The two-neutrino double beta decay of ${}_{}{}^{82}{}_{}{}^{}\mathrm{Se}$ has been measured during a 20 244 h run resulting in a half-life of 1.${08}_{\mathrm{-}0.06}^{+0.26\mathrm{}}$×${10}^{20}$ years (68% C.L.). No candidate events for the zero-neutrino double beta decay during 21 924 h results in a half-life limit of 2.7×${10}^{22}$ years at the 68% confidence level.

• Received 26 May 1992

DOI:https://doi.org/10.1103/PhysRevC.46.1535