New Ways for Producing Heavy Exotic Nuclei

Heavy exotic nuclei are usually produced in fragmentation reactions at relativistic energies or in complete fusion reactions at Coulomb barrier energies. Projectile fragmentation allows to reach nuclei up to Z = 92. To enter the transuranium region, fusion reactions are applied which, however, lead to relatively neutron-deficient isotopes due to the bending of the stability line toward the neutron axis. This causes the necessity for novel synthesis methods. Possible options are multinucleon transfer reactions or, in the future, fusion reactions with radioactive projectile beams. Both possibilities will be discussed. Multinucleon transfer reactions are presently investigated in several laboratories around the world with respect to their capacity for isotope production. Recently, we succeeded at the velocity filter SHIP at GSI to observe several new transuranium isotopes which were produced in multinucleon transfer reactions in collisions of ⁴⁸Ca + ²⁴⁸Cm. These first results reveal that this reaction type together with fast and sensitive separation and detection techniques is promising for the synthesis of new isotopes in the region of heaviest nuclei.