GALS - setup for production and study of multinucleon transfer reaction products: present status

Abstract

Abstact. This is a brief report on the current status of the new GAs cell based Laser ionization Setup (GALS) at Flerov Laboratory for Nuclear Reactions (FLNR) -JINR, Dubna. GALS is planned to exploit available beams from the U-400M cyclotron in low energy multi-nucleon transfer reactions to study exotic neutron-rich nuclei located in the "north-east" region of nuclear map. Products from 4.5 to 9 MeV/nucleon heavy-ion collisions, such as 136 Xe on 208 Pb, are to be captured in a gas cell and selectively laser-ionized in a sextupole (quadrupole) ion guide extraction system. PACS: 25.60.Je, 28.60.+s, 42.62.Fi IntroductionThe heavy neutron rich nuclei in the "north-east" part of the nuclide chart are from extremely importance for nuclear physics investigations, especially for the understanding of astrophysical nucleosynthesis and rprocess. The closed neutron shell N = 126-the so called last "waiting point" for the r-process-is located just in this region (figure 1). Neutron shell N = 126 is a classical shell closures for nuclei along the line of stability. However, as one moves away from the line of stability, abrupt changes in nuclear structure can arise. Especially, appearance of new magic numbers and/or disappearance of traditional ones as well as the onset of deformation are expected, as e.g. already observed in the region of lighter nuclei. Study of the structural properties of nuclei along the neutron shell N = 126 could contribute to the current discussion about the quenching of shell gaps in nuclei with large neutron excess. A creation and launch of this facility will open a new field of research in low-energy heavy-ion physics, and new horizons in the study of unexplored "north-east" area of the nuclear map. It could be helpful also for finding a new way for the production of heavy and superheavy nuclei.