Fission mass distribution of various superheavy nuclei and related dynamical analysis

Abstract

The fission mass distribution of Z=104-120 superheavy nuclei formed in 238U-induced reactions is investigated using the dynamical cluster decay approach. The cross-section for the formation of symmetric fragments with masses A2±20 of 274Hs⁎, 286Cn⁎, 286Fl⁎, and 302120⁎ nuclei are calculated over a wide energy spectrum by rationalizing the neck-length parameter (ΔR). The calculations are carried out by including the quadrupole (β2i)-deformation of the fragments using hot and cold optimum orientation approaches. Within hot orientation criteria, symmetric fission distribution is observed for 274Hs⁎ nucleus which becomes highly asymmetric in nature for 302120⁎ compound system. The lead (Pb)-peaks originating due to quasi-fission process start competing while going from 274Hs⁎ to 302120⁎ nucleus. Additionally, the role of cold orientation approach is also explored for these nuclei which show the opposite trend in the mass distribution while going from Z=108 to Z=120 superheavy system. Further, the fission and asymmetric quasi-fission cross-sections are predicted for various entrance channels i.e. 58Fe+244Pu, 54Cr+248Cm, and 50Ti+249Cf and compared with experimentally available data of 64Ni+238U reaction to identify the favorable projectile-target combination for the synthesis of Z=120 nucleus. The results show that because of larger fusion probability, 50Ti+249Cf reaction seems to provide a favorable option for the synthesis of Z=120 superheavy nucleus.