Shell inhibition on production of N=126 isotones in multinucleon transfer reactions

The multinucleon transfer process is one promising approach to produce exotic nuclei around the last waiting point in the r-process. However, the reliable reaction combinations are still ambiguous so far. We quantitatively evaluate the relative shell inhibition on production cross sections for producing N = 126 isotones for the first time with definition of a relative shell inhibition factor. The results suggest that the combinations characterized by double closed shell structure are unfavorable for producing unknown N = 126 isotones. It is demonstrated that the reactions Xe-136 + Pb-208 and Xe-136 + Pt-198 are not the good candidates. By investigating the yield contributions in main evaporation channels, we find that for producing W-200 the effects of shell structure on production cross sections are mainly from de-excitation process. Also, the weak incident energy dependence of cross sections for producing N = 126 isotones is revealed with relevance between evaporation probabilities and excitation energy distributions of primary fragments. (C) 2021 The Author(s). Published by Elsevier B.V.

Automated summary

The study quantitatively evaluated the impact of relative shell inhibition on the production cross sections of N=126 isotones for the first time, indicating that combinations characterized by double closed shell structure are unfavorable for producing unknown N=126 isotones. The effects of shell structure on production cross sections are mainly from the de-excitation process.