Discovery of enhanced nuclear stability near the deformed shells N=162 and Z=108.

In bombardments of [sup 248]Cm with [sup 22]Ne we discovered two new isotopes, [sup 265]106 and [sup 266]106, by establishing genetic links between their [alpha] decays and spontaneous fission (SF) or [alpha] decays of the daughter nuclides. We measured [ital E][sub [alpha]]=8.63[plus minus]0.05 MeV for [sup 266]106 and a half-life of 1.2 s for its daughter [sup 262]104. For [sup 265]106 we measured [ital E][sub [alpha]]=8.71 to 8.91 MeV. From these [alpha] energies we estimated [alpha] half-lives of 10--30 s for [sup 266]106 and 2--30 s for [sup 265]106. We estimated SF branches of 50% or less for both isotopes. The decay properties of [sup 266]106 establish the existence of enhanced nuclear stability near the predicted deformed shells [ital N]=162 and [ital Z]=108.