Natural radiative lifetimes in the $3\mathrm{sns} {}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}$ and $3\mathrm{snd} {}_{}{}^1{}_{}{}^{}D_2^{}{}_{}{}^{}$ sequences of magnesium

Natural radiative lifetimes have been determined in the determined in the $3\mathrm{sns} {}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{} \mathrm{}(n=4-15\mathrm{})\mathrm{}$ and the $3\mathrm{snd} {}_{}{}^1{}_{}{}^{}D_2^{}{}_{}{}^{} \mathrm{}(n=3-15\mathrm{})\mathrm{}$ sequences of Mg I employing a pulsed-laser system. The radiative lifetimes in the ${}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}$ sequence and of the higher members in the ${}_{}{}^1{}_{}{}^{}D_2^{}{}_{}{}^{}$ sequence are unperturbed and scale as ${\left(n^{*}\right)}^{2.6}$ (where $n^{*}$ is the effective principal quantum number), while the lifetimes of the lower members in the ${}_{}{}^1{}_{}{}^{}D_2^{}{}_{}{}^{}$ sequence are perturbed by the doubly excited $3p^2$ configuration. The measured lifetimes are compared with available theoretical calculations, and a very good agreement is obtained.