Formation of superheavy elements in the capture of very heavy ions at high excitation energies

Abstract

The potential barriers governing the reactions 58Fe+244Pu, 238U+64Ni, and 238U+72Ge have been determined from a liquid-drop model taking into account the proximity energy, shell energies, rotational energy, and deformation of the incoming nuclei in the quasimolecular shape valley. Double-humped potential barriers appear in these entrance channels. The external saddle-point corresponds to two touching ellipsoidal nuclei when the shell and pairing effects are taken into account, while the inner barrier is due to the shell effects at the vicinity of the spherical shape of the composite system. Between them, a large potential pocket exists and persists at very high angular momenta allowing the capture of very heavy ions at high excitation energies

Production of proton-rich nuclei around Z = 84-90 in fusion-evaporation reactions

“…The structure properties of the proton-rich nuclei (PRN) associated with the fission barrier, density profiles of neutrons and protons, proton-drip line, level spectra etc would be helpful to extend the superheavy region. A number of models have been developed for understanding the formation mechanism of superheavy nuclei and heavy PRN in the fusion-evaporation reactions [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. The formation of superheavy nuclei in the massive fusion reactions is hindered due to the quasifission process.…”