Lifetime of the 2(1)S0 state of heliumlike Ni26

We report the observation of the two-photon decay of the ${2}^{1}$${S}_{0}$ level in heliumlike ${\mathrm{Ni}}^{26+}$ and a measurement of the lifetime of this state. We find a lifetime of 150(16) ps, in agreement with the theoretical calculation of G. W. F. Drake [Phys. Rev. A 34, 2871 (1986)] which yields 154.3(5) ps.