The difference in the decay constants of ${\mathrm{Be}}^7$ in Be, BeO, and Be${\mathrm{F}}_2$, have been measured using the differential ionization chamber technique. The results are $\lambda \left(\mathrm{Be}\right)-\lambda \left(\mathrm{Be}{\mathrm{F}}_2\right)=(7.41\mathrm{}\pm 0.47)\times {10}^{-4\mathrm{}}\lambda$, $\lambda \left(\mathrm{BeO}\right)-\lambda \left(\mathrm{Be}{\mathrm{F}}_2\right)=(6.09\mathrm{}\pm 0.55)\times {10}^{-4\mathrm{}}\lambda$, $\lambda \left(\mathrm{Be}\right)-\lambda \left(\mathrm{BeO}\right)=(1.31\mathrm{}\pm 0.51)\times {10}^{-4\mathrm{}}\lambda$. These values are smaller than the results previously obtained by Leininger, Segrè, and Wiegand for the same compounds, but support their earlier work.

• Received 2 February 1953

DOI:https://doi.org/10.1103/PhysRev.90.610