IDENTIFICATION OF NEW MENDELEVIUM AND EINSTEINIUM ISOTOPES IN BOMBARDMENTS OF BI-209 WITH AR-40

The four new neutron deficient isotopes Md-246 (T-1/2 = (1.0 +/- 0.4) s), Md-245 (T-1/2 = (0.35(-0.16)(+0.23)) s), Es-242 (T-1/2 = (16(-4)(6)) s) and Es-241(T-1/2 = (8(-4)(+6)) s) were produced in fusion react ions of Ar-40 ions with Bi-209 targets at bombarding energies of E(p) = 4.78, 4.93 and 5.12 A MeV. The assignment was based on evaporation residue-alpha-alpha time and position correlations. A spontaneous fiss ion activity of T-1/2=(0.90 +/- 0.25)ms was observed at a projectile e nergy of E(p) = 5.12 AMeV and assigned to Md-245.