New approaches to production scenarios of heavy and superheavy nuclei

• Applicants: Privatdozentin Dr. Sophie Heinz; Professor Dr. Horst Lenske
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: since 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 317612660

Theory (H. Lenske):- Fusion, fission and multinucleon transfer (MNT) reactions of heavy ions will be investigated, especially for the exploratory studies of SHE and exotic isotope production. The previously developed theoretical formalism will be applied to the evolution of nuclear systems in complex potential landscapes created by nuclear shell and additional quantum effects. Nuclear fission will be studied with the aim to explain the coexistence of symmetric and asymmetric fission modes even at high excitation energies.- As a new topic, we set a stronger focus on non-equilibrium dynamics and, in that context, explore the use of lattice theory as a potentially powerful method for numerical simulations of many-body systems. Special emphasis will be put on the description of dissipation by random forces. - As a tempting further application, we use the same (numerical) methods for the description of stellar mergers. The previous fix point analysis showed that di-star systems are driven to mass equilibration. In the upcoming funding period, the approach will be extended to dissipative interactions, to be treated by the Langevin approach.Experiment (S. Heinz)- The experimental program on MNT reactions will focus on new experiments. The so far obtained results revealed that MNT reactions are a promising method to synthesize predominantly very neutron-deficient transuranium isotopes. In a one day experiment at the velocity filter SHIP of GSI we discovered five new isotopes with Z≥92 in this region of the nuclide chart and observed nine already known MNT products with 98 ≤ Z ≤ 102.- A new experiment will take place in April 2020 at the new velocity filter SHELS of JINR Dubna. One main goal is the synthesis of further new neutron-deficient transuranium isotopes, especially around the N=126 shell. Also, further studies of MNT products with Z≥100 will take place, and excitation functions will be measured. A second experiment will focus on the region of neutron-rich MNT products below Pb.- Based on the results from previous studies, the new experiments will be conducted with optimized settings and considerably longer beam times. Also, the SHELS data acquisition system is 10 times faster than the one which we used in previous experiments, and there is an efficient array of gamma detectors available. The latter one being of special interest for the identification of beta emitters.

• DFG Programme: Research Grants