Systematic shell-model study of Rn isotopes with $A=$ 207 to 216 and isomeric states

Abstract

In the present work, we have performed systematic large-scale shell-model calculations for Rn isotopes with A = 207 to 216. For the 207−212 Rn isotopes, we have performed calculations with KHH7B interaction, while for 213−216 Rn isotopes with KHPE and KHH7B interactions. Calculations have been carried out with the KHH7B in a model space consisting of the proton orbitals d 5/2 , h 11/2 , d 3/2 and s 1/2 below the Z = 82 shell gap, and the h 9/2 , f 7/2 , and i 13/2 above it, and for neutron, the i 13/2 , p 3/2 , f 5/2 , and p 1/2 orbitals are below N = 126 shell gap, and the g 9/2 , i 11/2 , j 15/2 orbitals are above it. The calculations for KHPE interaction are performed in the full Z = 82-126 protonneutron model space with proton orbitals h 9/2 , f 7/2 , f 5/2 , p 3/2 , p 1/2 , and i 13/2 , and neutron orbitals i 11/2 , g 9/2 , g 7/2 , d 5/2 , d 3/2 , s 1/2 , and j 15/2 . The calculated energies and electromagnetic properties have been compared with the available experimental data. We have also analyzed several isomeric states from the calculated shell-model configurations and half-lives. In the case of even Rn isotopes, the 81 + isomeric state is due to seniority v =2, the 141 + and 171 − isomeric states are due to seniority v =4. For the odd Rn isotopes, the 13/21 + isomeric state is due to seniority v =1, the 35/21 + , 43/21 − and 49/21 + isomeric states are due to seniority v = 5. We have also suggested spins and parities of several unconfirmed states from the recent experimental data.