Rafael Van den Bossche

Superheavy elements (SHE) have an atomic number Z ≥ 104, and their existence was predicted almost 50 years ago due to quantum shell effects that influence their stability and decay [1]. SHE production is very challenging (due to very small cross sections in the range of a few picobarns or less), with complete fusion of heavy ions being one of the most successful ways of producing SHEs. The complete fusion mechanism produces neutron-deficient SHEs, making investigation into new methods of production crucial for further progress in SHE research.

The aim of the project is to investigate the incomplete fusion of neutron-rich projectiles with heavy stable targets, following the binary fragmentation of a projectile at Coulomb energies. This mechanism has not been thoroughly explored yet, and could prove to be an effective way of producing neutron-rich SHE isotopes with low excitation energies [2].

To this aim, a semi-classical dynamical model is being developed by combining a classical trajectory model with stochastic breakup, as implemented in the PLATYPUS code [3], with a dynamical fragmentation theory [4] treatment of two-body clusterisation and decay of a projectile. A finite-difference method solution to the time-independent Schrödinger equation in the charge asymmetry coordinate is being explored by way of diagonalising a tridiagonal matrix with periodic boundary conditions.

Ultimately, this new model will be tested against existing experimental data [2] and used to make predictions for producing new SHE isotopes in future experiments planned at the Joint Institute for Nuclear Research in Dubna, Russia, and elsewhere [5].

References:

[1] S. Hofmann et al., Eur. Phys. J. A 52 (2016) 180.

[2] C. Borcea et al., Nucl. Phys. A 415 (1984) 169, and references therein.

[3] A. Diaz-Torres, J. Phys. G 37 (2010) 075109; Computer Physics Communication 182 (2011) 1100.

[4] S.N. Kuklin et al., Eur. Phys. J. A 48 (2012) 112.

[5] C. Borcea et al., “Superheavy Elements: A New Paradigm”, Proc. Int. Symp. on `````Exotic Nuclei (EXON-2016), http://www.worldscientific.com/doi/abs/10.1142/9789813226548_0021.