Systematic study of cluster radioactivity half-lives based on a modified Gamow-like model

In this study, taking into account of the contribution of the centrifugal potential on half-life and the effect of electrostatic shielding, we modify the Gamow-like model proposed by Zdeb et al. [Phys. Rev. C 87, 024308 (2013)] to systematically investigate the cluster radioactivity half-lives of nuclei ranging from 221Fr to 238U. The calculated results can reproduce the experimental data well. Additionally, this modified Gamow-like model is applied to predict the half-lives of cluster radioactivity nuclei whose experimental half-lives have the lower limit. It is found that the predicted results are in good agreement with the ones obtained by using the Gamow-like model and a Viola-Seaborg type formula.

Proton radioactivity of nuclei with atomic numbers Z = 51–91 and mass number 104–211

Proton radioactivity of neutron-deficient nuclei with atomic numbers [Formula: see text]–91 and mass number 104–211 is investigated using the analytical super-asymmetric fission (ASAF) model — a model used to study [Formula: see text]-decay and cluster radioactivity since 1984. The experimental [Formula: see text] values are compared with calculated ones based on WS4 (Y. Z. Wang et al., 2014–2015), and in few cases KTUY05 (H. Koura et al., 2005) mass models. Proton drip-line and neutron drip-line are determined using the WS4 mass model. We compare the calculated results with experimental half-lives, showing good agreement.

Theoretical cluster decay predictions for the nuclei 245−260Md with different nuclear potentials

We have studied systematically the alpha decay and cluster radioactivity half-life of heavy [Formula: see text]Mendelevium ([Formula: see text]) isotopes. The alpha decays from Md isotopes have been studied within the framework of Coulomb and proximity potential model using 14 different versions of nuclear potentials. Also, we have studied the half-lives of alpha decay of Md nuclei within the nuclear potentials generalized liquid drop model (GLDM) and also within GLDM with modified different nuclear potentials, namely proximity potential 2010, 1977, 1988, 2000 and 2002. Moreover, the half-lives of the [Formula: see text]-decay and cluster radioactivity calculated using the Universal formula for cluster decay (UNIV) of Poenaru et al., the Universal decay law (UDL) of Qi et al. and the Unified formula of half-lives for both the [Formula: see text]-decay and cluster radioactivity (UFADCR) of Ni et al. and found to be in good agreement. Our results have been compared with experimental data and demonstrate the acceptability of the approach. Among the different proximity potentials, GLDM with proximity 1977 version (GLDM[Formula: see text][Formula: see text][Formula: see text]P77) ([Formula: see text]) provides the best description for alpha decay studies with low deviation.

Cluster Radioactivity

Cluster radioactivity (spontaneous emission of heavy particles from nuclei) is presented from theoretical point of view in good agreement with experimental results. After a brief hystorical account we give details about the analytical super asymmetric fission (ASAF) model extensively used for predicting the half-lives of heavy and superheavy (Z ≥ 104) elements. For the already measured 26 cluster decays (from 14C to 32,34Si of parent nuclides with Z = 87-96) it is clear that cluster radioactivity is a rare phenomenon in the best case about 9 orders of magnitude weaker than the competing alpha decay. Then we show the theoretical possibility of a strong cluster decay compared to alpha decay for some superheavy nuclei with Z ≥ 122, e.g. 306122; 310-314122; 306-324124, and 311-323124.

Cluster radioactivity in superheavy nuclei 299-306122

Cluster radioactivity is an intermediate between alpha decay and spontaneous fission. It is also an exotic decay obtained in superheavy nuclei. When a cluster decay is detected in superheavy nuclei, the daughter nuclei is having near or equal to doubly magic nuclei. We have investigated cluster decay of isotopes of He, Li, Be, Ne, N, Mg, Si, P, S, Cl, Ar and Ca in the superhaevy nuclei region 299-306122. We have also compared the logarithmic half-lives of cluster decay with that of other models such as Univ [1], NRDX [2], UDL [3] and Horoi [4]. From this study it is concluded that cluster decay of 4He, 22Ne, 26Mg, 28Si 30Si, 34S, 40Ca and 46Ca are having shorter logarithmic half-lives compared to exotic cluster decay modes.