Island of stability for superheavy elements and the dynamical cluster-decay model for fusion evaporation residue cross sections:⁴⁸Ca+²³⁸U→²⁸⁶112* as an example

Abstract

The dynamical cluster-decay model (DCM), with deformation effects up to hexadecapole deformations and 'compact' orientations included, is used to calculate the fusion evaporation residue cross sections σ ER for 3-and 4-neutron emission in a hot fusion reaction 48 Ca+ 238 U→ 286 112 * at various incident energies, taking three different proton magic numbers Z = 114, 120 or 126 and N = 184 for the superheavy region. In each case, the shell corrections are obtained from an 'empirical' formula, with the corresponding liquid drop energies adjusted to give the experimental binding energies. This is done for all possible mass (and charge) fragmentations of the compound system. The DCM gives a good description of the measured fusion excitation function, σ ER (=σ 3n +σ 4n ) as a function of the compound nucleus excitation energy E * , within one parameter fitting, the neck length R(E * ). Of all the three choices of magic numbers, the fusion evaporation residue cross section remains the largest for the case of Z = 126, N = 184, and the lowest for the Z = 114, N = 184 case, thereby clearly suggesting that Z = 126, N = 184 are the strongest magic numbers (largest shell corrections), and Z = 114, N = 184 are the weakest (smallest shell corrections), with Z = 120, N = 184 lying in between. Thus, the present study seems to support the island of stability for superheavy nuclei centering around Z = 126, N = 184, rather than around Z = 114, N = 184, with Z = 120, N = 184 as the second best possibility.

Temperature-dependent binding energies in a dynamical cluster-decay model applied to the decay of hot and rotating56Ni*

“…The dynamical cluster-decay model (DCM), a nonstatistical description, was developed by Gupta and collaborators [17][18][19][20][21][22][23][24][25][26][27][28][29][30] to account for the emission of both light particles and intermediate and/or heavy mass fission fragments from the excited CN. Initially, within a renormalization procedure, the DCM is used to calculate decay constants (for s waves) and total kinetic energies [17,18].…”

Role of rotational energy component in the dynamics of 16O+198Pt reaction

“…The sticking limit (I S ) is more appropriate [6] for the use of proximity potential with neck-length surface ≤2 fm, which has the consequences that, the limiting angular momentum is much larger in this case as compared to I NS limit where lesser number partial waves contribute towards cross-sections. The previous studies [7,8,10,11] suggests that, both I S and I NS limits are equally good to study evaporation residue process, although, in fission process I S seems to perform better [6,11]. These observations are for independent addressal of ER and fission paths governed in independent reactions induced via heavy ion collisions.…”

Study of the decay of291115* formed in48Ca+243Am reaction

“…In DCM [2][3][4], the compound nucleus decay cross-section, in terms of ℓ partial waves, is defined as…”

“…spontaneous fission increases immensely. To explore the structural and stability aspects of odd-Z region further, 243 Am+ 48 Ca→ 291 115* [1] is studied within the framework of DCM [2][3][4]. For proton and neutron magic shells, we take Z=126 and N=184, as suggested by Gupta et al [3].…”