The upgrade of the kinematic separator VASSILISSA—experimental results and plans

Within the past twelve years, the recoil separator VASSILISSA has been used for the investigations of evaporation residues produced in heavy-ion-induced complete fusion reactions. In the course of the experimental work, fourteen new isotopes have been identified by the parent-daughter correlations in the region of elements with 92≤Z≤94. The study of the decay properties and formation cross sections of the isotopes of elements 110, 112, and 114 was performed using high-intensity ⁴⁸Ca beams and ²³²Th, ²³⁸U, and ²⁴²Pu targets. At the beam energies corresponding to the calculated cross-section maxima of the 3n evaporation channels, the isotopes ²⁷⁷110, ²⁸³112, and ²⁸⁷114 were produced and identified. For further experiments aimed at the synthesis of the superheavy element isotopes (Z≥110) with the use of intensive ⁴⁸Ca extracted beams, improvements in the ion optical system of the separator and the focal plane detector system have been made.