Previous observation of heavy-ion emission from ${}_{}{}^{226}{}_{}{}^{}\mathrm{Ra}$ has been confirmed. Charge and energy of the emitted fragment were measured using thin ${}_{}{}^{226}{}_{}{}^{}\mathrm{Ra}$ sources and polycarbonate track-recording films. Decay by ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$ emission could be identified unambiguously. The track-detector was calibrated with tandem-accelerated ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ ions and tested by observing the ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$ emission from ${}_{}{}^{223}{}_{}{}^{}\mathrm{Ra}$ yielding a branching ratio of (5.0±1.0)×${10}^{\mathrm{-}10}$. In the case of ${}_{}{}^{226}{}_{}{}^{}\mathrm{Ra}$ our result for the ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$/α ratio is (2.3±0.8)×${10}^{\mathrm{-}11}$. Estimates of partial half-lives of Ra isotopes for ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$ emission are discussed.

• Received 20 January 1989

DOI:https://doi.org/10.1103/PhysRevC.41.778