Search for Double Beta Decay inNd150

Lower limits were obtained for the half-life of the double beta decay of ${\mathrm{Nd}}^{150}$ using thin plastic scintillation detectors surrounded by a large liquid scintillation anticoincidence shield. The experiment was performed 585 m underground in the relatively low-radioactive-background environment of a salt mine. The observed count rates are consistent with a lower limit of 3×${10}^{17}$ years for the half-life of the decay ${\mathrm{Nd}}^{150}\to {\mathrm{Sm}}^{150}+2\mathrm{}{e}^{-}+2\mathrm{}{\overline{v}}_e$ and 5×${10}^{18}$ years for the decay ${\mathrm{Nd}}^{150}\to {\mathrm{Sm}}^{150}+2\mathrm{}{e}^{-}$. A lower limit of ∼${10}^{17}$ years was also obtained for the single beta decay ${\mathrm{Nd}}^{150}\to {\mathrm{Pm}}^{150}+e^{-}+{\overline{v}}_e$.