Possible syntheses of unknown superheavy 309,312126 nuclei

Novel semi-empirical formula and examination for fission barriers of super-heavy nuclei with Z ≥ 100

“…According to various reports [4,9,10], the observed uncertainty can lead to a variation of up to 6 orders of magnitude in the SHN production cross sections. In practice, a change of one order of magnitude in the cross section may extend the beamtime from several months to one year at accelerator facilities.…”

“…This enables evaluation of the competition between the α decay and fission processes. Indeed, calculations of the cross sections and the spontaneous fission lifetime strongly depend on the fission width of a formed compound nucleus [1][2][3][4][5][6]. Because the fission decay width is exponentially proportional to the fission barrier [7,8], the cross sections and the fission lifetime are highly sensitive to this barrier.…”

“…Because the fission decay width is exponentially proportional to the fission barrier [7,8], the cross sections and the fission lifetime are highly sensitive to this barrier. It has been reported that an uncertainty of 1MeV in the fission barrier can result in a difference of one order of magnitude in calculated the cross sections [4,9,10]. This can lead to major difficulties in conducting experiments; that is, the beamtime of accelerator facilities may change from a few months to years.…”

“…), which generate unavoidable uncertainties [11][12][13][14]. For instance, the shell damping energy (E d ), to which the level parameter is exponentially proportional [15,16], can be varied from 13MeV to 25 MeV [13], leading to a change of up to a few orders of magnitude in the evaporation residue cross sections [4,17] of SHN production cross sections. Another factor that affects the determination of the fission barrier is the viscosity coefficient, which has a value in the range of 1×10 −21 -30×10 −21 s −1 [1] (and therein).…”