Probing Optimal Reaction Energy for Synthesis of Element 119 from ⁵¹V+²⁴⁸Cm Reaction with Quasielastic Barrier Distribution Measurement

Abstract

Here, the quasielastic barrier distribution of <sup>51</sup>V+<sup>248</sup>Cm was extracted by measuring the excitation function of quasielastic backscattering using a gas-filled recoil ion separator, GARIS-III. The obtained barrier distribution is well explained by the coupled-channels calculation, indicating a significant effect of the rotational excitation of deformed <sup>248</sup>Cm. From the measured average Coulomb barrier height and deformation parameters of <sup>248</sup>Cm, the side-collision energy leading to a compact configuration of colliding nuclei was obtained. The relation between the side collision energy and the excitation function of the evaporation-residue cross sections in the <sup>48</sup>Ca+<sup>248</sup>Cm system was evaluated as a reference for the <sup>51</sup>V+<sup>248</sup>Cm case. The optimal reaction energy to synthesize a new element 119 at the <sup>51</sup>V+<sup>248</sup>Cm fusion reaction (3n and 4n channels) was estimated with an aid of these experimental data.