Decay of dinuclear systems formed from dubnium

The radioactivity of the superheavy nuclei ^250−275Db is studied and presented using the Coulomb and proximity potentials. The half-lives corresponding to different decay modes such as α, cluster decay (¹²C, ¹⁴N, ^18,20O, ²³F, ²⁰Ne, ³⁴S, ²⁸Mg and ⁴⁰Ca) and spontaneous fission in the superheavy nuclei ^250−275Db are studied. The studied half-lives are compared with the available experiments. The decay modes and the branching ratios of isotopes of dubnium are presented. The isotopes of dubnium, ^254−263Db, are identified as α emitters, whereas isotopes such as ^250−253Db and ^264−275Db are identified as having spontaneous fission. The identified alpha emitting isotopes of dubnium have decay energies from 6 MeV to 10 MeV and half-lives 1 ms to 100 s. The possible projectile–target combinations to synthesise the superheavy nuclei ^253−263Db were predicted. The fusion of spherical projectile and target yields larger evaporation residue cross-sections. (author)