that CPPM and CPPM with the modified assault frequency are appropriate for the alpha decay studies of Pb isotopes and thus can be successfully applied to other alpha emitter nuclides.